FAQs on Oscar
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Tiger Oscar attack (Bob, Oscar damage or Catfish
I have had 2 Tiger Oscars in a 125 gallon tank for over a year
with a 14 inch Pleco .
They have always gotten along well, as well as can be
<Indeed! Oscars are not famously sociable except as mated
The Oscars are easily 15 inches and 12 inches. I clean their tank
every 3rd week, draining close to 75% of the water each time. I
also use this time to "rearrange" the decor in the
tank, to keep them entertained.
<Likely helps to break up territories a bit, which is good,
because it prevents any one specimen become super-dominant.
That's the theory, anyway.>
They are fed flake/frozen food daily, and they get about 25
feeders every Tuesday to chase around.
<No, don't feed them feeder fish! It's VERY VERY VERY
bad for them. Gosh, I have no idea why shops still sell these
"parasite bombs". Let's put the cruelty aspect
aside (and it is cruel). In terms of nutrition, Goldfish and
Minnows suck. They contain a lot of fat and something called
Thiaminase that breaks down Vitamin B1. There is AMPLE laboratory
and real world evidence that Thiaminase causes predatory animals
including fish all kinds of health problems, from reproductive
issues through to poor immune responses and deterioration of the
nervous system. The use of feeder fish also increases aggression
for reasons not altogether understood. There are absolutely NO
good reasons to use feeder fish, and lots of reasons not to.
Thankfully you can't buy them here in England so it's
mostly a non-issue, but the US pet trade still sells them,
creating all sorts of problems for American aquarists. Want to
give your Oscar something it would eat in the wild? See those
massive jaws, they're for crushing things! So try snails or
crayfish or whole shrimp. They love earthworms!>
It keeps them from fighting with each other.
<No it doesn't. For some reason it actually makes them
Last week, I did not stop to buy them feeders. They were fighting
by Thursday, and by Saturday morning the smaller Oscar was laying
on the bottom of the tank, covered in white "fuzz"
spots, and there is a side of their tank without gravel where you
could see the scales on the bottom.
<I don't think this had anything to do with you not buying
Indeed, it's more likely that buy using feeder fish
you've increased their tendency towards aggression, and this
week it might have spilled over into outright violence. That
said, by the look of the damage, I think the Pleco is to blame
here. Oscars fight by wrestling, and usually you find damage to
the jaws, face and fins as they bite at each other. This looks
like someone scraped away at the flanks. It's possible one
Oscar damaged the other, and the scent of blood was enough to get
your Pleco hungry. Within the confines of your aquarium the
stressed or otherwise weakened Oscar was an easy target.>
My wife thought she was dead. When I got home from work, I
grabbed a net and was going to remove her from the tank, but as
soon as the net hit the water she moved. I moved some plants and
decor in the tank so she has her own little "cove"
where she can be sheltered from the other Oscar completely and
not have to worry about defending herself. She still shows an
appetite at feeding time, and will swim around on occasion,
usually after lights are out. What is the best medication to use,
anti-fungal as a preventative, stress coat, or Melafix?
<Obviously needs excellent water quality and its own tank.
I'd treat with an antibiotic given the scale of the damage;
blood poisoning or Finrot-type infections are very probable
otherwise. Melafix is largely useless, and this damage goes
beyond what Stress Coat can do alone, though using it alongside
antibiotics would be a good idea.>
And how long will it take for the scales to regrow?
<This will take months to heal.>
Any other advice would be greatly appreciated.
<Please do stop with the feeders. Ethics aside, they're
just D-U-M-B dumb.
If you must use live fish for some obligate piscivore -- which
your Oscar isn't -- you have to breed your own livebearers or
killifish at home, as these lack Thiaminase and have less fat.
Cyprinids such as minnows and Goldfish aren't an
Thank you, Eric
<Glad to help. Cheers, Neale.>
This Has Stumped the Oscar Community 8/28/10
Oscar With Skin Slime on Head
Dear WWM, I might be able to have an ailment named after my
Oscar. No one has seen it. Attached are pictures of mystery pots
that come & go. He had them once in January, March, and
April, and at least twice in June. The first day you can only see
them up close at a certain angle. In 1-2 days you can see them
from across the room. He flashes but not too much. In a day or
two they're gone (until recently). They don't go beyond
the dorsal fin and they aren't always round.
He's a year old and shares a 90 gallon tank with a Firemouth
and 3 Silver Dollars (they are fine). The tank is filtered by two
Eheim 2215s. I do 70% water change every 5-7 days. Ammonia &
nitrites are always 0. Nitrate is orange before water changes.
(API tests). PH in tank and tap is 7.4, KH is 6, GH is 8, temp
79-80. I use Prime, no salt.
This tank has been up since May. His first tank burst. I was
hoping the mystery spots would stay there.
He eats Omega One pellets, Massivores, freeze-dried krill, Omega
One Veggie Rounds. About 1/4 of his meals are soaked in Vita
Chem. I'm trying to get him on an every other day schedule
but he begs like a puppy.
I've tried removing everything from the tank except two
I've tried correlating the emergence of these ghostly spots
with how long it's been since a water change, but there's
no obvious connection. They're getting worse. For the last
two months he's had them most of the time.
I've tried Seachem Paraguard, the Melafix-Pimafix combo, and
I'm having trouble finding anyone who's even seen
Have you seen anything like this? What would you do? Any help is
greatly appreciated. Thank you for your time and dedication to
Best, John (More pics available upon request. It's
unbelievable how fast this used to vanish.)
< I would call it a bacterial infection that starts on some of
the pores around the head and spreads out when conditions
deteriorate. I would recommend a treatment with Nitrofurazone and
keep the nitrates under 20 ppm with water changes.-Chuck>
Oscar with one eye
Hello! We just set up a 55 gallon aquarium and I mistakenly purchased a
black and orange Oscar with one eye. It appears that he was born with
one eye because I see no battle wounds. We also purchased a Jack
Dempsey and Texas Cichlid about the same size as the Oscar. I was
wondering if you thought that the Oscar might be less aggressive since
he has only the one eye? If so I would like to get one or two more fish
(possibly a Red Devil and a Pleco). I know that they will grow and fill
the tank more, however we are going to be setting up a larger tank
within the year that we can transfer them into. Just curious to hear
your opinion because I don't want to overfill the tank, but I also
would enjoy a couple more fish swimming around! Thanks, Carrie
< The eye problem probably won't make a difference. I would
recommend getting all the fish now and letting them grow up together.
