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FAQs about Red Calcareous and Coralline Algae Compatibility & Control 

Related Articles: Coralline Marine Algae, Red Algae in GeneralAvoiding Algae Problems in Marine System, Algae Control, Marine Maintenance, Nutrient Control and Export, Marine Scavengers, Snails, Hermit Crabs, Mithrax/Emerald Green Crabs, Sea Urchins, Blennies, Algae Filters, Ctenochaetus/Bristle Mouth Tangs, Zebrasoma/Sailfin Tangs, Skimmers, Skimmer Selection, Marine Algae, Coralline Algae, Green Algae, Brown Algae, Blue-Green "Algae"/(Cyanobacteria)Diatoms, Brown Algae

Related FAQs: Coralline Algae 1Coralline Algae 2, Coralline Algae 3, Coralline Algae 4, Coralline Algae Identification, Coralline Algae Behavior, Coralline Algae Compatibility/Control, Coralline Algae Selection, Coralline Algae Systems, Coralline Algae Nutrition, Coralline Algae Disease, Coralline Algae Reproduction/Propagation, Red Algae in General, Red Algae 2, Red Algae 3, Red Algae Identification, Red Algae Behavior, Red Algae Compatibility, Red Algae Selection, Red Algae Systems, Red Algae Nutrition, Red Algae Disease, Red Algae Reproduction/Propagation, Marine Macro-Algae, Use in AquariumsMarine Algae ID 1, Marine Algae ID 2, Marine Algae Control FAQs II, Marine Algaecide Use, Nutrient Limitation, Marine Algae Eaters, Culturing Macro-Algae; Controlling: BGA/Cyano, Red/Encrusting Algae, Green Algae, Brown/Diatom Algae

Bristlemouth Tangs can consume a good deal of Coralline Algae.  Ctenochaetus cyanocheilus Randall & Clements 2001

New Print and eBook on Amazon

Marine Aquarium Algae Control

by Robert (Bob) Fenner

LA Fishguys Episode 146‏, Scraping Coraline Algae      9/1/15
Hi There,
The newest LA Fishguys episode is out, Episode 146 Scraping Coraline Algae
Your promotion is in Part Two
<Thanks Jimbo! B>
Part One https://youtu.be/talTCHREkFA
Part Two https://youtu.be/00LIWvsiqYI
Part Three https://youtu.be/QS2chfiNpyo
Jim Stime, Jr
Aquarium Design - Installation and Maintenance
Midwater Systems - JELLIQUARIUM Jellyfish Display Systems
MyFishTank.com - Acrylic Aquariums, Stands and Canopies
LA Fishguys - Aquarium Reality Television

How to kill coralline? 3/5/11
Hi Crew!
It's been awhile - things very even-keeled ;) But... Is there something I can add to kill the coralline? Naturally, I need to be mindful of the other critters. There's an incredible amount of information on WWM about growing coralline (in decorator colors, too) but there is nothing I have found on how to kill it. If I had known it would get like this, I would have bought dry rock, a few bottles of pods, and then picked up what interesting life I could in my travels.
I've got this layer of coralline that is so thick I have to bust it off the rock now and then. In places, it's about 3/16 inch thick and even grows off the rocks like fungus on a tree. I've got 2 pics here so you can see what I mean.
<It is growing quite well.>
In the last 2 years, I have dismantled my reef not less than 6 times to literally chisel the coralline off the rock. This is a pain in the neck and getting more difficult to do as I add more corals.
<This may help curb it, the coral's use of calcium may help control the coralline's growth.>
Also, because there is an incredible abundance of life in or on the rock, I can't soak it in vinegar or fresh water. I have a few chunks where I got lucky and picked up some Chitons, a bunch of tunicates, a few sponges, and a neon green octocoral colony that is growing ever so slowly.
Water quality: SG=1.025, pH=8.2, T=80F, NH3,NO2,PO4=0, Ca=420, dKH=11,
NO3=10-15. The only thing I add besides salt (Instant Ocean) is vodka.
If Ca goes low, I'll add some, but that happens so rarely I'm still working on a bottle I bought 2 years ago. I have just under 5W/g for 12 hours in a full-length 4 bulb PC fixture. Two bulbs are 10,000K and the other two are split 420/460nm. People have suggested Asterina stars (of which I have about a dozen) and urchins.
<Urchins are the only thing I know of that will consistently eat coralline, it takes an especially tough mouth to eat that stuff, which the urchin has.>
I don't know about urchins - I'm not too keen on having a Tuxedo parading around with my frag plugs on his back or a long spine the size of a softball trying to squeeze himself between all the rocks.
<They do have their issues of which you are aware, the tuxedo would be less problematic most likely.>
I have a turbo snail that can barely handle that and while he's big for a turbo, he's smaller than an urchin's body without the spines.
<Both are like bulldozers at times.>
I appreciate any help you can give me on this.
<Unfortunately for you what is good for corals is good for coralline, but the plus side is that the coralline's growth indicates your corals should do well. See here for more http://www.wetwebmedia.com/corlinecompfaqs.htm
Re: How to kill coralline? 3/6/11

