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Corydoras slowly dying off one by one, no one has answers.     4/22/20
Hello. I am reaching out to you with a very strange problem that no one else seems to have any idea on what it could be.
<Understood.>
This involves my Bronze Corydoras, who all came from a clutch I hatched in June of 2018.
<Well done on the breeding, by the way!>
Before I go into the details of the problem, I'll do the important housekeeping of tank parameters. It's a planted 75 gallon, set up since February 2019, with plenty of caves and nooks for hiding. Substrate is a
fine gravel that they have no problem with, all have full bellies and long barbels.
<Still, as you seem to recognise, not ideal.>
Tankmates are 2 adult Bronze Cories, 4 Peppered Cories (I need to get more) and 15 Cherry Barbs.The problem has gone on for a long time though, so it is unrelated to tankmates.
<And Cherry Barbs are lovely fish that shouldn't cause any problems.>
Ammonia: 0ppm Nitrite: 0ppm Nitrate: 20ppm pH: 7.8-8.0 (I added driftwood yesterday, so this might change in the future.) Temp: 74-76F
<A little on the warm side for this/these catfish. Peppered Corydoras especially are low-end tropicals, even subtropicals, and thrive if given a cooler winter period. Around 18-22 C/64-68 F is ideal. Supposedly, wild fish can be found swimming under the ice on rare occasions! Bronze Corydoras are not quite so fond of cold, but still, I'd be keeping things towards the cool end of the range, maybe 22 C/72 F, and providing plenty of oxygen. Yes, the species is very adaptable, but if you're struggling with a
certain species, sometimes going back to basics, and seeing what "ideal conditions" would be can help, at the very least, in the dismissal of factors that aren't to blame.>
GH: 8-12 KH: 4-6
<Wouldn't expect much of a pH change with this much carbonate hardness, assuming regular water changes.>
Water changes: Weekly, 20%-40% depending on what is needed. Filtration: Marineland Penguin 200, Cascade 1000 Canister filter, a sponge filter
<All sounds fine, but how much water movement is at the bottom of the tank.
Put some flake down. Does it sit there? Or flap about weakly? Or is it quickly whooshed away in the current? Remember, slow water movement at the bottom of the tank means low oxygen levels. Not an issue for midwater barbs and tetras, which swim into strong water currents instinctively, and so get
more oxygen. But benthic fish, such as catfish and loaches, may struggle.
Sure, they can swim to the surface to gulp air, but that's not something most species are meant to do all the time, and indicates they're under a degree of stress.>
Treatments: Seachem Prime, Aquarium Co-op EasyGreen Food: Once a day feeding of any combination of Hikari Sinking Wafers, Omega One Catfish Sticks, Omega One Sinking Pellets, and Hikari Micropellets. Once a week I feed thawed frozen Brine Shrimp and Bloodworms, Omega One brand. Occasional treat of blanched veggies for them and the Cherry Barbs.
<All sounds fine.>
None of the other Cories have developed this, just these siblings. The symptoms are always similar. The Cory becomes lethargic, looses its appetite, and breathes rapidly. They often become dark in color and
sometimes, but not always, their eyes cloud over and they loose vision.
They never live for more than a few days after the symptoms first present.
It only ever effects one Cory at a time, and there's always a period of time between one showing symptoms. I don't believe it's related to water quality or diet, their foods have plenty of Vitamin A and I'm diligent about keeping things clean.
<But do see above re: water movement and oxygenation. If midwater fish are healthy, but you're losing benthic fish, that's a good clue there's something amiss "down deep" and your attention should be directed there.>
I've speculated that this is some sort of genetic problem. Their parents were chain pet store fish, and though their mom has always been very healthy, their dad was not the most robust, and he passed away without any cause or symptoms not too long ago.
<That can certainly be an issue, but if genetic, you'd expect to see deformities from the fry-stage onwards. While poor genes can indeed mean a weaker immune system, again, you'd expect to see this from the get-go, not months or years later. So while certainly a possibility, it would not be my first choice for an explanation.>
The fry did not have a good survival rate, and there were genetic abnormalities noticed in some of them as they got older. (Mainly, some of them developed very long fins, and all of those died from this condition.)
<Long-fin Corydoras are "a thing" in the trade, and yes, the inbreeding does make them a bit more delicate. Usually they're more prone to Finrot and other such afflictions of fish easily damaged or nipped.>
They also are slow growers, at nearly 2 years old they are nowhere near adult size.
<Odd.>
I'm down to 11 from over 30 juveniles that grew big enough to put in with the adults, most of them dying from this issue. I have yet another one who started showing symptoms last night. This Cory was absolutely fine the day before.
<Not good.>
At different times for different fish I've used Furan-2 and Amoxicillin in a 10 gallon quarantine tank. The fish always died overnight or the day after treatment. I have tried quarantining some of them and treating them with antibiotics, because the symptoms show some similarities to a bacterial infection, but they always die within a day or two of starting treatment. It seems like whatever this is, by the time symptoms show they're too far gone to treat.
<Understood.>
I'm at a complete loss here, I've asked other places and no one has any idea other than complete shots in the dark. This has been very hard to deal with, and I feel completely helpless. If anyone has any idea what this could be, or knows someone who might, please let me know.Below are images I've taken over the course of many months, in chronological order. Each one is of a different Cory who had this condition, the last one is currently suffering from this. The first one is one of the long fins I mentioned
earlier. I'm linking them because the images are very large.
<Appreciated.>
https://i.imgur.com/ALKc5MA.jpg
https://i.imgur.com/4Smpjb4.jpg
https://i.imgur.com/QlrQvDg.jpg
https://i.imgur.com/Zxs24th.jpg I appreciate any help you can give me. If you need any more information, I'm happy to supply it to the best of my abilities. - Adam
<Adam, my instinctive feeling is there's something environmental going on here. Get back to me when you've done the flake test on the substrate. If the water is rather still, I'd go with long-term oxygen stress, which combined with the higher than ideal temperature, could make the fish more
prone to opportunistic bacterial infections. I mean by that your fish are almost certainly dying from something like a Pseudomonas, Aeromonas, or Mycobacteria infection, but all of these are latent in even the best aquarium, and only cause problems when the fish's own immune system is compromised. Mycobacteria infections are notoriously difficult (i.e., impossible) to treat, but then again, even the more easily dealt with Aeromonas infections aren't going to go away if too far gone or the environment keeps the fish under stress. Cheers, Neale.>
Re: Corydoras slowly dying off one by one, no one has answers.    /RMF     4/22/20
<<Hi Bob! When you paste this up, can you add any thoughts of your own? I'm very open to ideas here! Neale.>>
<Sure; have read over, incl. your reps. First I would ask Adam to "check the checkers", to make sure the test kits (particularly ammonia and nitrite) are accurate. When the aquarist stirs, disturbs the substrate, do gas bubbles erupt? Is there a soil substrate mixed, in place? Are they using a liquid plant supplement?
Foodwise, I'd skip the bloodworms entirely and the blanched vegetables for now.
I too suspect the cause of these losses as environmental, perhaps with a genetic component.
BobF>
Re: Corydoras slowly dying off one by one, no one has answers.      4/27/20
Hello! I apologize for not responding sooner, I did not see that you had posted a response until today.
<Curious; you should have received a copy of my response in your email box.
Maybe check the spam folder?>
First I'll answer the questions and concerns that were brought up.
<Cool.>
To begin, the water movement. There's a good amount of flow all throughout the tank. All of the plants in the tank sway gently from the water current, including the low laying plants and their roots. Sinking foods roll around across the substrate during feeding times.
<Good.>
Sometimes I feel like it's too much flow! But I decided to do the flake test anyway as you suggested. I tried it out in several spots, and the results were about the same. Most of it was immediately whisked up by the
current, and the pieces that did stay on the bottom flapped and rolled around. That is, until the Cories ate them.
<All sounds fine.>
I also have both a sponge filter and an airstone going at a strong pace, so there's plenty of oxygen. They do surface for air on occasion, but I wouldn't consider it excessive at all. I'd say maybe 1-3 of them out of the
16 total will surface in the period of an hour.
<Normal.>
And they don't stay at the surface either, they dart up for a quick gulp and then right back down.
<Good.>
For the substrate, it's CaribSea Peace River gravel. I actually have Black Diamond Blasting Sand purchased because I want to switch it out, I find the gravel ugly and my Cories will appreciate sand.
<Blasting sounds like sharp sand. I'd be leery of using that with any bottom-dwelling fish.>
But I've been worried about the stress it would cause them. If you think it would be beneficial to do it now, I will go ahead and switch it next weekend. There isn't any dirt, root tabs, or anything else in the
substrate. I never see gas bubbles, and the substrate is pretty thin. (I didn't buy enough originally, part of why I want to change it.) I do use Aquarium Co-op Easygreen liquid Fertilizer, but my Cories were having
issues even during periods when I didn't use it. I've also never heard of anyone having a problem with fish related to this fertilizer, it's a pretty mild fertilizer. No copper in it or anything. I might stop using it
temporarily though just as a hail Mary.
<Understood, and a wise approach. Plants will go months without fertiliser, and even switching off CO2 fertilisation, if used, can be useful if you're trying to figure out an underlying fish health problem.>
My test kit is the API Freshwater Master Test Kit. 2 years off from expiring. I've previously checked it using my tap water and test strips to compare, and it seems to be accurate.
I was surprised to hear that my water is too warm for the Peppered Cories.
Most resources seem to point to 78 degrees as the maximum temperature they can be at.
<Maximum, sure; but bear in mind that's a range, and in the wild they're be experiencing much cooler winters. They're a subtropical, not tropical, fish, from a more southerly part of South America than the usual Corydoras species we keep as pets. While they're extremely tough, if you're having health problems, it makes sense to ask yourself: Am I doing anything to them that isn't within their normal tolerances? Might be temperature, water chemistry, even diet.>
But the Peppered Cories haven't had any problems at all. I also should have clarified, it only reaches 76 during the hottest months of the year, when the ambient temperature in the house goes up. It's at 74 degrees for the majority of the year.
<Understood.>
One weird new thing, I've noticed all of my fish (not just the Bronze Cories) have been flashing on occasion. Not exclusively, but I usually never see that behavior, so it's odd. Only change to the tank is that I
added a piece of Mopani driftwood in last week. It was boiled, allowed to dry, soaked for several weeks, and allowed to dry again before being added.
Hasn't leached much tannins at all and hasn't really changed the pH. All tests came out normal, in the range I described in my first post. I've never seen it in the previously sick Cories either.
<If the Mopani is from a reputable source, i.e., an aquarium shop, it should be fine. Bogwood bought off eBay tends to be a bit hit-and-miss, though. Collecting your own wood, while do-able (I certainly do use locally
collected wood at times) always carries a risk. If in doubt, remove.>
I'll increase the oxygen and do a large water change today, just in case.
This is so frustrating. It feels like the more I care about this tank, the more time and attention I give it, the worse things get. I do so much research, I love helping others who have problems or questions. But when it comes to my own tank I feel like a complete failure.
<Sometimes, I suggest to people they just accept certain fish species don't work for them. It might be their tank size, their local water, the way they maintain the tank. Who knows? But whatever. If one Corydoras species does fine for you, but the other doesn't, then don't bother keeping the difficult ones. If midwater fish are happy as Larry, but the catfish are struggling, then maybe don't bother keeping catfish for now. I know that isn't a very satisfying answer, but fishkeeping isn't a competitive sport, and if it isn't fun, what's the point? The alternative is this: Strip the tank down to bare basics. Remove everything but clean washed gravel, the filter, the water, and the fish. Perhaps a few floating plants or plastic ornaments for shade. But basically a bare-bones system. See what happens now. Remove anything messy, stir and clean the gravel, optimise the filter.
Leave it running a few days or weeks. Do the fish look better now? Then start rebuilding the tank you want, but using new rocks, wood, and plants -- or at least being a lot more selective about what you add, to minimise the risk of contamination. Ask yourself each time you put something in the tank: does this look safe? Rocks can have metal seams, bogwood can be decaying. Plants are usually fine, and while they don't like being uprooted to a bucket of water for a few days, they should survive.>
- Adam
<Cheers, Neale.>

 

Cory lump     9/22/19 Hi can you tell me what this lump is and how to treat? I’ve had him for 2 years. The only change to the tank is I bought a new plant about a month ago and found one snail from the plant. Water perimeters are good. It’s a 20g tall tank with live plants. I feed every 3 days. I have lava rock and a sponge filter on the intake. I do a 50% water change monthly. I have a gourami and a rubber lip Pleco and some shrimp. All other fish are ok besides the Cory. Thanks Kelly <Hi Kelly. This may be a blister, may be a tumour. Hard to say from these photos, or really, from anything short of a thorough examination. Blisters tend to be associated with reddish bacterial infections and show signs of dead skin around their edges, whereas tumours often grow from deeper inside the fish, pushing outwards, but otherwise have the colouration of the surrounding skin unless actually so large they're stretching the skin. Blisters are caused by a variety of things, but abrasions with coarse sediments and rocks are the most likely if on the underside of the fish. Treating as per Finrot can help, but the main thing is to fix the sediment by replacing with something more catfish friendly. Smooth lime-free sand is the ideal for Corydoras. Do also ensure there's adequate water flow along the substrate. Pop a bit of fish flake there and see if it gets shoved along briskly. If not, there's likely pockets of still or sluggish water that can stress bottom dwelling fish like Corydoras, and this in turn can manifest itself in the form of Finrot-type infections. Review, and act accordingly. Cheers, Neale.>