This will allow them to set up a pecking order before they get too big
and can really inflict damage on one another.-Chuck>
Weird Bulge. -
I have a red and black Oscar, I've had it for
about 2, 2 1/2 months. Today I was cleaning the tank, when I got him in
the net, I noticed there's a pink like. Innard or something hanging
from the bottom of his belly, like underneath.
I asked around a little, and got enough different answers, "its
pregnant", "it got bit", "its organs are hanging
Can you please tell me what's really going on?
-Thank you, Cort.
<Hello Cortney. Almost certainly this fish has a prolapse of the
Quite common when Oscars are kept in chronically poor conditions.
Apart from fixing the environment, add Epsom salt (not regular salt) at
1-3 teaspoons per 5 gallons, preferably with a combination of
Metronidazole and Nitrofuranace as well in case there's an
associated infection. Review also the basic needs of Oscars. Many folks
start off bad by keeping them in small tanks and feeding them live
fish; both of these things will quickly make a healthy fish sick. 55
gallons is the minimum for a singleton, and water quality must be
excellent. No nitrite or ammonia, and nitrate below 20 mg/l. Weekly
water changes essential. Filter should have a turnover rate not less
than 8 times the volume of the tank per hour. Use either dried foods or
live foods such as earthworms or snails. Don't use feeder fish
unless you want to kill your fish. Water chemistry not crucial, but
shouldn't be too hard.
Do need more information for a more precise diagnosis. Cheers,
What is up with my Oscar
Oscar With Large Growth on Head 8/19/10
I have been referred to your site from the Houston Fish Box I am
attaching two pictures of my female Oscar. About a month ago she
started getting this knot on her head. Now is gross and huge and
looks like some kind of ulcerated tumor! I have tried water
changes, increasing aquarium salt, fungus tablet
treatments. Nothing is phasing this growth. Any suggestions what
< I think it is an internal infection. I would check the water
Ammonia and nitrites should be zero and the nitrates should be
under 20 ppm. I would treat in a hospital tank with a combination
of Metronidazole and Nitrofuranace. This combination treats a
large range of
Urgent Oscar help! Am trying to
find answers but really need some advise... please please please
Firstly, I must say that I have been reading some of the wonderful
advice on this forum and site... most helpful!!
I need to ask for a little bit of help right now, and I do apologise if
I am asking something that has already been answered. I am searching
through the answers to questions and articles on this site, and approx.
and am coming up a little lost in finding what I need.
My partner has built me a new tank, dimensions 150 X 60 X 75 cm. (630
litre capacity) which I am currently in the process of setting up and
cycling. I also have a 2ft tank with a 55 litre capacity, which has
previously been used for breeding guppies and Bettas.
<What volume or what size system is the Oscar in presently?>
Filtration is an AquaOne 101F Power Liquid Filter 400l/hr with the
attachment to have the spray sit slightly above the water for agitation
and oxygen, as well as one airstone for added oxygen. The tank
parameters are as follows:
<Low, too low for Astronotus>
GH: 10 dH (approx. 175 ppm)
<Ammonia? Needs to be 0.0 ppm>
0 -- 0.25 ppm. (have treated for white spot with Methylene blue, tinges
the test result ever so slightly and makes it hard to determine... I
believe this would be closer to 0 due to water changes as explained in
Unfortunately, I have run out of reagents for both my Nitrite and
Nitrate test kits, and am heading down to get the water tested at my
LFS as well as purchase new ones, just wanted to shoot this off
quickly!! I do however maintain my water changes religiously, monitor
food waste and adjust feeding accordingly to minimise any waste and
contamination in the water, I also observe my fish closely and so far
have been travelling wonderfully, last recorded levels were nitrites 0
ppm and nitrates 0.25 ppm.
Occupants consisted of 3 x adult guppies, tank had been running for
approx 12 months.
Nothing had changed in the aquarium other than the addition of an
airstone and new plant. The plant I am uncertain about and has since
been removed -- it was artificial, and made out of more like a
silk/fabric. I purchased it from my LFS and claimed to be
'approved' on all packaging etc. However, I'd rather be
safe and have taken this out just incase it was possibly breaking down
or throwing off some kind of toxin.
The Oscars were added to this tank
<...55 litres? Too small for any but the smallest of Oscar
for the time being until their home has been sufficiently cycled which
should only be another 4 weeks at the most. I figured if they eat the
guppies then so be it, they are intended as breeders for feeder fish
I have recently (one week) purchased two juvenile Oscars. One tiger and
one red. Both were approx. One inch at the time of purchase, were
strong, healthy and paired up at the shop. I bought one to begin with,
but 'she' (as I've dubbed her, when she's larger
I'm almost certain it will actually be male judging by behaviour,
but right now I'm calling her a girl) was rather sulky and
<Very typical behavior for this species when moved>
so the following morning I went back and purchased her buddy, who was
behaving the same way in the shop. However, when I got him home,
approx. 5 hours after release his breathing became a little laboured
and he was quite lethargic, hanging around under the heater. The Tiger
O had claimed herself a cave and would head over to him and it appeared
to 'snuggle'. Laying close, nudging him up and forward, quite
friendly appearing, no tail shaking, fins not extended, no nips. He
seemed to perk up after another hour or so and they were happily
swimming around and cozying up under a rock. I put his earlier
behaviour down to stress and settling in, gave them some blood worms
and both were eating.
The next morning, I found one guppy dead and a little battered,
figuring the Os had just ganged up on them and killed one. Nothing out
of the ordinary for them. The Red O was again under the heater/filter
and breathing heavily and more rapidly than the night before. I checked
the water parameters and came up with the same result. The remaining 2
guppies and the other Oscar were behaving normally. A few hours later,
he was displaying signs of weakness, still laboured breathing, and
leaning to one side or the other, but was able to still swim around.