Hi Chris-
Thanks for the speedy reply. I think I'm going to go get a long-spine today.
<Just be aware how big they get. http://www.wetwebmedia.com/urchins.htm 
Corals are doing well, thanks, even that octocoral, to my surprise.
Maybe, if I can curb the coralline with an urchin, the corals will do better
Have a great weekend,
<You too.>
Re: How to kill coralline? 3/6/11
Thanks, Chris, but inasmuch as it seemed a snap decision, I did my research on this.
<Ah, very good.>
I got a D. antillarum and made sure to find one that had deeply defined white bands. The disk is only about an inch, and overall it's just a bit bigger than a softball. Wish I could have found one with a blue eye, but this one has the traditional orange. Still, it's a beauty and displays well defined electric blue lightning. So far, he's been pussyfooting over my Zoa, and he's already learned to steer clear of the clown nest ;)
<Sounds nice.>

Worms and Corallines, ScottT's go  -- 7/7/10
Hi Crew-
<Hi Sal!>
Hope everyone's well and had a great weekend! As you've all been so helpful in the past, I turn to the masters once again. I've got two problems, and I hope you can help with at least one. I've got about 80 pounds of LR in a
55, sand bed, inverts, corals, and some fish (including a pair of successfully breeding A. ocellaris).
<Great work!>
I've got a large, persistent population of bristle worms which I have been trapping, etc. for months. They keep returning. I've got both the Hawaiian Fire and the grey varieties. Some of those get quite large, and I once pulled one out that was almost 10 inches long. At my wit's end, I'm seriously considering removing all the rock with nothing on it I want to keep and soaking it in chlorinated tap water (bleach added?) for a few hours or a day while I sift through the entire sand bed to remove anything in there that's not sand. Is there a better way to kill these things
*permanently* than to uproot the entire tank? Also, how do I treat the rock that may contain corals, polyps, Chitons, and other life I want to keep?
<Have you considered embracing them? They do a nice clean up job. I personally love them.>
The other problem is, I am growing a *thick* coat of corallines all over everything. I have not added calcium to my reef tank in over 5 months, and the coralline grows about 1/4 inch thick in that time. Short of the above method which kills the worms, is there a way to stop it from growing? It's quite annoying, as it is encrusting all my polyps and must be broken off with a forceps at least once per month or the polyps will get strangled.
If I add any calcium at all besides what is available in the salt mix (Instant Ocean) I must free the polyps every week.
<I'm putting this back for someone who knows more to respond. You should get two replies.>
Much appreciated,
<Scott T.>

Worms and Corallines, RMF's go  -- 7/7/10
Hi Crew-
Hope everyone's well and had a great weekend! As you've all been so helpful in the past, I turn to the masters once again. I've got two problems, and I hope you can help with at least one. I've got about 80 pounds of LR in a 55, sand bed, inverts, corals, and some fish (including a pair of successfully breeding A. ocellaris).
I've got a large, persistent population of bristle worms which I have been trapping, etc. for months. They keep returning.
<As they are wont to do>
I've got both the Hawaiian Fire and the grey varieties. Some of those get quite large, and I once pulled one out that was almost 10 inches long. At my wit's end, I'm seriously considering removing all the rock with nothing on it I want to keep and soaking it in chlorinated tap water (bleach added?)
<Mmm, I wouldn't do this... likely some individuals would be reintroduced with the rock>
for a few hours or a day while I sift through the entire sand bed to remove anything in there that's not sand. Is there a better way to kill these things *permanently* than to uproot the entire tank?
<... Predators, trapping... Read here:
and the linked files above>
Also, how do I treat the rock that may contain corals, polyps, Chitons, and other life I want to keep?
<... can't really. There are no processes, chemical treatments that are strictly harmful only to Errantiate Polychaetes>
The other problem is, I am growing a *thick* coat of corallines all over everything. I have not added calcium to my reef tank in over 5 months, and the coralline grows about 1/4 inch thick in that time. Short of the above method which kills the worms, is there a way to stop it from growing?
<... Read here: http://wetwebmedia.com/corlinecompfaqs.htm
It's quite annoying, as it is encrusting all my polyps and must be broken off with a forceps at least once per month or the polyps will get strangled.
If I add any calcium at all besides what is available in the salt mix (Instant Ocean) I must free the polyps every week.
Much appreciated,
<Please learn to/use the search tool, indices. More light and adding Greens, Red Algae macrophytic species will likely outcompete the Coralline/s. Bob Fenner>