 

Cory Catfish with stubborn fin rot. Hi All, <Hello Lisa.> I am at my wit's end. Please help! This will be long, I'll start from the beginning. <Fire away.> I had 5 Sterbai in a 20 gallon long, moderately planted tank (Anubias and java fern) with soft, fine play sand substrate. It's got a nice piece of Mopani driftwood they like to sniffle on. It has 2 large sponge filters and an air stone. No CO2. I later added a small water pump and they like to swim in the flow sometimes. I got them in April 2019, online, shipped from a reputable seller. Right out of the box they were healthy and eating and sniffling around. They lived alone, just the 5 of them. I did water changes of 50% once a week, with sand vac. They get Fluval Bug Bites, Omega One Shrimp Pellets, and maybe once a week a mix of frozen bloodworms, daphnia, and brine shrimp. <All sounds fine.> Around mid-late May, I noticed 2 or 3 of them were missing little bits of their fins. No fuzz or white stuff, no blackening of the ends of the fins, no redness or irritation, just missing bits. I "medicated" with Melafix for about 5 days. No change. I medicated with 2 days worth of Kanaplex. I waited a few days for improvement, there was very little to none. I noticed one fish had it worse off than the rest, I spot-treated him with Methylene Blue a few times, no improvement (but! no staining on his tail?! So he's got intact slime coat), and within a few days it had gotten worse. Meanwhile, for about 8-10 days I did 50% water changes every other day. Still slowly worsening. Mind you, every fish is eating and swimming and playing in the bubbles, perfectly normal behavior. I remove the one fish, I'll call him Stubby. His tail was slowly but surely disappearing, and it looked like a little "chip" was taken out of his dorsal fin. I put him in a 10 gallon hospital tank on 06/26/19. This tank has a very thin layer of play sand and I put in a few mesh tunnels and some almond leaves for him to hide in. A day later I caught another fish (Chuck) that had dorsal and tail fin damage as well, not as bad, but it was there. <The wounds look clean and uninfected, which seems to rule out Finrot. Indeed, the holes in the fins look a lot more like what you see on wild catfish that have been victims of attacks by fin-biting predators.> I proceeded to medicate with Methylene Blue in the tank for 5 days, following the instructions on the bottle. No improvement in Stubby, Chuck might be getting better, hard to tell. They are very shy and run when the camera comes by. <Not unusual, especially if the Corydoras group is rather small. We usually recommend 6 or more, and in the wild, groups may number in the hundreds. It's hard to replicate that in home aquaria, but certainly the more specimens, the happier they'll be.> From then on, I have been changing water every day, still 50%. Stubby seems to have gotten a tiny bit worse, while Chuck is almost healed. They have now been in the hospital tank for 16 days. <Understood.> Hospital tank parameters: 77 degrees F., PH 8, ammonia 0, nitrite 0, nitrates 0. I do have 1 sponge filter and one box filter in there, both cycled. I keep the tank covered on 3 sides with a brown towel to keep them calm. No lights except when I do water change (desk lamp). I still do 50% water changes every day with sand vac. I make tea from Indian almond leaves, alder cones, and rooibos tea and add it every change. The water is a medium tea color. The fish, although understandably very shy, eat, sniffle around, and swim (when I'm not looking). <Water chemistry sounds a bit on the alkaline side, though it's hard to imagine a pH of 8 causing the symptoms seen here. Similarly, while Corydoras sterbai is a bit of a hothouse flower, with 28 C/82 F usually recommended, 25 C/77 F is the bottom end of their range, and should be tolerated reasonably well. So while I'd suggest kicking up the heater a notch, I can't see why lack of heat would be causing what you're seeing here.> I checked the 20 long where the other 3 Sterbai are, and yet ANOTHER fish has a little bit missing from his tail! <It certainly sounds like physical damage. Are there no tankmates with these fish? An over powerful filter might have the same effect, but you mention a sponge filter, didn't you?> I give up! I don't know what to do for Stubby, or any of them, really. I have asked in other places where to go from here, but I've only been told "water changes, water changes!" Obviously, it's not doing the trick! Kanaplex didn't work, MB didn't work...where do I go from here? What medication can I use next? <Assuming the fish are active, feeding, and growing, I would not continually medicate, certainly not until it becomes clearer what the problem is. If the wounds are clean, with no signs of Finrot (e.g., pink/white areas around the wounds) or fungus, I'd actually not medicate at all. In the wild fish routinely deal with bites and damage to their fins, and it's not a life-threatening situation at all. I'd perhaps move the whole group to a bare-bottomed tank (just in case the sand is sharper than you think) so that they can convalesce together in a dark, shady hospital tank with ideal water conditions. Some flowerpots or similar for shelter would be fine. I'd provide a bit of extra warmth, too.> I don't want to bomb them with too many meds but this has been going on too long without improvement for me to just leave it. Chuck seems much better, but I hate to take out Stubby's companion. I know they don't like to be alone. Should I just put them back in the 20 long and medicate that whole tank like I did in the beginning? What med should I use now? I'm at a loss, please help. <In honesty, I can't see any obvious reason for what you're seeing here beyond fin-biting. It's interesting that only the tail fins are damaged, while the whiskers look fine, and it's the whiskers that tend to go first if the substrate is 'bad' in some way. All very curious.> Pictures are hard to get but I have included some of Stubby. Many thanks for any help and advice you can provide, Lisa PS: I have another 20 long with adult albino aeneus, albino fry, and trilineatus Cory catfish and there's no fin rot, same substrate, same water change schedule, and they spawn regularly. Temp 76-77F. <Hope this helps, Neale.>

Re: Cory Catfish with stubborn fin rot.     8/2/19 Hi Neale, A lot has happened since I received your answer, which is why you have not heard from me in so long. I very much appreciate your reply! <Most welcome.> I am afraid that "Stubby" is slightly worse. I have moved my albino aeneus (+ 5 fry) and trilineatus to a new 40 gallon (total 9 adults). I then moved the sterbai (and 3 harlequin rasboras, fry I found when rehoming the adults a few months ago) out of the hospital tank and into the old albino tank, where the former occupants prospered and spawned. Temp is 78-80F. I broke down the old sterbai tank. At one point I was planning to put all the catfish in the 40 (albino, trilineatus, and the sterbai) but because of temperature differences I guess I should keep them separate? The sterbai don't seem very active although they do eat fine, and I believe I have 2 ladies because they are getting chubby. They are not too lively though, and I feel they must be bored with only the 5 of them. I'm afraid to get more because I don't want this problem, whatever it is, to spread to any new fish. If I put the sterbai in the 40, would they benefit from having a bunch of buddies, despite the temperature difference? I keep the 40 gallon at 76F. During the summer though, it can get up to 78F. <Do add an airstone, and be sure the water level is low enough they can easily swim to the surface to gulp air; generally, Corydoras shouldn't be kept in depths greater than 30 cm/12 inches, and ideally less.> I am still keeping them partially covered but have stopped changing water every day thinking that maybe it's stressing them out more. <Possibly, but weekly water changes should be maintained.> I did 2 days of Furan-2, but had to stop treatment because one of the fish stopped eating and was hiding. I did water changes, ran carbon, and he's fine now. I guess the medication was too strong. <Possibly, but antibiotics shouldn't really affect fish in any harmful way.> I now change the water every 5 days, although they've only been in their new tank about 10 days. Plus, we had a 4 day power outage last week, so they ran on a single sponge and water changes every other day. I can't win with these fish! I have sent two new photos, the best I could get...Stubby is slightly worse. I think Chuck must be better because I can't figure out which one he is now. Their new tank has a Tidal 35 hob and 1 large sponge filter. The hob is pretty gentle, and the albinos and 3lines never had a problem with it. I have the 3 rasboras, but they love to peck at each other and never bother the catfish. They've been moved around a few times and have lived with the albinos before the sterbai and were never a problem, not even the 9 adults I used to have. I know the rasboras need buddies or rehoming. I think I'll probably try to find them a new home. It is very weird :/ I always make sure everybody has their barbels and that they're long and pointy. <Good.> There is no whisker damage on any of the sterbai. I can't think of anything else I can do except to put them in the 40 with more friends, or get more sterbai and put them in the 20. I thank you very much for your help and patience! I'm so in love with these catfish, I want them to have the best lives I can give them. I have included 2 new photos of Stubby. I apologize for the bad quality of the latest pic, I am keeping them with low lighting for now. -Lisa <Hard to tell the colours of the fish because of the low light, but do see the fin damage. I'm wondering about Red Blotch disease, a bacterial disease that can plague Corydoras, particularly newly imported (i.e., stressed) ones. Tetracycline or Minocycline are usually used to treat this, with varying degrees of success. Nonetheless, provided the fin damage on 'Stubby' is clear, without evidence of decomposing tissue (off-white) or congested blood vessels (orange or pink) then I'd not worry too much about his fins. Clean fin damage should heal, given time. Cheers, Neale.>

 

Cory’s      6/5/19
My female Cory has a yellow spot on her top fin, she has always been very active, and still is, what could it be
<Hi, could be many things, can you please send us a pic?... will be far easier to id the problem. Wil.>

 

Corydoras has tumors     4/8/19 To Whom it May Concern: <Hello,> I have a Corydoras that looks like it has multiple tumors. There are more around its topside and one on a fin. Some of the Cory's fins are split, but there are no fungus-like films growing and it is eating and swimming normally. All my other fish seem fine, even my ghost shrimp. I have been trying to take a picture but the Cory is camera shy. :-/ <Understood.> What is going on? <Very difficult to say. Benign tumours crop up in fish for a variety of reasons, including exposure to toxic chemicals (particularly in the substrate) and certain viruses (notoriously, Lymphocystis). Benign tumours are impossible to treat, but the viral ones in particular sometimes clear up by themselves, though this can take months/years. Provided such tumours aren't obstructing important tissues or organs, they aren't life-threatening. Malign tumours do occur in fish, for a varied reasons as they do in humans, and again, aren't really treatable. A few diseases might be mistaken for tumours, such as Fish or Carp Pox, Gas Bubble Disease (usually caused by over-saturating the water with oxygen), and Dropsy. So it's worth researching these and comparing them with your fish.> What do I do? <The short answer is a to judge quality of life while providing the best possible living conditions. If the fish is not distressed, tumours are unlikely to spread, so such fish can be left alone in the fish tank. A varied (vitamin-rich!) diet, clean substrate, and good water quality can help promote recovery. If the fish is distressed, then euthanising the fish may be the best thing to do. Removal of tumours isn't really practical for small fish, thought it can be done by vets under some circumstances, and may be an option with large and valuable fish, such as Koi.> Thanks for all your help! Kris <Most welcome, Neale.> Re: Corydoras has tumors     4/8/19 Thanks for your help! I got a picture, finally. I don’t know if this changes anything about your prognosis. Sorry, the picture is a bit out of focus. <Indeed; not entirely sure what I'm meant to see. Do you mean the swelling between the eye and the dorsal fin? Where the black and white spotted skin seems to bulge outwards? Definitely that looks like a subdermal tumour of some sort. Could be benign, could be malign, but impossible to say. Unlikely to be contagious though, so no real problem leaving this catfish in with the others.> Have a great Sunday! <Alas, 'tis Monday already.> Kris <Cheers, Neale.>

Panda Cory's tail    1/3/19
Hello, I've had a panda Cory for about a year and about a week ago I got two more.
<They are social, so groups of 5+ please!>
When I cleaned my tank yesterday I noticed one of the new ones was missing his tail. This morning I saw the other new one was missing about half of his. I do believe it's due to being nipped by my sword tail.
<Or some other nippy fish, yes.
I have separated him out.
<Isolating a Corydoras (or any other schooling fish) from its compatriots can cause problems. Much better to remove the nippy fish/fishes, since nipped fins grow back fine, if left alone.>
My question is there anything I can do to help their tails grow back?
<Remove the nippy fish. Damaged fins will heal quickly in clean water.
Medication usually not required. Finrot and fungus can happen, but usually indicate a more serious problem, e.g., non-zero ammonia and nitrite levels.>
Thank you. Amanda
<Welcome. Neale.>

 