The tiger O began to ignore him at this stage. I checked the water
again, all fine. I decided to do a 25% change even though it wasn't
due incase I was experiencing a nitrite/nitrate spike -- no ammonia
though. It seemed to have no effect on him. I also noticed a little bit
of white spot appearing on his fins and on one of the guppies, and
treated with 10ml Methylene blue in 55 litres of water (dosage is 0.25
ml which works out as 12.5 ml -- I always slightly underdose with this
just to be safer). Raised the temperature to 29C and the next morning
the visible signs were gone from both fish. Treated again with a
slighter lesser dose (approx 8 ml) 3 days later. However, prior to
redosing, I found that the pH had swung dramatically toward alkaline,
approx 8.3 I have never experienced a swing as dramatic as this or in
this direction. I corrected and it has remained stable again at around
<... I wouldn't correct this, but figure out why the difference,
slowly/incrementally change the water to having the pH
The Oscar continued downhill with his breathing becoming extremely
laboured and fast. He stopped eating and became rather agitated.
Constantly cranky and displaying aggressive signs, tail shaking and
charging anything/anyone (human or fish) who would happen near his
corner. At this point my Tiger O became aggressive and would attack and
pick on him. He ended up with some wounds an I separated the two within
the tank to give him a chance of recovery. I completed another 50%
water change at this point. Approx 3 days after this began and he
stopped eating, he weakened to the point he became caught up in the
current and had trouble staying upright. He would spin around and when
he eventually died late last night, his mouth was gaping wide open. I
also found the guppy displaying white spot symptoms to do the same
thing, and died a little while before the Oscar. Mouth open. I had read
some things about whirling disease before, but thought that it
primarily affected cold water fishes especially salmonoids... I have
been unsuccessful finding information pertaining to it in Oscars and
how to treat. Is this even a possibility???????
This morning, I have found my tiger O beginning to breathe slightly
heavier than normal. I have immediately upon finding this completed
ANOTHER 30% water change, and she appears to have eased a little. She
is still highly active and eating -- however not quite as piggy as
normal. I have only had her for a week, but she is already taking food
from my hand and coming to greet me when I approach the tank. This
morning she was giving me a look as if to say 'I'm not well..
help me! Make it better' I felt so horrible. The remaining guppy is
breathing quite fast but like the O is very active and eating also. I
know it sounds like something terrible is going on in my water -- but I
just can't work it out!!!!! Everything appears fine. I am double
checking with my LFS once I have posted this, and will update shortly
what results they turn up. Perhaps my tests are faulty? ?
Finally, she appeared ever so slightly bloated upon turning the lights
on this morning, and then about an hour later after I had completed the
water change when I checked her, she had done a HUGE poop and looks
ever so slightly emaciated now.
<Might have internal parasitic issue>
This is making me think of internal parasites now, and I have had a
look but so many different things seem possible, I think I really need
a little bit of more experienced and expert advice to help me sift
through the masses of information. Please help me work out what is
going on and how to treat this. I am planning to continue daily (up to
twice daily if necessary) water changes until I can figure out how to
treat this. My thoughts are that if there is a toxin in there, perhaps
from the plant I've removed (??) this will lower the concentration,
and the same for if I'm experience Na3 & 4 spikes...
I really don't want to lose my girl, I've grown so attached
Thank you so much in advance for your time in replying!
<Umm... do re-read what you've sent here... This system appears
to not be completely cycled... I do suspect metabolite "build
up"/poisoning as a/the primary cause of trouble... See WWM re
cycling. Bob Fenner>
Sick Oscar.. Help please
Oscar Lies On The Bottom Of The Tank 7/10/10
Hi Guys, I have a 2 yrs old Albino Oscar about 10" in length. Of
late he has been lying at the bottom of the tank in an upright
position, no labored breathing, no visible signs of parasite or any Ich
on the fish. During feeding he does come up and shows enthusiasm but as
son as he has his food he goes right back to the bottom of the tank and
remains there. Have done water changes have also put in the required
aquarium salt in the tank. The only change observed is that,
irrespective of the water changes I do find a white slime in the water
very often. Kindly advise what could be the issue and the remedy.
Thanks & Regards, Manish K
<Check the water temp. Should be in the mid 70's. Could have an
internal infection that has affected the swim bladder. Isolate the fish
in a hospital tank and treat with a combination of Metronidazole and
Nitrofuranace. You may have to look for the ingredients on the packages
to find out what is in the remedies sold at the stores.-Chuck>
Re: Sick Oscar.. Help please
Oscar With HITH -- 7/12/10
Thanks for your advice, would like to update you about the recent
Just 2 days ago I have observed 2 small holes on the side of my Oscars
I understand it is the Hole in the head Disease and as per the same
have got AZoo Anti Endoparasite from my fish dealer for treatment.
Anything else that you would recommend cause my Oscar only prefers live
fish and raw chicken best part being that he still shows interest in
Thanks & Regards, Manish K
<Try getting your Oscar on a regular diet of high quality pelleted
Live fish carry parasites and raw chicken carries salmonella, which is
not good for you either.-Chuck>
Swollen Oscar 7/10/10
Hi, My name is Stephanie. I have an older Oscar, maybe 8 years old. For
the past 3-4 months, I have been battling Swollen Bladder Disease. He
was not getting better. I basically gave up on medicine treatments and
just kept doing water changes. He would not eat and stayed at the top
of the tank as he was unable to swim down. Sometimes he was laying
sideways on the top of the water. Several times when he had been on his
side for days, I would decide that today was the day to put him out of
his misery. As soon as I would say this, he would make himself
and I couldn't do it. If he was willing to try, so was I. (Yes, I
was a bad fish owner and let the tank get very dirty. I have since
changed my ways.)