Re: Worms and Corallines -- 7/7/10
Hi Bob-
<Howdy Sal>
I replied to Scott, but our emails crossed. I did use the search tool, thanks for the reminder, but the trouble is, I have a lot of worms. Also, I mostly catch Nassarius snails by their siphons if I use a trap.
<Try different trap/s, bait...>
Meanwhile, the *hundreds* of worms can't get trapped because the snails have blocked the trap entrances and stolen the bait.
<Heeee! Maybe move the snails elsewhere while hunting Vermes>
Any ideas on making that a more efficient task?
<None that isn't archived. B>
Re: Worms and Corallines -- 7/7/10
I'll try moving the snails. First, I got to catch' em ;)
<Reads like your present trap/ping should do it here. B>
Re: Worms and Corallines, ScottT's go  -- 7/7/10

Hi Scott-
<Nice to hear from you Sal.>
Yes, I have embraced the worms (Bob's trained me well!) but they're hunting down my snails and corals. I have a nice chunk of base rock that came with four ribbon worms. They do a great job of cleaning up and don't bother any of the more desirable animals. But the bristles are getting out of control. Mostly, it's the large grey ones that are trouble, so I try to pick or siphon them out when I can. They are so bothersome that some of my mushrooms have detached themselves from their rocks and are riding the currents to escape. I don't know if they are attacking the mushrooms or if they are just foraging and irritating them -- but there's an exodus in action. When they land, the 'Shrooms look good, open fully, and appear to be fine. Some of them reattach quickly, others have waited for better locations, I guess.
<I understand. I'm glad Bob could respond to that.>
The polyps have it worse, I think. I bought a frag with over 50 little stars and about 30 clove polyps. All the stars got strangled, and all but 8 cloves died from the coralline crust. I scraped and chiseled off a lot of coralline about 6 months ago, and divided the cloves. One frag is up to 8 and the other has about 12 polyps now, but every time they make progress, the coralline covers their feet and makes tight girdles. It actually closes up some of the crevices and holes in the rock, and sometimes *entirely* blocks the intake screens on my power heads. I think this is more important than the worm problem.
I really need help with this. I appreciate any you can offer.
<I scoured the FAQs about this issue.
http://www.wetwebmedia.com/corlalgfaqs3.htm . Most people have the opposite problem, not enough coralline. There were a good handful of people who did have the same problem as you though. None of the Crew who responded to those emails had any miracle method. Coralline needs the same things as your corals to grow. Scrape off power heads, and soak in vinegar. Remove rocks that have it, but no corals and sterilize them.
Probably just letting it dry for a week. Shake it in freshwater, then seed it externally to the display a while before adding it back. I suppose to slow its growth, make the tank less hospitable to growth in general? Lower light, lower nutrients. This won't help the corals though. How about this idea. Attach corals large enough to the cleaned rock so that the rock is shaded by coral. Ones in the family Euphylliidae come to mind. Then the coral should be able to out-compete the coraline? Clearly I also have no real advice, sorry.>
<Tell us if you find a better solution, Scott T.>
PS - I found the perfect "tweak" for the clown fry situation. I'm up to near 100% hatch rate and about 60% survival. Yep, I'm still doing that freshwater tried and true stuff, but it all works very well ;)
<Great work! Your survival rate sounds good also. I spent a bit of time recently with some clown breeding pioneers. 60% overall is very acceptable.>

Powerhead vs. coralline- Coralline Remover 4/29/08 Hello to the actual "lifesaver"! <Hi. Yunachin here.> Please tell me an accurate way how to clean coralline off of power heads and in-out takes. Does vinegar really works? Is that safe for reef? Your help is appreciated! <Yes, you can use vinegar to remove the excess coralline on your pumps. Remove them and give them a good soak for a couple of hours or even over night. Then give them a good rinsing with clean water to remove any vinegar before placing them back in your tank. An old credit card can also help scrape algae off of surfaces on your tank. --Yunachin> Sonny