Corydoras Keep Dying      12/12/18
Good Morning!
Long time reader, first time writer. :)
<Welcome!>
I have a 40 gallon breeder that can't seem to keep cories alive. I've lost small batches of sterbai (5) and bronze (6), and now I'm afraid I'm going down the same road with pandas (started with 12, down to 10). Other fish seem unaffected, and a common symptom appears to be air/gas in intestines.
Am I missing something?
<Likely, so...>
The tank:
40 gallon breeder, 36" x 18" footprint, black blasting sand substrate (well rinsed), temp was at 79-80 for the sterbai/bronze, close to 76-77 for the pandas.
I have a cascade 700 canister filter and 2 sponge filters.
Livestock at this time includes the 10 pandas and 2 Apisto borellii (1-1.5"). Nothing else.
Some hardy plants, a few driftwoods, and some IAL and oak leaves.
<Whence came the pieces of driftwood? If purchased, are you quite sure these are "aquarium safe?" Many sold for reptiles are not safe for aquariums. If acquired from the great outdoors, how did you cure/prep the pieces? At this point in your story, I suspect the driftwood, but I will read on...>
Timing:
Started the tank in mid Sept, with half a dozen small pentazona barbs.
Cycled tank with media from another filter.
On Halloween, I added 5x 1" sterbai cories. The following Friday (2 days later), in the afternoon, 2 were floating upside down, then 2 more shortly after. Those 4 died within hours, 1 survived.
<Yikes! Something is seriously wrong here. How did you introduce them to the system? Did you acclimate them to the new water conditions? Did you test the water from the pet fish shop?>
I know everyone reaches for sbd in situations like this, but I autopsied 3 of the dead fish,
<?!?>
and the intestines were full of air.
<Well, yeah! There is this thing that happens after an organism dies. The resident bacteria have a blitz and produce gases as they ravenously digest their now deceased host. It will happen to you too some day, and to me.>
Some food (not much), but intestines were full like those long balloons clowns make shapes from. No other symptoms.
<...that you could see or recognize with the "naked eye.">
Granted, they're small fish, and seeing anything can be hard.
<If you intend to continue filleting your deceased pet fish, I highly recommend investing in a good microscope. Much to be seen can't be seen without one.>
The lone survivor (which also had buoyancy issues, but never to the point of floating/dying) was quarantined for 4-5 days (no meds, since no diagnosis),
<A good policy>
and seemed to stabilize. But 3d after being returned to the main tank, it also died,
<Interesting>
and again it appeared full of air. I should note that the autopsies were done shortly after death, and all of the sick fish were very buoyant before they died
<This can happen for any number of reasons. It is a very non-specific symptom - a sure indicator of poor fish health, but with a lengthy differential diagnosis.>
(i.e. I don't believe the gas in intestines was a post-mortem symptom).
<Impossible to know for sure either way.>
Through all this, the pentazonas were fine. Ammo/nitrite were 0, nitrates were 5-10.
<Ok>
On Nov 6 I added half doz bronze cories (I admit to getting them as coal mine canaries; clearly this tank can support fish, but can it support cories?). All 6 died one by one over a 2-3 week period. No outward
symptoms (well, except dying). Frustrating. And they had started off so well in my tank, foraging deep in the sand, very active. These did not float when they died.
Through all this the pentazonas were fine. Again, parameters good.
I rehomed the pentazonas to a new office tank, and the tank stayed empty for about a week.
Then on Dec 4 I got a dozen 0.75-1" panda cories, added them, along with a M/F Apisto borellii.
<That is a lot of fish to add all at once.>
They seem to be great tank mates, same pace, feeding rate, temperament etc.
All has been good until last night (Dec 11), when 1 was floating (air in intestines again), and another this am (didn't check). As of Sunday when I did a whack of testing, parameters generally good; ammonia was over zero,
<Yeah mate, I think you added too much too quickly to a "dormant" system.>
but under 0.25 (I've been feeding liberally, though, so that might be it.
<Yes, that too will do it. I would stop feeding for a few days at least.>
I dosed with Prime, haven't re-checked yet), zero nitrites, nitrates under 20.
<Prime is a one-time "band-aid" type fix. It binds the nitrogen cycle products so that these get taken up in the filter. If you don't keep adding it, the problem will return unless corrected some other way.>
Other pertinent:
I feed good quality food, and lots of variety. Thawed bloodworm, mysis shrimplets, bbs. Crushed Spirulina flake, regular community flake, Hikari mini wafers, Fluval bug bites.
<Maybe too much though?>
My tap water is moderately hard, so I have been mixing the water for this tank with RO/DI at about 3:2 (RO: tap). That's giving me dGH of 5-6 (100ppm), and dKH of ~4 (~75ppm). My pH remains around 7.5 (hard to tell, since it always appears to lie right between the high end of the normal pH test, and the low end of the high range pH test).
I'm using a perpetual drip and overflow to keep new water running through tank, rate of about 1.5g new water per day. And I vac as necessary.
<As necessary? How often is that?>
In summary:
Why do mid level fish appear to remain healthy and fine, while bottom dwelling cories are dying?
<Very different species have very different sensitivities, ability to tolerate physical and/or physiological insults. I suspect the problem here to be either trauma from transport/introduction or a toxin coming from
somewhere as of yet unknown. Do see other similar recent queries here:
http://www.wetwebmedia.com/FWSubWebIndex/CoryDisF4.htm >
Are there any diseases/infections/conditions that are known to cause gas in the intestines as a primary symptom, i.e. not post-mortem?
<Again, floating and bloating is just too common a symptom - like headaches and nausea in humans - could be from anything!>
Any suggested interventions? Shelled peas? Epsom salt in tank, or as bath?
<Do read other query answers in the link above. I suggest removing the driftwood, adding carbon, looking for other potential sources of toxins... also be sure to follow good acclimation protocol.>
Many thanks for your time and consideration!
<My pleasure.>
D
<Cheers Sara L>
Ontario, Canada
Re: Cories keep dying      12/14/18
Good Morning,
<Buenos dias>
So fast with the reply, thank you!!
You've focused in on a few things I did not think are important, and aren't placing much weight on things I've been clinging to. Which is why I have asked the experts!
<Haha, wait, who told you we are experts?>
To put me straight, so to speak. :)
The driftwood: 1 large piece, collected from a local headwater stream (no ag runoff or pollutants).
<Yeah, right... that you know of or that has been reported/documented.>
There are brook trout in this stream (maybe other tiny fish?). The wood was allowed to dry for about 6 weeks, then boiled for 20 min.s. In any event, I'm more than happy to remove all possible problems,
<I do strongly suggest you remove the piece collected locally. It's just too much of an unknown and a likely source of something troublesome. Even if it is not a toxin from runoff/pollutants per se, there could be something else (some tannins maybe) leaching out of it.>
and work from there, so I'll pull it out tonight. There are also a couple of smaller pieces I got from a local aquascaper, vine wood he imported by the crate, and it's used in many tanks by many local keepers.
<If removal of the large local piece doesn't solve the problem, I would remove smaller ones these next.>
Carbon: Great suggestion, I missed that. It will go in tonight.
<Never really hurts and often helps!>
Acclimation: floated sealed bag for 20 min.s, then add small amounts of tank water over 1hr (pour out half of mixed water half way through), then add fish to tank via net
<Nets are terrible (too much risk of injury with them getting stuck/tangled). Personally, I avoid them whenever possible. In my opinion, it's better to scoop them out gently by hand than with a net, or just pour them out with the last little bit of bag water.>
without any store water. But deaths have all occurred after at least 2 days, and now upwards of a week - is that consistent with insufficient acclimation time?
<Based on the technique you described, no, I doubt acclimation was the problem. As for how injury from poor acclimation might manifest in the fish, that can vary greatly.>
I've never found an answer to this.
Store water: not tested, but I believe it has similar pH and hardness to this tank. Regionally, our water is quite similar from one municipality to another (medium hard, well buffered). It's definitely not polar opposites.
Dormant tank: during the week the tank was dormant (before I added the 12 pandas and 2 Apistos), I kept feeding the tank with crushed flake (using the same amount as I had been feeding when it had fish).
Adding too many fish: In my own defence, the tank/filter was still cycled when I added the fish, the cories and Apistos are all very small, and for the bioload, it's a big tank. I haven't been testing daily, but none of the fish (past or current) showed any signs of irritation/stress like gasping, flashing, hiding, pumping gills, and so on.
<Ok>
Vac "as necessary": I keep my tanks pretty clean. Most have sand substrates, which require less maint than gravel. I vac when there is visible detritus in areas with less flow. At any rate, I never go more than
2 weeks between vacs, and "water changes" are constant with the drip through system.
Prime for low ammonia reading: I know this is a 24-48hr band aid, and if the source of ammonia, or lack of processing ability aren't addressed, the problem persists.
Rate of feeding: I'm generally conservative when feeding my tanks, but I have a soft spot (fear spot) for new fish. Cories are such casual feeders, I'm fearful that the 30 second or 2 minute rule won't give enough food.
<Do reduce your feeding. Fish do not need as much food as people tend to think they do. Also, they can go a very long time (we're talking weeks) without any food at all.>
Even with the filter off, some foods don't even settle to the bottom in that time. When I listed all the foods I feed, I should be clear that it's not all at once. One at a time only. For flakes or other dry food, a
smaller-than-medium thumb-and-one-finger pinch is all. For frozen foods, less than half a cube of bloodworm, or maybe a quarter of a portion of mysis. At any rate, I'll fast the tank for 48hrs, dial back the feeding after that, and monitor ammonia carefully.
<I think if you remove the drift wood and add carbon, you will likely see an increase in your Cory survival rate.>
Cheers,
David
<Good luck! - SaraL>
Re: Cories keep dying      12/14/18
Thanks again, Sara. Driftwood out. Carbon in. No food. I'll keep an eye on things.
<Great. Do start feeding again in a couple of days though. :-)>
Also of note: Like many fish folk, I rarely test except when something is wrong (that I can see or sense). But with this tank, I've been keeping on top of parameters a bit more diligently, given the problems I've had.
<It's always a good idea to test every once in awhile, problems or no problems.>
I mentioned in a prior email that I am seeing trace ammonia. I've had a chance to check other tanks and tap water, and I'm getting a trace reading across the board. Best match for colors is between <0.25ppm for tap and other tanks, and >0.25ppm for the Cory tank. Even my RO/DI is testing at >0ppm. So I'll look into an ammonia removing media for the filter, and continue to use Prime and monitor.
<Sounds like a reasonable plan.>
Cheers,
David
<Cheers, Sara L>