Then, out of the blue on Sunday, he acted hungry. I gave him a pellet
and he ate it. Next day, gave him 2 pellets and he ate those. Next day,
I wake up and look in the tank and his bloating has gone way down and
he is swimming normally. And he's hungry! I was shocked. This was a
2 days later and he is having problems. I did a 25% water change as it
was time and I had noticed that he was swimming funny. He is upright
but his nose is close to the gravel and he will do a somersault. Almost
like he is floating in water. I know fish "float" but this is
different and I don't know a better way to describe. He kind of
just floats aimlessly bumping into things.
I also noticed that he is flaring his gills and he turns almost
white/grey in color. I also noticed that his gills are very red and
that the base of his side-fins are red and irritated looking. He also
has some fraying on his fins.
He is in a 55 gallon tank that is cleaned regularly. I tested today and
the pH is 7, NO-2 is <.03and the NO-3 is 12.5 mg. My ammonia test
kit was empty so I don't have that number. Sorry.
I don't know if this is the next "stage" of swollen
bladder disease or what. Just hate to give up on him now after we have
been through so much.
Any help would be greatly appreciated.
Thank you! Stephanie
< Check the water temp to be around 75 F. Treat with a combination
of Metronidazole and Nitrofuranace in a hospital tank.-Chuck>
Re: Oscar Issue
Swollen Oscar II -- 7/12/10
Thanks! That is exactly what I did. He is actually doing much better
this morning and is still eating! Stephanie
< Glad to hear you fish is doing better.-Chuck>
Oscar with HUGE eye --
Oscar With Popeye
Hello, Can you tell me what is wrong with my Oscar? It has a huge
eye and swelling underneath the eye as well. Went to the LFS. One
said search the web and the other has me currently treating the
tank with Maracyn. Today is the 3rd day of treatment and it's
looking bigger. All the water chemistry is fine. I don't know
what else to do. Charlie
<There is an internal infection behind the eye ball. As the
parasites multiply they displace the eye out of its socket. Place
in a hospital tank with clean water and treat with a combination
of Metronidazole and Nitrofuranace. The eye may be damaged beyond
Oscar with HITH and little worms?
Help please :( 6/22/10
<Hi Katie! Melinda here tonight.>
I'm writing because I have a 6 month old Oscar who has
developed HITH. I am treating the tanks with API General Cure
which has Metronidazole 250MG and Praziquantel 75MG and
simultaneously treating with Jungle Anti-Parasitic food pellets
(it says it is safe to treat with pellets during external water
treatments as well).
<Yes, but what of water conditions, which typically lead to
HITH? Ammonia, Nitrite, Nitrate?.>
My fish has exhibited no lethargy or appetite lost in
the least bit so he is gobbling up the pellets.
<Oscars are pretty tough critters. Honestly, they rarely
exhibit signs of illness until very, very late.>
Prior to treating I did a 50% water change, used tap water
conditioner to remove the chlorine and metals and also removed
the carbon filter from my BioWheel.
<Do you test? You should be. Anyone who keeps Oscars should
be. They're just so messy (I mean this with no disrespect to
these lovely fish)!>
Tank size is 20 Gallons but will be upgrading soon as he's
starting to become larger (about 2" long now).
<He needs a much larger tank, now. Please read here on
It can be caused by a myriad of problems, but the most
commonly-seen issue is water quality.
Oscars are really great, but they make huge messes. You've
got to be able to combat that, with a large enough tank and
enough maintenance. If you don't, this is the issue.>
I had other cichlids (Blood Parrots) that required minimal
attention water change wise, and lived 6+ years with not so much
as a case of Ich,
<Ich is rarely an issue with established fish. By this, I mean
fish which are in a tank, with no other fish added, and Ich
wasn't present before.>
so I did not know that I needed to keep my tank in tip top shape
for my Oscar, so admittedly the water quality was poor. By poor I
mean Nitrates were between 80-160, Nitrites around 1 and I
didn't even test for ammonia.
Since researching HITH and desperately wanting to fix my fish and
never have this occur again, I have purchased a whole arsenal of
<Yes, it's easy to buy stuff. But what of reading? Taking
the time to understand, and fixing the root of the
I bought the meds as mentioned before, I bought a bunch of carbon
filter replacements (I was only changing this around once every
3-4 months) to start doing replacements bi-weekly and I purchased
the "Lunch Box" variety pack of frozen food
(Bloodworms, Veggie and Brine Shrimp variety pack).
<I'm going to start with the following: Buy a larger
aquarium. New filter cartridges don't make up for tiny tanks.
Secondly, read here:
Your carbon filters (likely Hang-On-Back filters) aren't
going to cut it. I'd recommend a 75-gallon aquarium for this
guy, and either a filter or combination of filters which turn the
tank's volume over 10 times per hour.
You're not looking at what the filter is "rated"
for, but the turnover per hour. I see below that you're also
keeping Blood Parrots. I'd recommend a 125 gallon for all of
these fish, in the interest of (hopefully) peacefully
establishing territories and providing ample volume to dilute
That's a large amount of turnover per hour. I run a
180-gallon currently with three canister filters that do the job,
so this is one route you could go. On the other hand, I ran a
freshwater sump on a 125 while my Red-Tailed Catfish's pond
was being built, so that's another option, and it's also
cheaper. You build the sump yourself (search on Google for DIY
sumps) and then add a strong, strong pump. If you can't
afford a larger aquarium, buy a stock pond instead, and fit your
DIY sump to that. There's a lot of research to be done, but a
lot of information exists, and what you'll end up with is a
hybrid of your own ideas and the research you've
I am going to be doing weekly water changes of 25% going
<Try for 75%. You've got to get Nitrates below 20.>
I was a negligent/ignorant Oscar owner but now that I have done
my research I am going to be much, much better.
<That's great, but you're still way behind where you
should be. Your fish needs you to do more.>
With all this said, I am at the end of the external water
treatment and am going to be putting the carbon filter back in
and doing a water change in just a bit. However, upon looking
closely at my Oscar to see any signs of improvement, I noticed
two things, 1. He was 'pooping' a clearish, whitish
stringy type of waste.
It is usually red, like his pellets so I figure this must have
something to do with his current treatment? Does it mean it's
working or not working? He later pooped his normal color.