Battling unbelievable coralline algae growth, reading   10/19/07 Dear Crew, <Jaime> I have a bit of an issue, and was wanting to get someone else's take on the matter. I've got a small reef tank, and have been battling unbelievable coralline algae growth for the last year or so. It's getting to the point that the coralline will cover 70% of the sides, and crusts up the sand in a little over two weeks time. It is just outrageous. I scrape the sides, then siphon the sand, then do my 30% water change about every two to three weeks. I tried doing water changes more often, (once a week) but didn't seem to slow the process down at all, so I've gone back to every 2-3 weeks. <You do understand what drives such growth, preponderance? A lack of lighting, overabundant biomineral and alkalinity, a paucity of competing photosynthates, predators...> I've also switched from reef crystals to instant ocean to reduce the amount of nutrients in the tank. About my setup- I have a 12 gallon nano cube with about 15 lbs live rock. Once ocellaris clown fish, lots of misc snails, 1 Cynarina, pink pom-pom xenia at the top of the tank that are almost out of control (I should have known better than to put in tank, but they were so fascinating to watch!), and some hitch hiker corals- 3 2" toadstool leathers, 1 1" finger leather, and a 2" mushroom. <Mmm, what you really need, and likely want, is a much larger system> These hitchhikers are going to a new home sometime in the near future. I currently run about 2 tablespoons of charcoal changed w/ water changes, a small sponge rinsed weekly, tank temp is at 80 degrees f, and spg is 1.026. Nitrates- 0, nitrites- 0, ammonia- 0, and I don't do any dosing or any other additives. I feed the fish a small amount twice a day, 3-4 days a week formula 1 flakes, frozen formula 2, and some krill. The Cynarina gets krill or shrimp or salmon, or whatever other uncooked seafood I have in the freezer once a week. I completely switched out the sand about 6 months ago, because the old sand was permanently purple. Now the new sand looks awful, too. I don't mind scraping the sides, but the purple sand is too much. What would you do if you were in my shoes? <Check the water quality, add some purposeful macro-algae... Gracilaria, Chaetomorpha... attach a sump/refugium with a DSB, get a bigger tank...> Go bare bottomed? (In the tank, I mean. Not around town or anything!) I always hear other reefers wanting to know how to grow coralline algae faster, so I feel kind of bad complaining. But I really want white, pretty sand. Not yucky purple sand. Thanks in advance! Jaime <Please read here: http://www.wetwebmedia.com/corlinecompfaqs.htm and the linked files above. Bob Fenner>

How to reduce Coralline Algae?  - 9/3/07 I have an overabundance of Coralline Algae. I realize this is contradictory and most likely blaspheme in the salt-water aquatic world but nevertheless it is true. What can I do to reduce the growth? <Nothing that wouldn't also inhibit your coral growth.> 90 AGA tank up for 18 months. 2 ea. Tunze 6055, Euro-Reef Skimmer, 30 gallon sump, 2 ea. 150 watt 10K halides on for 7 hours, 2 ea. 95 watt actinic on for 9 hours, 1 hour before and after the MH. I dose 2 part 24/7 with a medical dosing unit. Calcium is 370, temp 79, Alkalinity is 3.1 meq/l, Magnesium is 1325, 2 ea.  Plate corals, a Bubble coral, a Brain coral, a Candycane coral, a Montipora coral, 12 large Frogspawn, a Hydnophora coral, GSP coral. Fish livestock consists of 2 ea. Clownfish and 1 Niger Triggerfish. My goal is to reduce the Coralline while still not affecting the Corals. <Your corals could tolerate a calcium level as low as 350ppm. But the coralline might still thrive even with calcium at 350ppm. Your alkalinity is right where it should be. There are urchins which eat coralline algae. But these urchins might not graze where you want them to graze and some are suspected of actually stimulating even more coralline growth by producing "chips" of coralline that can start growing elsewhere in the tank.> I don't mind slow growing corals. <Hmm... you should mind if your corals are growing more slowly than they should be. If the coralline is bothering you because it's on your glass, you can always scrape it off. Sorry, but I don't think there's much else you can do without potentially harming everything else in your tank. After all, the reason coralline is thought of as a "good sign" is because all the conditions which are ideal for a reef tank are also ideal for coralline algae. So I guess you'll just have to suffer the consequences of having a healthy tank. :-)> Thanks in advance for your help. Regards, Pat M. <De nada, Sara M.>