Undecided about how to treat further     10/18/18
Hi crew!
I originally added 7 peppered Corydoras to a filtered and cycled quarantine tank. They have been in there for almost two weeks (I plan on quarantining for 4 weeks).
I purchased them from a local chain fish store. They told me that they had been treated with Quick Cure for about a day while in display tank.
<Mmm; the ingredients are too harsh (formalin, Malachite Green) for Corydoras, most catfishes>
My tank parameters are 0 ppm ammonia and nitrite, 5 ppm nitrate, pH 6.8, temp 76°F, Aquaclear filter and airstone, sand substrate, driftwood and wood stone.
<Sounds good>
I lost two corys the second day after I added them to my quarantine tank. I did carefully acclimate them and they didn't seem stressed afterwards. I don't normally add medication to the tank unless I notice a problem. The second morning one of the corys had severe pop eye in both eyes. Eyes were not cloudy but were severely swollen, one eye had actually ruptured.
<?! What happened here? Something/s very wrong... too much difference twixt the waters? The fish too long in the bag, overheated...? Some source of overt poisoning? I'd removed the driftwood, add activated carbon to your filtration>
A second Cory had mild pop eye in both eyes and a third was on its side breathing rapidly (no pop eye). The Cory with the severe pop eye died that morning as did the one on its side with respiratory issues. I did a small 15% water change (parameters were normal) and dosed the tank with Kanaplex. I did a full three dose course of Kanaplex, then 48 hours after the last dose did another water change (25%) and have basically just been observing for further symptoms. The Cory with the mild case of pop eye recovered completely and up until today everyone has been eating and acting normal. I did have one that was away from the group quite a bit and not as active but still coming out to eat.
This evening when I got home, one of my corys (I believe the less robust Cory) was basically floating near the surface; still alive, he will swim a bit when nudged, but not looking well. No sign of hemorrhage under skin, body normal with good slime coat, fins and barbels normal, respiration normal but extremely lethargic and just floating at surface. Upon inspection he looks perfectly normal. The remaining 4 corys are eating and acting normal.
I do have Metroplex on hand as well as General Cure. Do you think I should try adding Metroplex to the water column or food?
<I would not. Metronidazole has specific uses. Unless you/I can detect the organisms involved (if any; which considering the rapid onset...) I would not treat>
I do a water change every 5 days (tomorrow is 5th day) but even though I match pH and hardness and temp, I'm afraid a water change will push the sick Cory over the edge. Although the antibiotic appeared to resolve the original problem, I don't want to repeatedly dose the tank. I'm wondering if there could be an underlying parasitic problem (gill fluke?). None of the corys look emaciated and even the sickly one has a normally rounded belly. Any suggestions?
Thanks crew!
Sue
<Corydoras paleatus is a hugely aquacultured species of long use; quite labile in its placement, range of conditions. Again, I suspect either trauma or toxicity at fault here. Would just remove the driftwood, add carbon... Bob Fenner>
Undecided about how to treat further     /Neale     10/21/18
Hi crew!
I originally added 7 peppered Corydoras to a filtered and cycled quarantine tank. They have been in there for almost two weeks (I plan on quarantining for 4 weeks).
I purchased them from a local chain fish store. They told me that they had been treated with Quick Cure for about a day while in display tank.
My tank parameters are 0 ppm ammonia and nitrite, 5 ppm nitrate, pH 6.8, temp 76°F, Aquaclear filter and airstone, sand substrate, driftwood and wood stone.
I lost two Corys the second day after I added them to my quarantine tank. I did carefully acclimate them and they didn't seem stressed afterwards. I don't normally add medication to the tank unless I notice a problem. The second morning one of the Corys had severe pop eye in both eyes. Eyes were not cloudy but were severely swollen, one eye had actually ruptured. A second Cory had mild pop eye in both eyes and a third was on its side breathing rapidly (no pop eye). The Cory with the severe pop eye died that morning as did the one on its side with respiratory issues. I did a small 15% water change (parameters were normal) and dosed the tank with Kanaplex. I did a full three dose course of Kanaplex, then 48 hours after the last dose did another water change (25%) and have basically just been observing for further symptoms. The Cory with the mild case of pop eye recovered completely and up until today everyone has been eating and acting normal. I did have one that was away from the group quite a bit and not as active but still coming out to eat.
This evening when I got home, one of my Corys (I believe the less robust Cory) was basically floating near the surface; still alive, he will swim a bit when nudged, but not looking well. No sign of hemorrhage under skin, body normal with good slime coat, fins and barbels normal, respiration normal but extremely lethargic and just floating at surface. Upon inspection he looks perfectly normal. The remaining 4 Corys are eating and acting normal.
I do have Metroplex on hand as well as General Cure. Do you think I should try adding Metroplex to the water column or food? I do a water change every 5 days (tomorrow is 5th day) but even though I match pH and hardness and temp, I'm afraid a water change will push the sick Cory over the edge. Although the antibiotic appeared to resolve the original problem, I don't want to repeatedly dose the tank. I'm wondering if there could be an underlying parasitic problem (gill fluke?). None of the Corys look emaciated and even the sickly one has a normally rounded belly. Any suggestions?
Thanks crew!
Sue
<Hello Sue. One possibility is your Corydoras have been struck by something called 'Red Blotch Disease', likely similar to your standard issue Aeromonas and Pseudomonas infections that cause Finrot. It seems to be related to the stress caused by shortcomings in the environment, so rather than catchy per se, it's something several catfish might exhibit because they've all been stressed. When Red Blotch Disease was first described, it was usually associated with imported catfish that had been shipped in less that perfect conditions or held in overstocked tanks. Today you're most likely to see farmed or tank-bred Corydoras, but it's still possible for catfish to be kept in ways that cause them stress. Now, while the problem is bacterial, if the underlying triggering factors in the environment aren't fixed, antibiotics won't help. So while something like Tetracycline or Minocycline should help, let's recap the fundamentals. Almost all Corydoras prefer cooler water with plenty of oxygen -- exceptions including Corydoras sterbai and the Brochis species -- but certainly your common species like Bronze, Peppered, Panda, and Leopard Corydoras will all be best kept between 22-25 C/72-77 F. Another key thing is that the substrate should be both clean and soft. What I mean here is that the surface should be regularly siphoned to remove organic muck, with the top 1 cm or so being stirred beforehand to remove anything buried inside it. The substrate should be soft sand, smooth silica sand being ideal. Sharp sand and coarse gravel abrade catfish as they try to dig, making Red Blotch Disease more probable. One sign the substrate is 'wrong' is to look at the whiskers -- if they're short and rounded, then the gravel or sand is too sharp or too dirty. Since your catfish are newly bought, the problems might have been in the retailer's tank. That being the case, a clean tank plus suitable antibiotic should fix things if that's possible. I wouldn't randomly treat for flukes, worms or some other type of parasite because the symptoms sound so generic that an opportunistic bacterial infection strikes me as more likely. Cheers, Neale.>
Re: Undecided about how to treat further      10/21/18
Thanks Neale.
<You're welcome.>
I did lose the one Cory who was hanging out at the surface. Barbels and fins look good on remaining Corys.
<A good sign.>
The survivors are eating and acting normal.
<Likewise.>
I'm doing small water changes every few days.
<Wise.>
My substrate is sand and temp is around 76°F.
<Might lower the temperature a bit, certainly if these are Peppered Corydoras or one of the other cooler clime species. 22-24 C/72-75 F is probably optimal for most Corydoras, even if they tolerate water that's a little warmer. Certainly, adding extra oxygen can help, especially if your specimens are making frequent dashes to the surface for air -- a good sign the catfish are either heat-stressed or the bottom layer of water is oxygen poor.>
I think I have good surface agitation with AquaClear HOB and additional air stone.
<Good.>
You observation that it's stress related is the most likely cause of my losses. The LFS transfers them directly from shipping box to display tank and I found out that I had picked them up the same day that they came in. Poor fish!
<Ah, yes, this sounds like a bad situation.>
The remaining 4 (I lost three) are looking good and eating. I'll continue to keep their environment clean and stress free and keep my fingers crossed.
<Most Corydoras species are reasonably hardy, and some, like Peppered and Bronze Corydoras, a fair degree tougher than that. Good conditions, and perhaps suitable antibiotics, should help, given time enough for the fish to feed up and put on weight. Good luck! Neale.>

 

Corys       6/3/18 Hi there, Wondered if you could help, one of my corys has developed a large cyst on its eye. It’s completely over the eye. <Yowsers! That's quite the blister or cyst. Could be either, really. These are hard to treat satisfactorily, and prevention is really the thing to focus on. Corydoras are burrowing fish, and gravel isn't ideal. It tends to abrade their skins, allowing bacterial infections. The commonest symptom of this is the absence of whiskers, which on an adult Corydoras should be several mm long and distinctly narrow and tapering at the ends. Yours very obviously has abraded whiskers, which strongly suggests the wrong environment in terms of substrate. Of course sometimes Corydoras seem to do just fine in tanks with gravel, so there does seem to be a second factor at work, likely a generally unclean substrate that fosters the wrong sort of bacterial growth. Hard to say really, but I'd encourage you to look at your tank, especially the substrate, and draw your own conclusions.> Other than the obvious, the fish is not acting any differently. Any advice? <Treating cysts and blisters is difficult. Cysts tend to be solid, whereas blisters are (as their name implies) hollow with a tissue fluid centre, so may flop about a bit when the fish moves. Antibiotics can help with blisters, but cysts do tend to be viral, and there's really nothing you can do beyond waiting for the fish to get better itself. In either case, it's really about fixing the aquarium more than anything else, because there's no one parasite or pathogen involved, and therefore no "easy" solution you can buy from the pet store.> Thank you in advance! <You're welcome, Neale.>

 

Hopefully final update on Blobby White Panda Corydoras     11/30/17
Hi Crew, back in October I wrote to you about some sick Corydoras I had in quarantine that had developed a white coating and we had a bit of to and fro on different treatments, whether to euthanise etc. Despite trying every treatment available to me I have slowly lost more and more of the Corydoras including one that didn't have any of the white patches, but whose mouth seemed to have become swollen shut by small warty or tumorous bumps.
Tonight I finally lost the last of the white bumped corys.
<Sorry to hear this.>
I still have 3 Panda Corydoras that are mostly clear, one has a white lesion on his tail which hasn't changed for weeks, the others look a bit odd around the nostrils or on their fins but seem fairly healthy.
<Understood. Would continue to keep these isolated for now.>
The 2 sterbai Corydoras that were in the same quarantine tank never showed any sign of this illness, and neither have the rasboras that are also quarantined in this tank.
<Odd, but I suppose a silver lining.>
To recap: samples I have tried to take of this white matter have resulted in scraping off a waxy substance with no details of note when viewed under the microscope.
<May simply be mucous and/or decomposing tissue, neither of which will show much under the light microscope at low powers.>
Affected fish look really terrible but have mostly had an active demeanour, eating and swimming fairly normally right up until the day they die.
With this last fish I caught him in his death throes (laying on his side and struggling to swim or orient) and decided to euthanise him since his condition was so poor and I did not expect him to get better. After netting him out he appeared to have a red lump, an abscess or tumor I guess, on his caudal peduncle which looked to have broken to the surface and might be what finally did him in.
<Agreed.>
Since, unlike the others, he had very thick bumps with strips of healthy skin in between, I became determined to try and get a good sample off him to have one last look under the microscope. Upon closer examination I saw two tiny blisters on his white bumps, which finally clued me in that these bumps are not ON the skin, they are IN the skin. Or, rather, maybe they are the skin, thickened?
<Could be either really, and without seeing the fish, impossible for me to say. The fact is that many skin infections do cause blisters just below the surface, e.g., Whitespot cysts. So in and of itself, the fact there's a thin layer of skin over a growth or cyst doesn't rule out external parasites or infections.>
The stickiness I experienced when trying to take previous samples would have just been slime coat. I tried to scrape the thickest white patch and it was much like when your hands are wet for too long and the thickest parts swell and become easily damaged.
<Understood.>
With this new information I Googled once more and almost immediately came across a page about Carp Pox (Cyprinid Herpesvirus)
https://www.koi-pond-guide.com/carp-pox.html and the picture on this site looks pretty close to the blobby lumps that
were covering my Corydoras. The description of waxy lesions and fish that remain active and with a good appetite also matched what I experienced with my fish. I don't know if corys are susceptible to this particular virus but it does seem they had something similar all along which would explain why none of the treatments I tried worked. The page lists Lymphocystis and epitheliocystis as other possibilities but none of the pictures I saw of those looked anything like what was on my corys (and I suspect the antibiotics would have treated one of those).
<Viral infections are very difficult to diagnose except perhaps in those cases, like Carp Pox, that the symptoms are well defined and familiar enough that aquarists can recognise them easily enough.>
Have you heard of Corydoras being affected by a fish herpesvirus before?
<No; it's generally regarded as quite species specific, affecting Koi, its Common Carp ancestor, Goldfish, and its closely relative the Crucian Carp.>
I do remember our government in Australia talking about releasing CHV-3 into our waterways to kill pest carp species which makes me think they are sure it doesn't cross to other species.
<Indeed; what experimental evidence I could find on this suggests that native catfish, eels, and Rainbowfish, among others, were all unaffected by the virus.>
Mistakes have been made before though - cane toads spring to mind. I can't find much more information out myself but I feel that I have finally got a satisfactory idea of what was going on. I have been pretty strict with not sharing equipment between this tank and my other tanks and now I'm wondering if the usual net-disinfectant etc and washing my hands, will be enough to prevent the spread of this virus. Any advice on this front would be appreciated!
<CSIRO feel that the virus is not going to risk Australian native fish, though that's primarily because there are no native cyprinids in Australia, so even if the virus adapted a little bit, there are simply no even halfway related carp-like fish in Australia it could mutate towards. Catfish are far too distantly related for this risk to be significant. It's a bit like how humans can get mutated versions of viruses that originally infect monkeys or apes, but generally don't get viruses that infect cats or horses.>
Anyway just thought I would pass on my findings and my suspicions that this case was some kind of viral skin infection. Perhaps in healthier or hardier fish it even may not have been fatal as it took 8 and 9 weeks to kill four
of my Corydoras. So for now I will continue to monitor this tank and keep everything isolated as before and I will continue with just clean water and good diet as the treatment.
<Indeed. Just because CHV isn't the issue here, doesn't mean a virus of some kind can't be in play. There absolutely are viruses that affect widely disparate species out there -- the DGIV virus that affects Dwarf Gouramis has also been detected in certain other species. How common this is, and how dangerous, is hard to say. One issue is that there really are so many viruses out there -- and as aquarists we can diagnose so few of them -- there almost certainly is a Corydoras virus out and about, we just don't recognise it.>
Thanks for your help!
Bronwen
<Welcome. I'd tend to put down your experiences to bad luck. Might be a virus, might not. Hard to know. I'd isolate the sickly ones for another couple weeks at least, but if the disease has otherwise 'run its course' it may have run out of species it can infect. The Rasboras can probably go into the display tank, and the Corydoras sterbai may as well, since they seem to be immune or at least not affected by the virus, bacteria or pathogen. Good luck! Neale.>

 