<I'd keep an eye out. Clear poop can indicate internal
parasites. It could also be an effect of poor water quality and
medication. Let's get one thing clear -- you can medicate
until the cows come home (and your fish dies), or you can get
water quality to where it should be. This is likely the problem,
and medication isn't going to help unless your fish is living
in optimal conditions (Ammonia and Nitrite of zero, Nitrate under
20. If your fish isn't getting better, and you're
medicating as heavily as you indicate above, then I'd stop
with medication (they can affect the biological filter) and just
focus on water quality, and I'd watch his poop.
(I couldn't say that anywhere but here, really.)>
2. I am seeing these tiny, tiny, thread-looking worms floating
all over the place in the water. They appear to be
'swimming' as they sort of curl around and straighten
out, like they are wiggling. They are extremely small and some
appear to be dead. I have never in my life, in 20 years of fish
keeping seen these things in a tank before. Is this the parasite
coming out of my Oscar?
<These "worms" are likely Planaria, and are a result
of overfeeding. I don't mean that everything you feed
isn't going into your Oscar's mouth.
I'm sure it is, because they're basically vacuum
cleaners! I mean that the stuff that comes out of his gills
(almost 50%, I'd say?) and lands on the gravel makes a great
feeding/breeding ground for these critters. Oscars are messy.
Those who love them accept this, and the maintenance that comes
along with them. Start gravel-vac'ing. The Planaria should
diminish once their food supply dwindles. Please read here:
My Oscar has a hole in the center of his head and about 3 smaller
holes below his nose and around his eye. It is definitely HITH.
In addition to this though, one of his pelvic fins seems to be
almost completely gone, like it is being nipped. It seems
<Finrot? Sorry, but anything is possible here. These Nitrate
levels he's living in could cause any manifestation of poor
water quality to, well... manifest. Please begin HUGE water
changes now. This guy is trying to hold out.>
The other fin is fine. On his anal and dorsal fins, he has one
perfectly symmetrical tiny hole. It looks like someone took a
hole punch and punched it. He shares this tank with two baby
blood parrot cichlids for now,
but again will be placed in much larger tank by himself
<Now, please. He's sick. He needs it. If he could speak,
he'd say so. Since he can't, I'll tell you
With that said, does the fin damage seem like it might be
aggression from the other fish (the Blood Parrots fight with each
other and him on occasion), or does it sound like he might also
have fin rot? I am most concerned with the HITH, his fin problems
and those tiny little worms.
I now know nitrites and ammonia should be 0 and nitrates should
be below 24ppm. I have test kits and will be monitoring this on a
regular basis going forward. I feel terrible I did this to him
Any ideas/suggestions? Thank you!! Your site has been extremely
helpful in educating me on how to care for Oscars.
<Katie, please place these fish into a proper environment and
begin proper maintenance. Your problems began there, and the only
answer is there.
Please do write back if you have any more questions.>
Re: Oscar with HITH and little worms? Help please :( --
Thanks so much for your reply. I will update you on the changes
that I have made since your email, but my Oscar is still very
sick. I can't seem to get him better no matter what I do and
it's killing me.
<Oh... let's see if I can help.>
I just bought him is very own 50 gallon tank and removed him from
the old one and placed him in the new tank (I added the product
"Stability" to cycle the tank.
<It's good that you've gotten him larger quarters, but
I'm not really a fan of this product... I've just never
had any real positive experience with it. I tried to cycle a 55
with it a couple of years ago, and after the subsequent ammonia
spike, deemed it useless. I do like "Dr. Tim's
One-And-Only," but it's more difficult to come by in
I felt if I left him in the old tank any longer to let the tank
naturally cycle, that he would have died within a week or so.
<Unfortunately, he may be in the same situation in the new
tank... as it is, basically, not cycled.>
When I first put him in the new tank (with a heater that supports
up to 60 gallons and a Marineland hang on back filter that is
made for up to 80 gallons with 4 carbon filters in it),
<Are you using the rule we discussed earlier... dividing the
filter's gallons-per-hour by tank size, and coming up with a
turnover of at least 8 times the tank's volume per hour? And,
again, I'd like to point out that most HOB filters really
offer very little in the way of biological filtration -- carbon
is pretty much redundant in many aquariums, but what it does do
is provide surface area for bacteria to colonize. When you change
these cartridges, you remove all of that beneficial bacteria.
AquaClear makes a line of HOB filters which provide for all three
types of filtration, but with Oscars, I really think a good,
beefy canister filter is order.>
he was swimming back and forth, seemingly very happy to be able
to finally do some laps without being bothered by other fish.
<Yes, and at this point, the water was likely much, much
cleaner than in his old tank. It was only after he began to make
waste for which there was no method of export that the problems
However he then settled to the bottom and hasn't moved much
since. It has been a week since I put him in his new tank.
Ammonia levels are just barely .25, nitrate is 20 and nitrite is
.5 (nitrate is 20 right out of the tap).
<So, it is not cycled.>
I know nitrite is supposed to be 0 but I can't get it there
without the BioWheel becoming fully established it seems.
<You're right, and Ammonia is also supposed to be
I didn't put in the water conditioner yet to remove chlorine
since my chlorine reading is 0 and I don't want to put too
much stuff in there.
<Yes, but what of Chloramine? This is a product which is in a
lot of people's tap water, but does not evaporate as Chlorine
does. Go ahead and use a product like "Prime" to be
safe... and don't worry about putting it in. It won't
His condition is as follows: His original holes have still not
healed (the first hole being the deepest one right in the center
of his forehead) and he has since developed several new ones
along his head and body. His body seems to be losing scales too,
not sure if this is new holes forming or what. His ragged anal
fin still hasn't grown back nor has the ragged side fin. He
has a hole in his dorsal fin and now near his tail. It just looks
like he is getting worse.