Red Bubble Algae w/ Orange Glow/Coloring  -- 07/01/07 Hey WWM, My tank has had a red bubble algae outbreak, and I am currently in the process of removing it by removing the live rock from the tank in a separate bucket, <Mmm... not a useful approach... Need to discern, address the root cause/s allowing this proliferation...> and removing the bubbled colonies with a toothbrush by scraping them off. Hopefully this is the best way, since it is not happening in my tank and I am limited the spore amount, <Only takes one...> with exceptions to some sticking to my LR. Back to my question. I happened to notice then when I put only my actinic lights on, some of the algae has orange dots or coloring on them that shines noticeable in the tank. <Yes... neat!> I also noticed there was an orange color on a part of my live rock, but it disappeared after a week. What is this? Is it even something I should need to worry about? Thanks Joe <Mmm, a sort of bioluminescence... Not to worry... but to enjoy, appreciate... Do read here: http://www.wetwebmedia.com/marine/maintenance/index.htm scroll down to the (aptly) green "Algae" tray... Bob Fenner>

PURPLE-UP for Coralline Growth? - Thumb's down... 02/22/07 Anyone have any info about this product by CaribSea? <<Have seen/used...don't waste your money mate>> I have a FOWLR and would like to increase the amount of coralline algae...... <<Then look to providing balance to alkalinity/calcium/magnesium.  Obtaining some "seed" material in the form of coralline scrapings from fellow hobbyists/LFS can help too>> Is this product safe and does it work.....? <<Not in my opinion>> I have some very rare fish and do not want to introduce anything that may harm them... <<I have read and seen anecdotal proof that calcium polygluconate can be helpful to "jumpstart" coralline growth.  Seachem makes such a product and if used as directed it should pose no harm to your fish>> Thanks, Craig Smith <<Happy to share.  Eric Russell>>