Corydoras panda whitens out      8/16/17 Good evening (here), WWM Crew, I hope you are having a good week. Kindly allow me to emphatically state that this hobby is so fantastically rewarding but so frustrating sometimes!!! <Oh, I concur> My tank specs are ammonia/nitrite zero, 15-gal column, <Mmm; not the better shape for Corydoras... which are facultative aerial respirators (come to the surface to breathe)> everyone looking great and getting along fine. I have three large C. metae and one small C. panda, along with my mid- and upper-dwellers... the corys get shrimp pellets at night, a few times per week. <I'd feed these (diurnal) cats during lights-on time> I try to never overfeed. This morning the panda Cory's off-white skin was bright white and he was buoyant but visibly lethargic. Worst part--I had to leave for vacation. I decided that perhaps the big boys were boxing him out for food, so maybe he was malnutritioned. I did a 25% water change and then moved the panda Cory--he did not put up much of a fight--into a floating breeder and dropped two different brands of shrimp pellets in for him. I figured if he wasn't eating, then now was his chance, and although now isolated, his stress level would have been high, regardless. <Yes> I removed most of the pellets before I left, leaving some crumbs. This way (1) ammonia from decaying small crumbs, at the top of the tank, wouldn't be too awful for the water (correct?) <Hopefully> and (2) if he still didn't make it, his body wouldn't become a meal for others. How would you have handled this one? <Moved the fish to a different, established set-up if I had one> And if this little guy does make it, do you have any ideas regarding his survival besides moving him to a new tank? <This is about it. How warm is your water?> Ideas are more than appreciated! Thanks, Matt <Welcome. Bob Fenner> Fwd: Corydoras panda whitens out      8/16/17 I meant to attach this photo: <As you stated, stressed... BobF>

Re: Corydoras panda whitens out       8/17/17 Thanks Bob. I have the tank at 74 degrees <A good temp. for all> and I did work hard to find larger corys when I got these C. metae fishes, in hopes their bigger fins could propel them more easily to the surface to gulp air. They playfully race up and down the sides so it doesn't seem like a problem for them. I don't recall reading on WWM that I should try feeding corys during the day, but I can give that a shot, then maybe I can make sure they get to the sinkers while the others eat at the surface. I'll report back after my trip. Thank you! <Thank you Matt. BobF> Re: Corydoras panda whitens out      8/21/17 Hi Bob, just following up... the panda Cory did not make it although I'm happy with my decision to keep him in the breeder so his body was not a Gourami snack. I removed him and did a 25% w/c. I'm going to see if these three large C. metae will fit the bill in this column tank... <I think they will admirably> would you say, one shrimp pellet each, a few times per week? <Yes> If not, Neale suggested whiptail cats instead. <Another good choice> They are tough to find around here so may be pricey... do you think they will survive with (smooth) gravel substrate? <Yes I do> Thank you! <Welcome. BobF>

Cory health in 15-gal column tank      5/3/17
Hello Team, I searched the archives and I can't find this one.
I was hoping for some help with Corys in my tank. I have had a 15-gallon column tank for two years, with a single Opaline Gourami, five cherry barbs for a year (three m, 2 fem), and two (avg.) non-dwarf Corys. I feed flakes and float pellets once daily, a sinking shrimp pellet every few days, and freeze-dried bloodworms once a week. My ammonia and nitrite levels are zero and my temp hovers around 77 degrees. I filter with an AquaClear 20.
<Mostly sounds fine...>
I seem to only manage to get a 6-month lifespan from my corys, regardless of the breed. This seems short; when one passes, I buy a new pair to avoid loneliness, and the cycle continues. Just today, I have a single one again. (1) should I purchase a single or a pair more corys if any, and (2) am I doing something wrong or are corys simply a bad idea in this configuration?
<Corydoras are basically sound fish, but they do have a couple weaknesses.
Firstly, they're low-end tropicals. A good temperature range for most species is 22-25 C/72-77F. Corydoras sterbai is the one widely trained warmer water species. Anyway, the warmer the water, the more oxygen they
need. This brings us to the second point, their need for air. If the tank is too deep, they can't easily swim to the top to gulp air, and this in turn leads to stress. I don't think a 15 gallon tank is likely to be too deep, but if there's something stopping them swimming, like a strong current or aggressive/nippy midwater fish, it might have an effect on them.
Finally, there's the oxygenation of the substrate. If the bottom of the tank has poor water movement, the substrate can become anaerobic, and together with microscopic scratches to their whiskers and fins, Corydoras become sickly, listless, and may well die. So short term: I'd clean the substrate, I'd check the water flow, I'd lower the water temperature, and I'd check none of the other fish are harassing them.>
I know they should be kept in larger groups but I don't want to crowd them on the small floor. Should I choose another scavenger instead?
Bristlenose catfish seem too "dirty".
<They are not messy at all, given their size; but they're also pretty rubbish scavengers, being more or less algae-consumers. I find Whiptails a much better substitution for Corydoras. Standard issue Rineloricaria species are sociable, hardy, and long-lived.>
Any insight would be greatly appreciated. Thank you for all you do!
Matt
<Hope this helps, Neale.>
Re: Cory health in 15-gal column tank      5/4/17
Great advice, thanks Neale. I think I might give the whiptail a shot, as you suggested. For this columnar tank setup, so you think I should go for one or two?
<Definitely more fun kept in groups. Males hold little territories (like a crevice in a bit of bogwood) when breeding but otherwise Rineloricaria species do seem to be sociable much of the time. Singletons can do fine though, they just aren't as much fun. Do note that Whiptails are day-active, and prefer sandy substrates where they can bury themselves in at times. They will also change colour on sandy substrates, which is very cool to see! Underrated fish, I think because they *look* delicate -- even though they're actually quite hardy animals.>
Thanks,
Matt
<Cheers, Neale.>

 

Peppered Cory Illness      7/1/16 <Am responding here for timeliness-sake, but asking Neale Monks to respond as well> Hello, I have been assisted by your staff in the past for some issues with angelfish, so I thought I might get some help with my Corys. I have the following setup: 55 Gallon Artificial Plants Driftwood Sand substrate Fluval 305 Canister Filter 5 Corys (3 Peppered and 2 Green) 5 Neon Tetras 5 BN Plecos 4 Silver Dollars 1 Male Betta Food: Crisps, algae wafers (veggie and protein) daily. Betta gets a small amount of "Betta Food Pellets". Weekly offerings are bloodworms and/or Tubifex worms. Plecos LOVE cucumbers and the silver dollars enjoy romaine lettuce leaves. I do 50% water changes every week and clean my canister filter every 2 weeks (suggested is once a month but I do tend to overfeed with the silver dollars). Two of my peppered Corys are ill. Both have turned a dark, almost, black. Listless, no eating. <Mmm; something environmental at play here... introduction of a pollutant? With the lettuce perhaps... I take it the insect larva and worms you're feeding are processed... Not live> The larger of the two (female) is at least 3" long and she's just over 6 years old. The smaller (male) is about a year old and he is the same. The female has ragged fins and the male has a "scrape" on one side of the his tail where the paler "flesh" is showing and for a day or two had a red ring around the lower half of his eye orbit. <Physical trauma? From... the Dollars? The Plecos?> That has disappeared. The only outward sign of illness I have noticed is the female had an episode of her chronic swim bladder disease. From time to time (every 6-8 months), she will float to the water's surface and end up laying on her side for part of the day. I always withhold food and within 8 hours, she's great again. This happened last week. I was unable to do my regular weekly water change last Saturday, because I had the flu. So, my parameters are as follows: pH 7.5 Nitrate: 5 Nitrite: 0 Ammonia: 0 <Water temp.?> The female is my favorite fish. She's typically happy and LOVES water changes. She is just listless and I think she may have a little spot on her forehead, but I really can't tell with the dark color. I would sincerely appreciate any advice you can offer. All the other fish in the tank are happy and acting normally. I do notice some dark-looking (dark brown) algae or slime just beginning to form on my plastic plants, but this is something that I get regularly and clean each week..... Thanks! PS - Going to attempt to get a couple of pics to send as well <Good> Kristi A. Jones <Bob Fenner> Peppered Cory Illness /Neale      7/1/16 Hello, I have been assisted by your staff in the past for some issues with angelfish, so I thought I might get some help with my Corys. I have the following setup: 55 Gallon Artificial Plants Driftwood Sand substrate Fluval 305 Canister Filter 5 Corys (3 Peppered and 2 Green) 5 Neon Tetras 5 BN Plecos 4 Silver Dollars 1 Male Betta Food: Crisps, algae wafers (veggie and protein) daily. Betta gets a small amount of "Betta Food Pellets". Weekly offerings are bloodworms and/or Tubifex worms. Plecos LOVE cucumbers and the silver dollars enjoy romaine lettuce leaves. I do 50% water changes every week and clean my canister filter every 2 weeks (suggested is once a month but I do tend to overfeed with the silver dollars). Two of my peppered Corys are ill. Both have turned a dark, almost, black. Listless, no eating. The larger of the two (female) is at least 3" long and she's just over 6 years old. The smaller (male) is about a year old and he is the same. The female has ragged fins and the male has a "scrape" on one side of the his tail where the paler "flesh" is showing and for a day or two had a red ring around the lower half of his eye orbit. That has disappeared. The only outward sign of illness I have noticed is the female had an episode of her chronic swim bladder disease. From time to time (every 6-8 months), she will float to the water's surface and end up laying on her side for part of the day. I always withhold food and within 8 hours, she's great again. This happened last week. I was unable to do my regular weekly water change last Saturday, because I had the flu. So, my parameters are as follows: pH 7.5 Nitrate: 5 Nitrite: 0 Ammonia: 0 The female is my favorite fish. She's typically happy and LOVES water changes. She is just listless and I think she may have a little spot on her forehead, but I really can't tell with the dark color. I would sincerely appreciate any advice you can offer. All the other fish in the tank are happy and acting normally. I do notice some dark-looking (dark brown) algae or slime just beginning to form on my plastic plants, but this is something that I get regularly and clean each week..... Thanks! PS - Going to attempt to get a couple of pics to send as well <<Would start by reviewing the environment, as Bob suggests. Corydoras paleatus is a low-end tropical species that can be stressed by overly warm conditions; 22 C/72 F is ideal, and if you're keeping other tropicals that like cooler water (such as Danios, Neons, Swordtails and Platies) then doing a good-sized water change with cooler water can pep the fish up. If cooling the tank isn't an option, add an airstone and/or another filter, because lack of oxygen rather than raw temperature is the thing that stresses them. Ditto more frequent water changes just to improve conditions generally. Now, reddish or whitish flecks on the fins and between the armour plates (scutes) is usually a sign of bacterial infection. Early on, the sorts of antibiotics used for Finrot can work nicely. There's something called Corydoras "Red Blotch" Disease that does plague these fish from time to time. It's probably triggered by an environmental shortcoming of some sort. I've written about the disease over at Fish Channel, here: http://www.fishchannel.com/fish-health/disease-prevention/red-blotch-disease.aspx Take a read. Hope this helps, Neale.>> Re: Peppered Cory Illness      7/1/16 THANK YOU BOTH! I took some pics at lunch. They are attached. Perhaps temperature is an issue. I had been keeping the tank at 78-80 for angels that I previously kept (gave that up - no luck with that breed of fish), and I do recall my peppers doing much better with cool water at 72-74. <Yes> Oh, if it could be that simple.....please let me know what you think. I know my tetras and Plecos do great at lower temps....I believe the silver dollars will as well. <They should; yes> The pic of my female Cory on the red gravel substrate was within the first couple of months after I adopted her from my brother. I thought this would be helpful for comparison. THIS is what I'm used to seeing with her....and the changes may be subtle, but she's very special to me. The remainder of the pictures were taken today. The fish with the skinned up tail section (last two attachments) is the little male. The rest are of my female. The torn fins could be the result of the horrible advice I received 2 months ago from my LFS when they suggested tiger barbs would be good in this tank..... wow, were they wrong. <Oh yes; too nippy> I had those guys less than 5 days and they were ravenous, BUT I don't recall seeing any of this fin damage. When I compare the two pics of my female, her eyes may look a bit enlarged? She's always had such large ones.... <Both the before and current pix eyes are indeed too large> I will definitely do a 50% water change tonight and slowly lower the temperature. <Good> I'm pretty careful with the lettuce and Cukes, but please let me know if there is a specific manner of cleaning these foods before adding to the tank. <Soak them in tap water over night before offering. DO test the soak water for nitrates... telling> I typically serve raw after about a 2 minute thorough rinse under lukewarm water. <Again; the soak> THANKS again, you folks are SO knowledgeable and it is extremely reassuring to have a source of experience to go to in these times of illness with our little finned friends. <A pleasure to share; offer aid to other aquarists, humans who would better their understanding> Kristi A. Jones <BobF>

Re: Peppered Cory Illness /Neale       7/2/16 Thank you! Will follow all suggestions and let you know how they do....just two more questions: 1. Do you see evidence of an infection in the body condition of either fish? <You can't really tell this by looking at a photo. I'd assume so, and medicate as per bacterial infection. It won't do any harm, and will help if bacteria are at play here.> 2. Do you feel the large eye issue is PopEye or is there something I need to do to that end? <Pop-eye tends to fix itself when environmental issues improve, and assuming a secondary bacterial infection doesn't set in (again, another good reason to use anti-bacterial medications). Corydoras do get a bit "bug-eyed" when stressed, but usually recover from illness well, if the problem is caught early. Epsom Salt helps Pop-eye, so again, I'd do this alongside the antibiotics, as previously discussed.> Much appreciated! <Welcome. Neale.>