<It sounds like it, too. Again, I can't stress how much
more easily fish succumb to bacterial infection and fungus when
they live in unhealthy conditions. It sounds like you're on
the right track to getting this guy into an environment which
will benefit him, but I worry that the ammonia and nitrite
present will spike if you don't keep a close eye on their
levels and perform frequent, large water changes. I wouldn't
consider this tank cycled, by any means, and that worries me, as
this fish probably can't handle much more.>
He has some cloudiness on the very ragged side fin near his fill
and now the other side fin has some cloudiness on it too near the
gill. I am treating with Melafix only right now to try to repair
his fins from the raggedness and the cloudiness.
<Don't worry about this, as what your fish needs is clean
water and then a real medication.>
I am afraid of over medicating because I know this can stress a
fish so I haven't treated with anything else.
<It can stress him to mis-treat and over-treat, especially if
you use several things at one time.>
The Metronidazole made him very sick. He had a very bad reaction
to it (lethargy, almost like he looks right now) so I don't
want to give him this again.
<The thing about treating fish which live in a poor
environment is that the fish is already weakened. However, if
right now, he's exhibiting the same symptoms as when you
treated with medication, then you can reasonably deduce that his
symptoms did not stem from the medication, but from environment,
I purchased Maracide in case he had Velvet (the cloudiness on his
fins), but I never administered it.
<I think what's going on with his fins is Finrot, but
please read here and see what you think: http://www.wetwebmedia.com/fwsubwebindex/FWFinRot.htm.
The "cloudiness" could be swelling, which then results
in the actual fin erosion, and in the cloudy areas, you're
simply seeing the precursor to the more identifiable symptom of
I'm afraid because I don't know exactly what it is that
he has, or if he has several issues.
<I think he does, but you've got to get his water clean,
and then treat afterward. Please read here:
should get you pointed in the right direction as to how to treat
your fish properly after you determine what's wrong with him.
Since we cannot deduce that his HITH is not caused by poor water
quality, I think it would be wrong, at this point, to begin
treatment for Hexamita. I would probably focus on the other
lesions/erosion of his exterior, and treat with Maracyn. You can
use the table on this page to determine what's available in
your area that would treat his ailments.>
All I know is that nothing is helping. I switched his diet to a
mixture of pellets, frozen brine shrimp, frozen greens (which he
doesn't like at all),
and an occasional rinsed earth worm. He used to go crazy for the
earth worm and then perk right up the next day but in the last
three days he has lost his appetite completely. He won't eat
the earthworm and sucked in only one or two shrimps, only to spit
<He is not feeling well.>
I'm so worried. I have included a picture of him so you can
see his condition, both under 300k in size. You can clearly see
the poor state of his fins as well as all of the terrible holes.
How can I help him any more than I already have? Why isn't he
getting better? I have read that some Oscars "sulk" at
the bottom of the tank after switching to a new tank but he's
not eating which worries me the most.
<He has only been in his new tank one week, and his tank is
mid-cycle, and so he was a sick fish placed into another poor
environment. I would suggest attempting to find some
"seeded" filter media to more quickly cycle this tank,
but with most HOB filters, there's just no place to put it.
You could try and fit some in somewhere, and this would greatly
speed the cycling process. Or, if someone has a cycled HOB
running for a quarantine tank or the like, maybe they would let
you borrow it?>
Although I appreciated your last reply very much and it was very
informative, it didn't arrive until weeks after I wrote
<I honestly have no idea why it took that long. We try to
answer all queries within 24 hours, and I would never have pulled
your e-mail from the inbox unless I could answer it promptly. I
hope this one gets to you faster, but for future reference, you
can find your e-mail on our Daily FAQs page, and there's even
a new link so that you can see the past few days' queries in
case you miss it.>
I'm afraid if it takes that long again, I might lose him.
I'm not trying to be pushy, I'm just desperate.
<I understand, and again, I'm sorry it took so long for
you to receive my reply.>
He is only 6 months old.
<I know he is in bad shape from your descriptions and your
photos. I understand that you feel frustrated, but you must also
understand that the root of his problems in the old tank did not
go away when you placed him in the new tank, and in fact, the
longer he is in this uncycled system, the poorer water quality
will become unless you do the best you can to combat the Ammonia
and Nitrite spikes. You can do this through large, frequent water
changes or attempting to find a way to attach a
"seeded," or cycled filter to the tank, or at the very
least, some established biological media. As I said earlier, I
would attempt to treat with Maracyn for what I think is Finrot...
please do check the page I linked you to confirm my suspicion. I
would not attempt to treat the HITH right now, since one of the
contributing factors for its appearance is poor water quality, so
without getting this fish into cleaner water, you'll never
know if it's going to heal or not. Also, your fish is weak,
and treating with one medication at a time is probably best. Do
be sure to follow the manufacturer's instructions. Again, I
hope this e-mail reaches you in a more timely manner, and please
do write back if you have any questions after reading.>
Re: Oscar with HITH and little worms?
Help please :( -- 8/3/10
Thank you so much for the very fast reply, it is greatly
<You're welcome, and I'm so glad it got to you faster
this time! If it took three weeks every time we wrote, I think
we'd be better off with tin cans and string.>
I am going to do some large water changes to try to combat this.
I also have some cartridges that haven't been changed in a
while as well as a BioWheel that is 2 years old in the tank the
blood parrots live in that I can swap out to help the new tank
become more established.
<This sounds like a good plan. Just make sure not to leave the
Blood Parrots high and dry -- that is, make sure there's
still at least 50% of the media remaining in their tank so that
the colony can quickly make up for the difference.>
I am also going to
purchase a canister filter asap.
<It would probably be a good idea to get this tank good and
established with the filter you have, so that you can use parts
of it to jump-start the new filter. Since canister filters are so
much easier to work with when it comes to media, even taking a
cycled bio-wheel apart and just placing that material (the stiff
fabric stuff) into the canister filter, along with your existing
carbon, would probably do the job. This is one of the reasons I
love my canister filters, though I'm also quite partial to
the AquaClear HOBs -- I've got filters stuffed with
everything from plastic scouring pads to old bio-balls. It really
makes it easy to establish new tanks.>
I will read your link regarding fin rot and purchase some Maracyn
tonight after reading.
I bought the Maracide thinking this was the same thing as Maracyn
but its not, it's malachite green for Ich and velvet.