Turbo snail diet = microalgae   12/28/06 Hello crew! <Hi Michael, Mich with you today.> I just started with saltwater about 3 months ago, now it seems all my time and money is devoted to it! <Yes, welcome to the obsession.> Your website has proved to be an invaluable resource to my new hobby! <A terrific tool, we hope you find it most useful.> My question is, will turbo snails eat my coralline growth on my live rock? <No.  Urchins are known for this.> or do they mainly stick to the looser material? <Turbos typically graze on microalgae, often on the glass as well as the rock.> Thank you so much for all the help you've provided me with!! <Welcome!  Glad to hear this!  -Mich> -Michael Bernd's Coralline >Hola Marina. como estas usted? >>Soy bien, muy bien. I've been consulting with James, another crewmember regarding your issues with the lack of coralline growth and loss of coralline already on rock you've collected, and I'm going to try to condense all correspondence as best I can. One of the things he wondered about, along with lighting, was whether or not you have urchins, as some do eat coralline. >My lights are: 1 x 250 W MH 10K; 4 x 65 W PC Actinic and 50/50; 1 x 96 W PC 50/50. The MH is on 9 hours a day and the PC's 12 hours. >>Ok, here's an excerpt of our discussion.. "You don't need the high intensity as for corals but I would say at least 3 watts per gallon. I think SeaChem's liquid calcium is excellent for growing coralline. It is just an additive, it really doesn't raise the calcium more than 10mg/l, but the gluconate base seems to do wonders for coralline growth. He won't see overnight results, but if he uses it religiously for a month and a half to two months it will amaze him. I experimented with a tank of rock with no coralline, just added a small rock as seed and in two months time all the rocks had growth on them using the reef calcium. Kent's liquid calcium is not gluconate base so I'm not so sure the results would be there. Anthony uses this also and he swears by it. I've [also] heard from several sources that some actinic is better for growing coralline. If he had 50/50 I think he would be OK. I'm kind of wondering what kind of salt mix he is using in that area, along with the age of the lamps. I would [again] suggest the use of the SeaChem liquid calcium. Just sounds to me like there is not enough elements in his water that the coralline needs to grow as long as his lighting is putting out the Kelvin temp it is supposed to. " >>So, I don't believe that lighting is your issue, although he does point out that the age of the bulbs is a factor in the quality of light (from a PAR standpoint). >Here are some of my tank's parameters, taken at 10 a.m. this morning. Calcium 450 >>Good. >Alkalinity 6 meq/l >>I'm not positive, but if I've calculated correctly that is a very high degree of alkalinity. Is there a possibility of switching to natural seawater (filtered, sterilized)? >pH 8.0, spec grav. 1.024 >>Those are well within natural ranges. >I service the Magnum 350 canister filter every 4-6 weeks. I fill it with carbon and de-nitrate. Sometimes also Phosguard. >>Are you getting phosphate/phosphorous readings? If so, the Phosguard is good to use, if not, I wouldn't spend the money. Again, I'm going to strongly suggest looking into setting up an inexpensive refugium my friend. >All my pump intakes have foam pre-filters which I clean twice a week. I make a 20 % water change every 4 weeks. I can't do it more often because of uncertain salt supplies. >>All that water around you... > My fish are: 1 fox face, 1 hippo tang, 1 yellow tang, 2 yellow tail blue demoiselles, 1 dotty back, 1 neon goby, 1 ocellaris clown, 1 Clark's clown. > As for corals: several Ricordeas, mushrooms, some SPS, 1 bubble tip anemone, 1 Condylactis, 1 corkscrew anemone. About 50 blue legged hermits crabs, several emerald crabs and some brittle stars. >>Do watch the brittle stars for their fishing habits, and do be careful with the mix of anemones, and especially the fire coral! (Oddly enough, I accidentally brushed against some in Bali last year, did nothing to me..). >The SPS are fragments that I brought from the Islands here. They are brain coral, Fire coral, Favia, mustard head. 1 Sea fan, some hydroids that came on the rocks that I collected. Those are the ones that I could identify. Have a nice Sunday, what's left of it. Saludos, Bernd >>Yesterday was cold and rainy, we also had a nice power outage in the morning. Hail overnight, and in the morning as well, and we had to fire up the wood burning stove for the first time in at LEAST a month! I much preferred last weekend, mid-70s, SUNNY, gorgeous. It will be here again! In any event, the odd bit that I can see is that alkalinity reading, which as I mentioned does seem high. Unfortunately, this is the extent to which I can help, beyond this I'm probably going to boot you to other crewmembers more well-versed in coralline troubles. My problem is that I've never HAD a problem, and so have never had to solve it, always using seawater in the past. You may wish to enquire on some of the better reefing bulletin boards, Reefs.org, reefcentral.com, et al, for more input. Saludos, Marina 

Follow-up re: Bernd's Coralline >Hola, Marina. Thank You for Your exhaustive reply. >>Buenos dias, Bernd, es de nada. >I know I have at least one small (thumbnail size) sea urchin in the tank. I had some bigger ones but took them out. >>Well, not all species eat coralline, but James did bring it up, so I thought it worth mentioning. >As for my salt mix, I use Kent or Instant Ocean, whatever I can get. You mention all the saltwater around me, but I live on the mainland coast and the sea water here is too contaminated with run off from the mountains and rivers, to use it in a tank. >>Ah, claro. >I change my PC's every 12-18 month. Also due to short supply. You don't know how it is when You have no access to anything. >>Living where I currently am (Sierra Nevada mountains of California), I'm getting an idea.  >The only store we have in the whole country that has anything marine is too scared to buy expensive equipment and store it. >>Not *quite* that bad here, I do have internet orders, can drive to Stockton or Sacramento if need be. >So we have to make do with what we can get. I depend on visitors that come and I can convince them that a powerhead or protein skimmer is more important in their suitcase than underwear. >>Oh my, that IS a tough sell! >I have ordered the Seachem Reef Calcium, let's hope that I get the right one. Sometimes they send me products from a different brand. >>Am curious, who "they"? Do you have troubles getting internet suppliers to send to Honduras? I'm wondering if going via Brazil or Mexico might garner more reliable results. >Anyway, I am in Your debt and if Your travels ever bring You in this region please don't hesitate to mail me first and I will give You all the info how to contact me and I will show You this lovely country. >>That would be my great pleasure, Bernd. My fiancé' had purchased some land en Belize, but is going to let his ex-wife keep it. Too bad, is also close to Costa Rica, my family (en Puerto Rico) has friends there as well. >I will save the "Mangowitz" for Anthony or Bob, though. Saludos, Bernd >>Understood, my friend. >P.S. Su español es perfecto. Mejor que el mio. >>Better than yours? You are too kind (and a good fibber). It's all I can do to keep up with basic syntax! Take care, Marina 