 

Panda Cory Advice; hlth., sel.  (Note: divide genus...)     6/1/16
Hi Crew!
<Hello Bronwen!>
It's been a long time since I've written and I feel a lot more capable in fish keeping than when I started out, many thanks for providing such a great educational resource! I have written before asking about Corydoras and have since set up a sandy bottom 90 litre planted tank with the goal of keeping some small Corydoras - I chose Corydoras panda. I have had a few mishaps along the way, which is a long story involving Corys wasting away, failing to thrive, then an extremely fast acting and virulent Finrot that hit penguin tetras and coincided with white patches on Corys while all guppies were spared of either, and this was after no known recent change or addition to the tank. But that's in the past now, and it's not what this email is about. Currently I only have 3 panda Corys left of 10, and I would love to get this back up to a proper sized school. I'm planning to remove the guppies as I suspect they were stealing all the food before the more timid Corydoras could get their fill. Anyway I am looking for help on which is the least bad choice for me to obtain more panda cories.
<Understood.>
The first batch of 5 or 6 panda Corys I purchased online had no barbels to speak of, and some were quite thin and sickly, most of those died - I believe this store to be a possible source of the Camallanus infestation I had earlier on so I had pre-emptively wormed these fish but it didn't help.
<Sounds plausible. Certainly, fish received in this sort of condition should be quarantined for at least 4 weeks, and ideally longer. Basically, until such time as they're putting on weight and obviously repairing any previous damage.>
The next batch I purchased from elsewhere, and were a lot healthier with beautiful barbels, but they spent an extra day in the post and I believe were quite stressed from the voyage. A couple of those were thin and sickly and died too, although they lasted a fair few weeks. This second shop charges 2-3 times more per panda Cory than anywhere else I have seen. Lastly. I have seen panda Corydoras sold locally very rarely, but every single fish I have bought from the local fish store has died within the first month or so. They frequently have ich outbreaks, livestock with visible white fuzzy patches or red spots, or wounds, dead fish in display tanks and in shared sumps. I really don't want to purchase anything from there as it would mean almost guaranteed disease, and I don't want to give money to people who mistreat their fish so badly - but I do have better medication available to me than I have had previously (eSHa 2000 which saved some fish during the great Finrot disaster after I was sure I would lose every single one), and at least I'd be able to see the state of the fish before committing to buy. Ideally I don't want to be medicating Corydoras at all, I know they're sensitive.
<Yes and no. They're no more sensitive than Dwarf Cichlids or Loaches, say.
Indeed, they're probably tougher in some regards. But they do have specific weaknesses. Copper and formalin are two chemicals to avoid. On the other hand, antibiotics shouldn't cause and problems, and short-term used of low salt doses (i.e., 2 gram/litre across 10-14 days) is a safer way to treat for Ick/Whitespot than many commercial medications. Complicating things is heat stress, Corydoras mostly doing best at 22-25 C (one or two exceptions, such as Corydoras sterbai, do well above this, and a few, like Corydoras paleatus, are actually happier even cooler). Heat increases their demand for oxygen while reducing the amount of oxygen in the water, and the tendency to keep Corydoras in overstocked tanks makes the risk of heat stress even higher. Of course they will gulp air when they need to, but
that in turn makes them more likely to inhale airborne toxins such as paint fumes compared with regular fish.>
I'm really not sure which option is the least bad. If I get cheap but barbel-less fish I can buy more of them and hope to nurse them back to health. If I get expensive but healthier fish, will they recover from shipping stress better than they would recover from illness? Or are the odds that the stress would make them get ill anyway? And then also, I
wouldn't be able to buy as many and each lost fish would cost me more.
<A real conundrum, for sure. If you have a quarantine tank, then buying 2-3 at a time from the less reliable place might be worth a flutter. Each time quarantine until they're back to health, pre-emptively deworming if you think that's necessary. But if that isn't an option, getting them from the more expensive place would probably make more sense. Better to have a group of 5-6 good specimens and breed from them than to try to buy a dozen or more that simply don't survive for long.>
The local option would involve me waiting long enough for a panda Cory shipment to come in, and then buying them before they've been held in the shop for long since the longer they're there the more likely they are to get sick - which is the complete opposite of the usual method of waiting to see which new arrivals last a few weeks in the shop.
<Correct; but in this case, with the cheap place, you've got to do the quarantining.>
I haven't got a quarantine tank ready yet and I want to do that first before I buy any more Corydoras. I'm really stumped on where to get them from. Due to where I live my options are pretty limited - some online stores just don't deliver here, others expect me to drive to the nearest capital city to pick my fish up from the airport (500km away)! My gut
feeling is that the best option is to buy cories from the most expensive source and just treat them with kid gloves and feed them up once they arrive as they definitely had the best barbels.
<Agreed.>
Is this a good indicator of healthy Corydoras, or is it just that Corys with no barbels are definitely unhealthy?
<Neither really. Worn barbels can happen to otherwise perfect specimens kept in tanks with an abrasive substrate. But since erosion of the barbels does seem to be caused by bacteria, worn barbels can also indicate less that perfect environmental conditions, in much the same way as Finrot. On the other hand, sickly fish can have perfect barbels if the problem is something internal, like worms. So you have to take the barbels for what they are, a sign that some unknown combination of abrasive substrate, lack of hygiene, and ambient bacterial infection has caused barbel erosion, and
whether that's something you can fix will depend on the rest of the fish's health.>
I know it's a bit of marketing trickery to overprice something so that people think its higher quality but maybe for these Corys it's actually true.
<It can be, but if they're all getting them from the same Southeast Asian exporter, it probably doesn't matter a lot. Depends on the retailers. Some will have a good reputation for quarantining their livestock and keeping their aquaria spotless. Some won't. Conversing online at fish forums specific to your country is a good start if you need some feedback from other aquarists. Alternatively, catfish-specific sites, like PlanetCatfish, have forums where you can place appeals for recommended retailers in your country.>
What do you think my best options are? What are the best foods for nursing stressed Corys back to health?
<Same as feeding Corydoras generally, but I'd skip anything live (like bloodworms or Tubifex) in favour of frozen, gamma-irradiated equivalents just to be safe. Otherwise the usual sinking algae wafers and so on.>
How many panda Corydoras could fit in a 5 gallon quarantine tank (that's the best I can do)?
<Definitely limited, but 2-3 shouldn't have problems for a few weeks.
They'll be skittish in such small groups though, so keep the tank shady and put it somewhere really quiet.>
I'm prepared to do frequent water changes due to the small size of the tank. I do think in my previous attempts to quarantine Corydoras, I neglected to make sure they were eating really well and did not fatten them up before putting them in with the pushy guppies and that is something I definitely want to do differently in future.
Thanks again!
Cheers,
Bronwen
<Most welcome. Neale.>
Re: Panda Cory Advice      6/17/16
Hi again Crew! After my last email I realised I have a big plastic tub (around 90lt) which is much better for long term quarantine than the 5 gal tank I'd been thinking about using. I already had four double sponge filters running in other tanks ready for a different project, so I stuck them in the tub, along one side. They stick on the side by suction cup so provide a bit of cover underneath. I've set the quarantine tub up for comfort over bare sterility, so there are some Catappa leaves to hide under and a very thin layer of fine sand to snuffle through, the aim being stress reduction and recuperation.
<Understood...>
Decided to get my Corydoras from the closer seller to minimise shipping time. I was expecting heavy losses of panda Cory based on previous experience, so I ordered 7. A friend urged me to try some trilineatus too, dismissing pandas as too fragile, so I got 7 of those as well. I was expecting to lose over half the pandas and maybe 2 or 3 of the trilineatus.
The fish arrived last Tuesday and there was a remarkable difference between how well the trilineatus took to being shipped and how ill the panda Corys were; one had died in the bag too which probably didn't help. The trilineatus looked a little pink/flushed but were very lively and I could only describe the pandas as limp! Worrying; but they recovered quite
quickly upon arrival in quarantine. They all had nice looking barbels! No visible Finrot or white patches, unlike previous batches from this supplier.
<Good.>
It's been over a week in quarantine now and although one or two of them still look a little on the thin side, they are all very lively and I have had no losses! The trilineatus are a little more shy than the panda Corydoras and the two kinds seem to school together a lot of the time as they are pretty much the same size. I didn't think through one aspect of my
quarantine tub, and that was to raise it off the floor to make siphoning out uneaten food a little easier, I have had to resort to using a pipette to manually suck out the pieces that I could see. I put a small powerhead/filter in today to increase water movement and try to help keep the bottom a bit cleaner, and I got an instant reaction from the Corys, almost all of them went into formation and lined up to swim against the current. They seemed to really like it! It is an absolute joy to see a larger group of these little fish swimming together.
<I would agree, and am sure the catfish feel the same way.>
I haven't wormed them yet, I wanted to observe for a while first and I'm still not sure whether I'm seeing a couple of unwell skinny fish, or immature males that are naturally slimmer. It is good being able to look down from above to see how fat they are! The ones that concern me are almost tadpole shaped, instead of the tail tapering in a wedge shape, it is
thin for much of it's length. Maybe it will just take time for them to bulk up and recover? I have been feeding (not all at the same time!)
semi-crushed algae pellets(popular), sinking "tropical crisp" wafers (popular but perhaps too big to handle), shrimp pellets for catfish (ignored, which is odd because these are my sister's peppered Cory's favourite), frozen bloodworm (popular), Microworms (popular and generated some vigorous snuffling), frozen community food (popular but again some pieces were too big to handle and this made the big mess that I have had trouble cleaning up), flake (this just ended up stuck on the sponge filters, not sure if palatable to Corys). Water changes every couple of days, along with rinsing collected food particles off of the sponges to avoid fouled up water. So far so good!
<Yes; while I would not be thrilled to receive underweight Corydoras, it isn't uncommon. If, after two or three weeks, they're still underweight, that's more alarming. For now, I'd go by activity level and things like barbels and fins to see there's no sign of lethargy or physical damage. If the fish are feeding, just give it time, "a little but often" being the
optimal way to re-condition underweight fish, even four to six small meals a day not being out of line. Fish cannot store food inside themselves for long, and if you feed a lot, they poop out most of that food without extracting much nutrition. They're naturally grazers who would be consuming and digesting tiny amounts across the day/night.>
Worth worrying about worming yet do you think? I'm still cautious about Camallanus after the last outbreak, it's possibly the same supplier that send infested fish, and I have plenty of Levamisole/Prazi left, but not sure what the correct dosage for Corydoras would be. I've got doses of 20mg (17mg base equivalent) Levamisol HCL and 4mg Praziquantel per tablet. I've used 1 tablet per 10 litres dissolved directly into the tank water in the past, for guppies/tetras which was very successful for Camallanus treatment. I don't want to wait too long, if they're there, I've seen what damage they can do! And I think it would be hard to spot trailing worms on a bottom dwelling fish like a Corydoras anyway. I also don't want to
overmedicate and damage these Corydoras since they're doing so well so far.
Thoughts?
<Worming shouldn't cause undue harm, if used as directed by the manufacturer. I don't have any unique insight here, and would go along with what's stated on the packaging and in your own experience. I would not hesitate just because the fish are thin or newly imported.>
Many thanks for your continuing assistance!
Bronwen
Australia
<Welcome. Neale.>

 