<Medications can be terribly confusing, which is why I think
that link I sent you with the table is so great. First, you
diagnose, and then, go to the table for proper treatment and
substitute treatments, just in case your local store doesn't
carry a particular one.>
This is why your crew is so helpful to us Oscar owners. Your
knowledge on these little guys is absolutely invaluable.
<I wish your little guy the best, and am glad I could be of
help. Another thing you could do, just to sort of "bulk
up" in the knowledge department, is to read the Oscar pages
in your free time. You'll be amazed at what pieces of
information that you hang on to will happen to be useful in the
Thanks again and I will keep you updated.
<I look forward to hearing about your Oscar's progress.
Please do write back if you have further questions, also.>
Re: Oscar with HITH and little worms? Help
please :( 8/6/10
Yes, that was definitely a typo. I meant to say 1 tablespoon per
5 gallons, so I put in 10 tablespoons since his tank is 50
gallons. These were the instructions on the aquarium salt
<Oh, okay. The aquarium salt people (probably API?) intend the
product to be used as a "tonic" on a daily basis,
which, in reality, does nothing but make them money. It's
when trying to detoxify Nitrite, treat Ich, etc., that one needs
a good recipe for success... both of which are included in that
link, for your future reference.>
I ran out to run an errand and read your email on my cell phone.
I rushed home to do a water change to get rid of all the meds,
but it was too late. I am really sad to report that my Oscar has
<I am so sorry to hear this. He was a lovely fish with really
When my boyfriend came home, Oscar was on his side and hill gills
were fully extended and he called me. I had him do a massive
water change just in case there was anything left in him, but he
has died. I feel horrible.
<You made mistakes, and then did what you could to rectify
them. You have done more than a lot of people would have, and
you've learned a lot. I think that we all have these stories
about the beginning of our fishkeeping days -- whether we
didn't know what cycling was, put the wrong combination of
fishes together, only to find one beaten up, or failed to provide
proper nutrition, etc. In the end, those who stick with it and
learn from what went wrong are the folks who have had tanks set
up for years now with no problems. There are others who refuse to
learn/believe who quickly fizzle out as fishkeepers.>
After I read your email I was considering euthanizing him
humanely so that he didn't have to suffer anymore.
<I suspected this may be necessary after hearing of his color
loss, but I know that you're the only one who can make that
I sat there next to his tank last night just watching him and he
came close to the glass to "sit" next to me and his
eyes were looking right at me. I felt so horrible, I just wanted
to help him. At least he is no longer suffering now.
<I know how you felt. The need to do something, anything, but
feeling powerless... is heart wrenching. It is true that he has
crossed the "rainbow bridge...">
To answer your question from your last response, I did leave the
charcoal filter cartridges in there while treating with the meds
as both of the Mardel products that I was using stated on the
back to leave normal filtering in tact and removing the carbon
was not necessary.
<Ahh, okay. Perhaps these have different "rules,"
but in my experience, it is always necessary to remove carbon. It
just soaks everything up. However, you were right to follow the
. I had just purchased a big box of Maracyn too, for when he got
<Keep it on hand. You may need it at some point in the future.
Just keep an eye on its expiration date.>
I want to thank you so much for all of the advice you have given
me and for the very fast responses when I needed it the most.
This is the end result I was so desperately trying to avoid but
at least now I know what it means to be an Oscar owner and
exactly what it takes to keep these little guys healthy. I just
wish I knew all of this before he even got sick. I'm no
longer an ignorant Oscar owner.
<Then, at this stage in the game, you have gotten further than
many. I'm sorry to hear of the loss of your little guy, but
do hope that you'll try again. The next Oscar can look
forward to having a loving owner who is indeed educated on his
Thanks again for everything, Katie
<You're welcome, Katie. I wish you the best in fishkeeping
(and other) efforts. --Melinda>
Re: Update on my Oscar; Was: Oscar with HITH and little worms?
Help please :( 8/6/10
I have been doing large (50%) water changes in the new 50 gallon
tank daily since your last email. At that time ammonia was high
.25 and then nearly .50 just hours later. I added media from my
already established tank (replaced with a new charcoal pad for
now as all levels are reading healthy in that tank, but still
keeping watch on it). Literally the next day the ammonia levels
are now at 0 and nitrite suddenly spiked to 3.0.
<This is a good sign for the cycle, but not much better for
I know this is part of the cycling, but fearing this would cause
even more stress I added aquarium salt (5 tablespoons per gallon
so 10 tablespoons) which I heard helps fish cope with
<I'm not sure about your math here (perhaps a typo?)
because I was under the impression that this tank is fifty
gallons, and besides, five tablespoons per gallon is a TON of
salt! Using the dosage indicated within this article which
detoxifies nitrite: http://www.wetwebmedia.com/fwsubwebindex/SaltUseFWArtNeale.htm,
you may want to adjust what you've added here. I hesitate to
work with the numbers you gave me, because I'm not sure that
they're totally correct, but the information you need is in
the above-linked article.>
and I also started treating with Maracyn and Maracide (prior to
adding the meds I did a huge water change, 60% and got the
nitrites down to a little less than 2.0). The label says it's
okay to use together. I started with the Maracide first because
he appeared to be developing a case of Ich in addition to
<Salt kills Ich. Please read this in the link above. You
really need to be careful, because you're sort of
over-medicating here, and the use of the Maracide, even if your
fish had Ich, was needless. The salt would have taken care of
your problem. I worry that this fish is very sick, and now
he's being subjected to a cocktail of various medications and
salt, and there's no need to subject him to more than
The very next day all the Ich spots were gone and amazingly, his
holes from the HITH seem to be getting much better!