- Purple Haze - Bob, <JasonC today.> I have enclosed an old question I found while trying to find the answer to my question.  Tom has the exact same problem I have, my tank is being overran with coralline algae.  I don't add any calcium. I don't really want to see encrusting green algae either, can you tell me what the encrusting red algae eaters are? <Urchins... I'd look for a tuxedo urchin.> I have a pencil urchin, he's been in my tank for about 11 months, he eats little spots but my real problem is the back of my tank. Any ideas? <Learn to enjoy it - I doubt there's a reef on the planet [including cold water ones] where coralline isn't prevalent. It's an artifact of good tank keeping. You could scrape the back wall with a razor blade or appropriate scraper if this is an acrylic tank but this always seems to bring on more coralline. As Bob stated in his earlier reply, many folks would kill to have this problem.>   Thanks so much! I enjoy your site ever so much! Amy <Cheers, J -- >

Glass or Acrylic Tank and Coralline Algae  9/3/05 Dear Crew, <<Hello Bob - Ted here>> I am planning an upgrade of my current reef from 300 gal (96x30x24) to 500 gal (108x42x26).<<Excellent>> The custom shops I have been talking to can do either glass or acrylic, but seem to prefer acrylic.  Have you had any experience removing coralline and other calcareous algae from acrylic panels?<<Yes. Frequent cleaning will prevent coralline from becoming a problem. And yes, acrylic is easier to scratch when you have to scrape the coralline off so stay ahead of the coralline growth>>  My fear is that I will buy the tank and in four or five years the viewing panels will be ruined from all the scraping to remove the algae.<<Badly scratched acrylic can be polished. Please see this link for information about tank materials http://www.wetwebmedia.com/tksstds.htm>> Thanks, Bob McCook <<You're welcome and good luck with the upgrade - Ted>>

Coralline Overgrowth    3/17/06 I have a 100 gallon sps reef that is thriving and everything is growing very quickly including the coralline algae. I am away at college and my family has let the coralline algae build up. What is the best way of removing coralline from the acrylic? I don't want to scratch it but in the past the only thing that worked even a little bit was a stainless steal blade, which leaves small scratches. I have used my Magfloat, a cleaning pad, a Kent marine algae scraper, and a credit card with no results. Any advice besides not letting it build up in the first place, which is probably the best thing.  <You have answered your own question.  You are using tools I would recommend, all but the stainless blade.  James (Salty Dog)>

Marine Algae; Still Frustrating You After Death  - 04/19/06 Hi <Hello Simon.> I have decided to retire from my salt water hobby and move into fresh water. <I'm sorry to hear that'¦.I guess.> I have emptied/dismantled my old tank but am struggling to clean it. The main concern is what appears to be both green and purple (probably coralline algae) on the glass and plastic back divider - I have one of those JBJ Nanos. <Ahhh'¦.you started your marine endeavor with a  'ready-made' tank and a nano at that'¦..that is why you became frustrated with the hobby I surmise.> I have tried scrubbing at it using one of those algae removal pads, but that was unsuccessful. I am reluctant to use a razor because of scratching - particularly against the plastic. <I understand.> Do you have any suggested methods given that the tank is empty. <The tank is free of livestock and empty correct? If so do the following: Fill the tank with tap water and generous portion of distilled vinegar, let it sit for at least 24 hours, then attempt to use a credit card or straight edge (Kent pro-scrapers are great) to get it off.> The tank is stored in a dark place - would it be fair to say that the algae will die off ? <It is dead I surmise, just the calcified remains left over.> With regards to my next project, I would like to create a fresh water tank which is a microcosm of a particular environment - such as the Amazon or whatever may be suitable to my tank dimensions. So I would want it to contain the same livestock, landscape, parameters that you might find in such a setting. I was just wanting to know whether you have any resources that may describe those environments and their configurations so that I could plan. <Read through the WWM and net re: the bio-tope first then if you get any specific questions I would love to help.> Your response is appreciated. <Quite welcome.> Regards Simon <Adam J.>