Problem with Corydoras (Bob??)         4/5/16 Hello crew, as always, thanks for the help and all the good work. <Thanks for the kind words.> Im writing to you today because one of my Corydoras was gasping while on her side... It seemed to recover a few hours later but has now come back it. Tank is 3.5 months old, 150 gallon tank with ph 7.7, and 0, 0, 20 ppm in nitrogenous compounds. <All sounds fine.> I have had this Corydoras with me for about 2.5 years its my oldest Cory. there are 3 other in the tank ( same species). I cant avoid looking at her belly and think she's probably underfed. <Would seem so; do feed, generously, at night if you have lots of nocturnal fish, and you do. Assuming a 5-6 Corydoras, 5-6 Kuhlis, and the Whiptail, I'd be adding one or two algae wafers 3-4 nights per week. Check in the morning if any food is leftover and adjust accordingly.> I feed twice a day, in the morning for most of the fish and an hour after turning off lights for the Kuhlis, Corydoras, Otos and Rineloricaria parva. I also noticed today she seems like she broke her lateral fin spine? I have attached some pictures... She still swims but she's disoriented and hand feeding is not working.. :( <I am not optimistic here. I do wonder if she has a Mycobacteria infection or similar, which can cause wasting, disorientation, and skeletal deformities. I'm cc'ing Bob Fenner to see if he can add anything more specific. You might also try asking at PlanetCatfish, an excellent website and forum specific to catfish, and there may well be people there who have seen this precise thing in Corydoras and know how to treat it.> Thank you, for your time Roberto <Welcome. Neale.> Problem with Corydoras    /RMF          4/5/16 <8.7 megs of pix; why? > Hello crew, as always, thanks for the help and all the good work. <Welcome> Im writing to you today because one of my Corydoras was gasping while on her side... It seemed to recover a few hours later but has now come back it. Tank is 3.5 months old, 150 gallon tank with ph 7.7, and 0, 0, 20 ppm in nitrogenous compounds. <pH is a bit high, but what stands out the most is that this fish's barbels are gone; worn away... Indicative of being placed on an improper substrate usually> I have had this Corydoras with me for about 2.5 years its my oldest Cory. there are 3 other in the tank ( same species). I cant avoid looking at her belly and think she's probably underfed. I feed twice a day, in the morning for most of the fish and an hour after turning off lights for the Kuhlis, Corydoras, Otos and Rineloricaria parva. <Okay; what are you feeding? Are you sure (apparently not) that this fish is getting sufficient nutrition?> I also noticed today she seems like she broke her lateral fin spine? <Pectoral> I have attached some pictures... She still swims but she's disoriented and hand feeding is not working.. :( Thank you, for your time Roberto <The usual; sending you to read. Start here: http://www.wetwebmedia.com/fwsubwebindex/CoryDisF3.htm and all the linked files above. Bob Fenner>

Re: Problem with Corydoras        4/6/16 Thank you, about the barbels, i got him like that from the beginning, <Ahh> i have very fine volcanic gravel ( smooth) grain size is just a bit bigger than silica sand... Kuhlis and the other Corys have healthy barbels, as far as i can tell. <Good> I am feeding a mix of tetra min tropical tablets and Spirulina tablets for bottom feeders... Eventually i drop some granules or grindal worms which go directly to the bottom... I really don't make sure everyone eats... I commonly just look at where i placed the food and i would see Kuhlis and Corys going about and assume everyone's fed. <I wouldn't just assume. Do observe your livestock to assure they're getting enough to eat> That black patch where the broken fin is a bacterial infection right? <Likely so; yes> I just cleaned the substrate. ( high tech planted tank i don't vacuum much but i realized the bottom was quite dirty) and made a 20% water change ( just did a 50% 4 days ago) i have moved the Cory to a 3 gal hospital, with tank water and a cycled sponge( have several lying in my tanks) still reading, deciding if go about using antibiotics. Thanks Roberto <Thank you for sharing. Bob Fenner> Re: Problem with Corydoras        4/6/16 Thank you, about the barbels, i got him like that from the beginning, i have very fine volcanic gravel ( smooth) grain size is just a bit bigger than silica sand... Kuhlis and the other Corys have healthy barbels, as far as i can tell. <This is worrying. Not convinced volcanic gravel is smooth enough. Most of the traded stuff doesn't come from volcanoes, it comes from the glass making industry, and it's pretty sharp at the sort of scale we're worried about.> I am feeding a mix of tetra min tropical tablets and Spirulina tablets for bottom feeders... Eventually i drop some granules or grindal worms which go directly to the bottom... I really don't make sure everyone eats... I commonly just look at where i placed the food and i would see Kuhlis and Corys going about and assume everyone's fed. <Which is often fine and probably is if every catfish and loach is nice and healthy. But do review in this instance.> That black patch where the broken fin is a bacterial infection right? I just cleaned the substrate. ( high tech planted tank i don't vacuum much but i realized the bottom was quite dirty) and made a 20% water change ( just did a 50% 4 days ago) i have moved the Cory to a 3 gal hospital, with tank water and a cycled sponge ( have several lying in my tanks) still reading, deciding if go about using antibiotics. Thanks, Roberto <I'm not wildly optimistic, but a robust course of antibiotics does look like the best possible chance of helping this Corydoras. Cheers, Neale.>

Sick Albino Corydoras       3/20/16 Hi crew, Firstly, thank you for the reply to my previous email about my snails. Today I am writing about one of my albino Corydoras. She has been so happy and healthy until yesterday. As a matter of fact she has been laying bunches of eggs in the recent weeks. Three of her fry are a few weeks old and going strong(I'm a first timer)! Before I go into her symptoms I just want to mention a change I made recently that raised ammonia for the first time in nearly a year. A week ago, I transferred about a dozen juvenile and 2 senior apple snails into her tank(29 gallon planted, sanded tank with 9 Corydoras, 4 zebra danios, 6 white/black skirt tetras, moderate number of trumpets and a few Nerites). I noticed red spots on her yesterday and today there were more. After testing the water the only thing out of the norm was ammonia which was 0.25 ppm. Aside from the red spots she is lethargic, generally inactive and appears to have swollen eyes (one more so than the other. I'm concerned that this is more serious than ammonia poisoning because she is the only fish showing any symptoms. I have isolated her to a floating container in the tank for now and attached some pictures. Thank you for taking the time out to read my message. Danielle <Hi Danielle. Your little Corydoras has a type of opportunistic bacterial infection that is sometimes called "Red Blotch Disease" by catfish keepers because of its appearance. The non-zero ammonia is almost certainly part of the story, but I'd also be checking if the substrate needs a good clean and making sure there's a good current of water passing over the substrate. Basically, it's a result of stress. Tetracycline is the usual medicine for Red Blotch Disease, but improving living conditions is absolutely crucial as well. Don't forget to remove carbon (if used) while medicating. The swelling can be reduced by adding Epsom Salt at a dose of 1 tablespoon Epsom salt per 5 US gallons/20 litres. Hope this helps, Neale.>

re: Sick Albino Corydoras       3/21/16 Thank you very much for your help Neal. <Welcome.> I had read through the site about this issue and re-read the threads and articles after receiving your response, so I would like to share the results with you. As mentioned in one of the articles on your site (http://www.wetwebmedia.com/ca/volume_6/volume_6_2/mycobactera.htm ) , I did see results simply based on changing the main cause which in this case was water quality. After running errands most of the day(including picking up the tetracycline), I returned and noticed a major improvement in my Cory. <Good; these are normally resilient fish.> The only thing I did was isolate her to a floating tub (daily water changes) and added the Epsom salt as you suggested. I've attached pictures of her which were taken immediately after adding the first dose of tetracycline. I chose to go ahead with the antibiotic just in case the changes I've made aren't enough for her to make a full recovery. <100% the right thing to do.> However, it's clear that the improved water quality and especially the addition of Epsom salt are responsible for her progress. <Could well be.> The swelling has gone down so much that I wouldn't even be able to recognize her if she wasn't separated from the others. Can't thank you enough for your help and patience. Danielle <Nice to hear a happy ending! Cheers, Neale.>

Please help my panda Cory!      11/14/15
Mature tank, 30 gallons, 5 panda Corys, 3 zebra Otos, an African dwarf frog, 7 mosquito Rasboras, some amano shrimp, Eco Complete gravel substrate,
<Ah, this might be the problem!>
planted tank, Aqueon 30 filter, TopFin 10 filter, 20% water changes weekly, 7.0 pH, Ammonia 0 ppm, Nitrite 0 ppm, Nitrate 2.0 ppm
In the past 2 days, one of my panda Corys' barbels have almost completely eroded and today he has developed a white fuzzy cotton-looking patch on his head. He is lethargic, not eating, and stays away from the other Corys.
I'm worried that this could be columnaris because I have noticed tiny white things on the glass that sway with the current. Or do you think it might be a bacterial infection that has also developed a fungal infection? The other 4 panda Corys are acting completely normally and look healthy. What should I do?! I would hate to lose this little guy!
<How abrasive does the gravel feel to you? Here's the thing. Barbels erode because of a combination of physical damage (caused by sharp substrates) and subsequent bacterial infection (very similar to Finrot). Unfortunately for the Amano 'Nature Aquarium' brigade, substrates that plants like are replicated using quite abrasive materials, often byproducts from the
glassmaking industry. While not a problem for tetras, Otocinclus and shrimps, anything that roots about in the substrate, like Corydoras, is going to be less happy. Corydoras not only sift the substrate with their barbels, they like to stick their heads right in and swallow the substrate, spewing it out of their gills. It's adorable when they do it on a sandy substrate, but isn't going to work on traditional gravel or sharp sand. So, in situations where Corydoras are being kept, you're almost always better off keeping them on smooth lime-free sand (smooth silica sand or pool filter sand work well, and cheaply) or else the finest, smoothest pea gravel you can find. There's nothing to stop you using a plant friendly substrate underneath a gravel tidy (basically a plastic mesh) and then add 1 cm or so of the catfish-friendly substrate on top. Plants couldn't care less. Might need to make a few holes in the gravel tidy for plants with deep roots, but most plants will happily send their roots through the mesh in time. Anyway, this would be my first line of thought: is the substrate at fault. Try quarantining the suspect catfish in a tank with no substrate (8-10 gallons is ample for one or a few Corydoras, temporarily at least)
and see if they recover (medicating as per Finrot). Make sense? Neale.>
Re: Please help my panda Cory!
Absolutely. I'll try that first.
<Cool. Neale.>

 

Costia on Bandit Cory(s), invert safe treatments?          5/27/15
Hi, I have a planted 65 gal tank 4 years+ running with honey gouramis, kuhli loaches, Hengle's Rasboras, bandit Cory's, Amano shrimp, Nerite snails, Oto cats. I think the Oto cats brought in disease and I had some loses of livestock and then things seemed to stabilize with no more dying fish. Some of the Cory cats, one in particular, have gray slime on them that seems to be 'Costia'.
<Costia, now called Ichthyobodo, is an awkward parasite for sure. It's one of the causes of Slime Disease, though not the only one, so do be aware of that. Curiously, but significantly, Costia is harmlessly present in most tanks, and only becomes problematic when the fish become stressed. So it's important to try and think of why that might be the case. In any case, there are various proprietary treatments out there, such as eSHa 2000 (no formalin or copper), QuickCure (has formalin in it though) and Interpet Anti Slime and Velvet (this latter also contains formalin). Otherwise, apart from formalin (which does indeed work well against Costia) any metrifonate-based medication should work well.>
I have gradually turned the heat up from 77 F to 83 F. The slime seems less on the worst Cory but still there. I can't net them out of the tank, too many obstacles. The invertebrates make using most of the medications recommended for Costia not safe to use.
<Indeed. Anything with copper or formalin in it may be toxic to shrimps, snails, and potentially sensitive fish including loaches and catfish. So you've got problems.>
Is there anything else that I can/should be doing? Does Paraguard have any effect on Costia?
<Paraguard has a chemical similar to formaldehyde in it, so wouldn't be an obvious choice for use with your community of species.>
Prazi-pro did not help at all.
<Obviously not. It's a dewormer.>
Thanks,
Jeff
<Cheers, Neale.>
Re: Costia on Bandit Cory(s), invert safe treatments?      5/28/15
I'm not sure if I can get eSHa 2000 here in Canada. I'll look around.
<Or order online, via eBay, etc.>
The inverts in this tank have been through Paraguard treatment before without losses. I've never had it obviously cure anything, but if you think it would have a chance at Costia I'm willing to try it. I have a bottle handy. Should I adjust the dose for the Cory cats or Otto's?
<Adjusting doses down is fairly pointless. Generally the dose stated on the bottle is the dose needed to kill the parasite. Half doses might work, but then again, they might not. You could consult with the manufacturer for
guidance. SeaChem do have an FAQ, here:
http://www.seachem.com/support/FAQs/ParaGuard.html
They don't sell this product as "reef safe" as you can see, which means it might be toxic to invertebrates... but then again, it might not! That's probably about as sure a reply as you're going to get on this product.
Cheers, Neale.>
Re: Costia on Bandit Cory(s), invert safe treatments?      5/29/15
I tried the Prazi-pro first because I thought it might be skin flukes. I'll try the Paraguard after I do a water change on the weekend and see if that helps. If I go much higher with the water temps I am going to lose some plants.
I'll let you know if it seems to do anything.
Thanks, Jeff
<You're welcome, Neale.>
Re: Costia on Bandit Cory(s), invert safe treatments?        8/15/15
Hi Neale,
<Jeffrey,>
Is been awhile but I thought that I would let you know that the ParaGuard did not do anything. However, I had some PolyGuard and that cleared up the problem with 2 doses, maybe 3, I can't remember exactly.
<Cool.>
I have another question. I switched my tank to Fluorite black sand substrate about 5-6 months ago because I thought the eco-complete was too sharp on Cory cat and other bottom feeders barbels.
<Ah... not the best idea.>
Frustratingly, Cory cats I have put in there since have still developed eroded barbels.
<Yes. Fluorite sand is, as I understand it, manufactured, not a natural product. It isn't a natural substrate and remains sharp enough to cause problems for bottom dwelling fish. An excellent choice for Amano-style tanks with midwater fish (tetras for example) but not for catfish, loaches and so on.>
I know bacteria is another possible cause of this but the question is how to avoid it.
<The erosion of the catfish barbels is a two-step process. The sand creates scratches in the skin tissue, and bacteria (similar to Finrot) can get in. Whether there's a threshold of dirtiness required for this second step I do not know, but I'd assume not because catfish whiskers are just fine in silica sand tanks with lots of organic detritus, which would seem to have more bacteria than clean fluorite sand.>
I do a 30 percent water change every week and the tank is not heavily stocked. It is a planted tank, so I do not vacuum the bottom during water changes.
<Generally no need.>
There are two AquaClear filters and a circulation pump, so there are no noticeable dead spots with piles of waste building up in them.
Thanks,
Jeff
<It's the sand, Jeff. Swap it out for plain vanilla smooth silica sand from a garden centre or pool filter sand supplier. Will look hideously bright at first, but over time the grains darken (algae and bacteria, I guess) and you'll find it much more agreeable. Alternatively, replace the Corydoras with a midwater catfish species such as Dianema spp., Asian Glass Cats,
African Glass Cats, or even Dwarf Upside Down Cats. Cheers, Neale.>