<What you saw was likely not Ich, but in any case, it's
good that it's gone. Good news on the HITH, as well, but I
have to say that this is the fastest recovery from HITH I have
ever heard of!>
Some of them don't appear to be holes anymore, just blemishes
and the existing holes edges have all taken on a huge of black. I
thought I read on here somewhere that this is the first sign of
the holes healing. Anyway, I started on the Maracyn today but
notice no signs of improvement yet. In fact, despite the positive
appearance of his holes he is still extremely lethargic, his tail
is twitching still every 15 seconds or so and more disturbing,
his coloring has changed. He is noticeably losing all of his
coloring, turning a grayish shade with no more deep black or
<Your fish may not make it. It seems that the larger the fish,
the longer they can hang on, and the easier it is to get them
through treatment. I would like for you to read here: http://www.wetwebmedia.com/euthanasia.htm.
I am not advising you to euthanize your fish immediately by any
means, but it's better that you have products on hand to end
his suffering if the time comes. Your fish is still quite small,
in fact, smaller than he should be, likely due to the high level
of Nitrates which existed in his first tank. By all means,
continue to try and save him, but do be knowledgeable about
humane methods of euthanasia if the time comes that it is
days. At the store I noticed there was another medication called
Maracyn Two and I wasn't sure which one was the proper one to
purchase. Maracyn Two said it's to be used for negative
bacteria and is to be used on fish who won't eat. I almost
bought it for this factor alone because that's what worries
me the most, but I wanted to make sure I followed your
<I would not add another medication. My advice to you was to
first establish the cycle by doing what you did, which was adding
seeded media. Then once water quality was up to par, to treat for
the Finrot and then see if the holes began to heal on their own
(indicating HITH was caused by poor water quality). If it
didn't heal, then I'd treat for Hexamita. However, this
fish is now being subjected to a lot of medication, and his water
still isn't clean. I totally understand that you want to help
him, but I feel he may be slipping away.>
Do you think it's too late for my Oscar? Have you ever seen
an Oscar actually come back and get healthy after he has stopped
eating for days, sits at the bottom looking gray and noticeably
thinner, and tail twitching?
<It may be too late for him. Not because he hasn't eaten,
because fish can go a couple of weeks without eating. I worry
because he is obviously stressed and he has been sick for a long
Now that I'm medicating, I'm not sure when to perform the
water changes or how often?
<That's sort of the problem. You can use the salt in the
correct amount and detoxify Nitrite, which would negate the need
for water changes. If you choose not to use the salt, then you
would have to do the water changes, in order to remove Nitrite,
but then you'll need to replace medication which has been
taken out. What you do is up to you, but I'd probably use the
salt in order to avoid accidentally over- or under-medicating due
to frequent, large water changes.>
Will the salt help him tolerate the nitrite spike until the tank
is fully cycled?
<Yes, but do read the article I linked you to above and adjust
the levels in the tank so that they match what's listed in
It should be noted that nitrites have held steady at 2.0 which I
know is still very toxic, but nitrates are now starting to show
up at around 10ppm and ammonia remains at 0. I'm hoping that
adding the filter media from the other tank really did help jump
start the cycle and perhaps its almost complete.
<It obviously helped, and that's very good.>
It's not looking good.
<I agree. I'm sorry.>
This is my first Oscar and I have learned so much about what not
to do and unfortunately at my fish's expense. That's the
worst part of all this. Having never owned an Oscar before,
I'm not sure how hardy they are and if they can really come
back from this state but I am trying like he*l.
<They are quite hardy fish, but this fish's small size,
the duration of his illness, the lack of a cycled tank, the
mixture of medications, etc. do not look good for him. Have you
removed the carbon from the filter? If not, it is likely that
this medication has simply been absorbed by the carbon. The salt
wouldn't have been, though, so even if carbon is present, the
salt would still be in the water. I would, first, determine how
much more salt you need by re-examining the first dosage you used
then using the article. Then, I would not add any further
medications. I'd allow the tank to complete its cycle and
give the medications time to work. I know that this process is
frustrating, because all you want is to look over and see your
fish acting normally and healthy, but unfortunately, it took him
a while to get sick, and it's going to take a while for him
to get better. He may not pull through. If his condition
continues to worsen and he decide to euthanize, you have that
information above, as well. I'm sorry I can't give you
any more encouraging news, because I can tell that you really do
want to do right by this fish and heal him.>
Thanks again in advance, Katie
<You're welcome, Katie. I wish you and your fish the best,
and please do write back if you have any more
ps. Canister filter is in the mail on the way to my house. I hope
it makes it in time. :(
<As I said in a previous e-mail, I do not think that now is
the time to switch filters on this guy. I really would allow this
filter which is on the tank currently to become established.
After he gets better, you will need some heavy filtration to keep
up with his growth/messiness (!!), but now, the real concern is
fixing him, and the best way to do that is get the tank cycled,
medicate properly, and wait.>
Re: Oscar with HITH and little worms? Help please :(
Thank you for the kind words. It was very hard to let him go. I
have kept fish my whole life and blood parrots exclusively for
the last 8 years so I know it's easy to become attached to
fish over time, but I never knew I'd get attached so quickly
to my Oscar.
<It's so easy to get attached to such great fish.>
He just had an awesome personality and was very interesting to
watch. He was also very engaging the way he would specifically
look directly at your eyes. Like you said, he had beautiful
colors and I'm going to miss watching him every day. I feel
terrible that I lost him so young. It's possible that he was
sick right from the store and the symptoms hadn't progressed
until I'd already had him a few months but who knows.
I'm sure it was the water quality as I was only doing water
changes about once a month at that time but my blood parrots are
healthy as horses, it's hard to say. Either way, we are going
to try again with a new baby Oscar and hopefully he will live a
long healthy life.
<Good! I'm sure you'll do well.>
Just so you know your words really made me feel a lot better
yesterday when I was pretty upset. You were gracious, honest and
understanding but mostly you were right, so I wanted to thank
you. I guess everyone learns the hard way sometimes.
<I'm glad I could be of help to you. On the whole, owning
pets is really bittersweet -- unless it's a Sulcata Tortoise,
chances are, you're going to outlive your pet. Those of us
with hearts big enough to take in and love animals also suffer
huge heartbreak when they go, whether their death is timely or
Take care and I'll email again if I have any questions
regarding our soon to be new Oscar (once I'm positive the
tank has cycled). I'll miss my buddy.
<Good luck and I'm glad you're not giving up!>