 

 

Sick Albino Corydoras Hello and thank you for taking the time out to read this. I am writing regarding an albino Corydoras catfish whom I recently rescued from poor living conditions at a local pet store. <A kindness, but sometimes misguided: if a fish dies in an aquarium shop, that's a loss, and the owner will be less likely to buy that species; if the fish is sold, even if it's unhappy, the owner sees a profit, and re-ordering that species is likely. If you see a pet shop not caring for its livestock, then contacting the body that issues animal sales licenses is the best step forward, often a city or state government agency.> To be honest, I am not a preferable candidate to take on such a task. I only recently (2 weeks ago) started my first tank (10 gallon). <A bit small, but certainly viable for a small group of Corydoras, perhaps 3-4 specimens rather than a full school of 6+.> Solely following the advice of a pet store employee, I soon learned that I had made mostly poor choices. I am diligently trying to learn as much as I can, while attempting to cycle my tank using SeaChem stability and prime. My tank inhabits 3 albino Corydoras, 2 Danios, 2 mystery snails and 2 cherry shrimp. <The snails and shrimps were bad choices. But the Corydoras and Danio combination is a good one -- though again, 10 gallons is a bit small for such active and quite big (5 cm/2 inch) fish.> I have various aquatic plants and recently upgraded to an internal power filter for tanks up to 30 gallons (after adding the sick Corydoras to my tank, I thought it would be safest to increase filtration since my tank is not yet cycled). <Some merit in that. Adding some Floating Indian Fern would be a very good idea. These jump start the filtering process and also remove some pollution directly, so are always worthwhile. They also inhibit algae.> Originally I quarantined the sick Cory since I honestly had no idea what could be wrong with him. He was pale, listless and would enter what appeared to be periods of paralysis, which lasted for up to 4 hours. I thought he had died multiple times during his 3 days in confinement. Then suddenly he would dart around his tank and remain active for a short time. He had red streaks/blotches on his body, darted to the surface for air often and would lie on his side motionless. <These red blisters are suggestive of "Corydoras Plague" or "Red Blotch Disease", which is (probably) a bacterial infection seen in stressed and damaged bottom dwelling fish. A combination of improving the substrate (removing sharp sand/gravel), improving water quality, and treating as per Finrot usually helps.> His gills would either appear to be deeply pulsating or not moving at all. During his time alone in his small tank, I was treating the water with prime and stability. I was also changing 50% of the water daily and keeping everything as clean as possible. He did not eat (I tried almost every option possible) and he did not even acknowledge food when it was right in front of him. I forgot to mention that his barbels are very short, barely visible even. <Again, a very good indicator of bacterial infection caused by the wrong environment. In brief: sharp sand or gravel damages the whiskers; poor water quality inhibits the immune response; bacteria infects the wounds; the whiskers erode away.> I only found your site today and this was after I made the bold (and possibly foolish) move of transferring my sick Cory to my 10 gallon tank. I posted endless requests for help on so many forums, but received very vague responses. Through research, my best guess is that the Cory had ammonia poisoning. After day 2 of confinement, his red blotches were gone and he no longer displayed long periods of paralysis. <Good.> Although not nearly as active as my 2 healthy Corydoras, there was a significant improvement. Without any guidance and a true lack of knowledge, I convinced myself that he was depressed, lonely and recovering from ammonia poisoning. I have read that Corydoras should be in groups, so I moved him to the larger tank in hopes that the company would influence him to thrive. <Certainly wise. Red Blotch Disease isn't contagious as such, and is more to do with the catfish being stressed/damaged than "catching" something.> My sick Corydoras has only been in the larger tank for about 15 hours, but he seems to be doing well. He has definitely taken to the other Corys and spends time grazing, swimming and even EATING with them(first time eating since I brought him home). However, he still appears pale and appears lethargic at times. I am very nervous that my irresponsible and uneducated choices will take a turn for the worst. I worry that I made the wrong choice for both the sick Corydoras and the rest of my fish. I am hoping you wouldn't mind offering some insight and advice. My only plan of action is to continue with daily water changes along with treatments of stability and prime. I have been testing parameters using test strips so far, but today I purchased the API testing kit. Once I learn how to use it I can offer better details on water conditions. My test strips have been showing values of 0 for both nitrates and nitrites(I started stability about 4 days ago). Ammonia levels have remained at zero. I don't have the specific value on hand for hardness, but the key showed it to be in the "hard" range. My pH has been at 7.2 I believe. The alkalinity was very low. <Corydoras are very adaptable: provided water chemistry is stable, it doesn't matter much what the precise values are within, say, pH 6-8, 1-20 degrees dKH. Don't overheat Corydoras though: 25 C/77 F is optimal for sick specimens, a degree or two cooler for maintenance. Incidentally, 24 C/75 F would be ideal for Danios, Cherry Shrimps and Apple Snails!> The strips don't offer exact numbers unfortunately, so I apologize. I will get working on the API kit so that I can offer more details if/when needed. Thanks again for taking the time to read this. I apologize if I left anything out. Sincerely, Danielle <See above. Reviewing the environment and using an antibiotic should help. Cheers, Neale.> Re: Sick Albino Corydoras     7/20/15 Hello again, Thank you so much for the prompt reply. I was honestly expecting a bit of criticism in your response, but was very relieved that my choices were not (completely)ignorant to say the least. <Good.> Since my last email, my recovering Cory is doing fantastic (whom, by the way has taken on the name "Casper" not only for his albinism (obvious), but also for the multiple instances that he appeared to have come back from the dead =) ). <So not named after Caspar Weinberger then?> His improvement has been so ideal that I have yet to pursue treatment with an antibiotic. This decision was just that of a mothers intuition I suppose, since I avoid unnecessary drugs/chemicals within my own family. If you feel that proper treatment is still necessary despite his progress, please let know. <If a fish is healing under its own steam, then no, there's no need to use medication. But do be on the look out for relapses and act accordingly.> In the last few weeks I have fallen in love with this enjoyable responsibility/hobby, especially with my 3 sweet little Corydoras. How anyone can resist their innocent nature or the way they blink at you through the glass is beyond my comprehension (*Love*)! <Certainly entertaining fish. The blinking is, of course, an adaptation to living in a muddy environment, where regular blinking helps to wipe away silt from the surface of the eyeball. Fish don't (with a few exceptions) have anything comparable to our eyelids, so they aren't self-cleaning in the same way (indeed, in an aquatic environment it's not normally necessary; eyelids are an evolutionary response to using fish-type eyes in a dry air environment).> I have spent an unreasonable amount of time (while juggling a toddler) reading through the contents of your site. That being said, I purchased a 29 gallon tank today and what I understand to be equivalent necessities for the cycling process. <An excellent size aquarium. Can't go wrong with 20-30 gallon tanks. A nice balance between size, cost and stability.> I would love to do it the right way this time and provide a desirable home for my current fish while adding to my small group of Corydoras. <Provided the filter is an internal or external filter, you simply swap from one tank to the other (switched off while it's out of the water though!). Transferring some/all of the aquarium water is a plus too, as well as substrate, plants, etc. All this will jump start the new tank instantly. Easy!> In response to your comments I am also considering transferring the cherry shrimp to a small species tank, so thank you for that insight. <Agreed: mixing Cherry Shrimps with some other 'nano' species in the 10 gallon would be great. An unheated tank stocked with Cherry Shrimps and subtropical species such as Least Killifish would be highly entertaining. I have just such a tank in the kitchen. Trivial to maintain, cheap to run, and some babies of both species too!> So this is where my questions and/or current understanding comes in to play(please correct anything I may have misinterpreted)! The internal power filter that I am currently using has both sponge and carbon components (I also added ceramic rings). After reading your articles on freshwater filtration and media, I understand it would be best to replace the carbon cartridges with filter wool. <Yes; carbon has only one function, removing unwanted chemicals, and for most aquarist, this is pointless. It'll remove medicines just as well, making it a positive hazard if you have sick fish.> I mentioned in my last email that I am cycling with fish using stability and prime. My values are improving and I seem to be on the right track with my 10 gallon tank. Would you recommend that I use the stability in the fishless cycling of my 29 gallon tank? <See above. Just swap the filter (and the fish) to the 29 gallon tank. If you can, put an equivalent filter in the 10 gallon, and cycle that one using Cherry Shrimps, which generally sail through the process if you don't add any food beyond allowing them to graze algae.> Another concern of mine seems to be an overly covered topic on your site (and I genuinely apologize for adding to it). Since the Corydoras are at the top of my new infatuation, I am going with a sand substrate in the upgraded tank. I was unable to find silica sand sold locally. <In the US, often sold as pool filter sand.> Anxious to start the cycling process (and help Casper regenerate his lost whiskers asap), I purchased an adequate supply of sand by CaribSea called super naturals. I believe it to be appropriate for the cories based on what I've researched, but would appreciate any opinion you may have to offer on this product. <Provided the packaging says "suitable for soft belly fish" or "suitable for sand sifting fish" or something along those lines, you're fine. Carib Sea used to expressly state this on their website, yes or no for each of its brands/products, but it's been updated and this information dropped. In any case, you're after a fine, smooth substrate different from sharp sand.> I am worried that the maintenance of such a fine sand may be a bit beyond my experience level (when adding in the full time care of a feisty toddler and the final semester of a nursing program). <It's easy to maintain. Silt sits on top of sand. It sinks into gravel. So in a gravel tank, the dirt is "out of sight, out of mind" but it doesn't vanish. Cheap tip: buy a turkey baster and use this to spot clean the tank whenever you see piles of gunk you can't ignore. For what it's worth, Corydoras don't mind a bit if mulm -- it's what they mostly consume in the wild.> If you have no personal opinion on this specific product, please feel free to disregard (with much understanding). Finally, I have made a hypothetical observation with my albino Corydoras regarding possible sensitivity to light. It is somewhat hard to describe their behavior when the (led) lights have been shining down on them for a while. If I had to compare the symptoms to those of a human, I would say it appears as if they are experiencing absence seizures (2 of the 3, including Casper). <Seems plausible. Review human albino eyesight, and for fish, it's probably similar, except of course water cuts out UV light almost completely. Corydoras are naturally shade-dwelling fish, and the addition of floating Indian Fern makes them a lot happier that bright overhead light.> They have been unresponsive to firm taps on the glass while lying right beside it. Then a fraction of a minute later, upon tapping they suddenly jolt to the other side of the tank and all over for a few moments. They don't behave this way when the led lighting is off. Is this an issue that you've ever been made aware of regarding albino species and bright lighting? <Yes; it is widely observed by objective fishkeepers that albino fish are less robust than their normal relatives. We've bred them because they look nice (to some people, anyway) but such fish wouldn't last long in the wild.> In addition, my tank is planted with plenty of hiding spots. Even so, when the lights are on the 2 cories choose to remain unsheltered, eventually entering this odd "hypnotic" state. I find it odd that they don't try to hide if it's bothering them. <Corydoras are not very smart. Causes problems if kept with territorial fish -- they simply fail to learn to avoid territories.> In a way, to me this makes their behavior seem even more similar to that of am unsuspecting epileptic. <Not beyond the realms of possibility. Fish behaviour is both more complex than we assumed even 20 years ago but also far less well studied than that of mammals or birds. We're observing all sorts of things we never expected with fish, such as play behaviour (hitherto associated with "higher" vertebrates) as well as what appears to be the ability to feel pain (this latter still contentious, but if it's true, profound in terms of how we catch fish to eat and keep fish as pets).> I have added 3 pictures of Casper - the first 2 while quarantined and at his worst. The 3rd at his best state so far, taking a rest after playing with the other (not the best quality, but notable to his improved color and "plumpness"). Just proud of him and thought I'd share :) ! <Looking better than last time!> Thanks so much again for your time and all the very valuable information on your amazing site. It has been quite the life saver for my fish (as well as my own sanity!).Danielle <Most welcome. Neale.>