Coralline Algae and Hermits a-chomping    5/2/06 Hi Crew and thanks for helping all of us! <Hello back at you!  Jodie here once again on this fine and stormy evening.> We have a 30 gallon tank with 30 pounds of live sand and about 40 pounds of live rock. We have 4 very small fish and around 30 hermit crabs. <What kind?> In spite of all of our efforts, we can't get the rocks to "purple" with coralline algae. A year and a half ago, we added a 120 watt lamp. The rocks look darker now, but not purple. My wife has noticed at the local fish shop that the tanks that have nice purple rocks have no hermit crabs. She's convinced our crabs are eating the coralline algae. <She could be right...> I insist otherwise. <...but so could you.> Which one of us is correct so we can settle our wager? <Hermit crabs, especially red-legged ones, could be eating the coralline if they are lacking in food.  I would check your parameters first though, before blaming them.  Low magnesium levels can hinder coralline growth, as can nuisance algae, poor water circulation, urchins, etc.) Thanks for all of your great advise! <Sorry I couldn't definitively settle your bet.  Too many variables for me to make a solid judgment.  Cheerio,  Jodie> Charlie

Coralline and limpets (not biscuit) - 8/7/03 Bob: Well after trying to figure out what I can't grow coralline algae in my tank, I think I have finally identified a suspect. <Oh?>  I have a few of those odd little creatures known as limpets and according to an article by someone named "Steneck" http://academics.smcvt.edu/dfacey/AquaticBiology/Coastal%20Pages/Limpets.html These things only eat coralline!! <Not necessarily true. I have a "shield" limpet and he, so far, seems to definitely favor algae. I have coralline growing without issue. Not say that some will and do eat coralline, I am just defending these interesting creatures with a purpose.> It really makes sense now because I could see little patches of coralline one day, only to wake up the next morning to find them vanished! <Hmmm. What type of limpet? Do you have an ID yet?> All water parameters, Ca, dKH, etc. are all perfect - no phos, no nitrates, etc. <Excellent!> I guess I'll continue to let them battle it out (I refuse to attempt to remove one of the limpets for fear of damaging him) and see who wins - right now, it's no contest! <I really admire this decision. Coralline will grow if your parameters are as you say- So you can enjoy these very interesting creatures for what they are and grow coralline at a later time. A great attitude! A tip of the bottle to ya's for being a Conscientious Marine Aquarist! -Paul>

Lime Green Coralline - 9/10/03 Is there a type of Lime green Coralline Algae? <Absolutely.>  I have something growing on my rock that appears to be somewhat translucent lime green, hard like Coralline Algae, but it usually grows in darker corners and doesn't seem to be looking for light. <Could be a sponge, but more likely a coralline of some sort. There is a lime green coralline algae. Found on live rock from various places. I can't give you a specific name off the top of my head at the moment. Here is something I found from a chat with Albert Thiel "Green coralline is probably some form of coralline overgrown by a form of diatom whose growth is promoted by the presence of silicates. There are very few green coralline algae although I have run across several species. Most hobbyists do not see them in their aquariums though, or rarely is maybe a better way of putting it."> Will this take over my tank? <If you're lucky, but likely will wax and wane with lighting regime, water changes, and water parameters>   Should I be concerned? <Not at all! Be thankful!> Thanks for your help. You guys have a great web site and have been a great help. <your inquiries help for the betterment of all. Our webpage is a collaboration. So.... thank you. -Paul>

Coralline Algae and Acrylic Aquariums 1/14/03 Hi Bob or Crewmate, <Hi Joseph. Adam here tonight.> I haven't even received my custom acrylic tank and I'm already fretting over scratches.  Bob, in his book The Conscientious Aquarist recommended acrylic tanks over glass.  I just started reading The Reef Aquarium and Delbeek and Sprung suggest that acrylic tanks are more suitable for fish only because cleaning the coralline algae off the walls will scratch the acrylic due to the calcium. <A question for the ages!  Some folks swear by acrylic, some swear at it!  Acrylic is a better insulator, is clearer, is lighter and is more shatter resistant, but scratching can be an issue.> Just how much of a problem are scratches with an acrylic tank?  If I am careful and use the proper tools to clean the tank, will I be able to enjoy watching a marine environment in my home for many years without seeing obvious scratches on the acrylic panes?  Even though I am willing to invest substantial time, energy and money in setting up and maintaining a reef aquarium, I am not willing to do this if, after a few years, I am seeing a scratched viewing panel first and a reef second.  I would just as soon fill the 145 gallon tank up with freshwater and goldfish.  Thank You,  Joseph Rouse <There are a few tips for keeping acrylic tanks scratch free.  First, clean it often to prevent heavy build up of coralline (a cleaning magnet is a great aid here).  Second, be very careful to use acrylic safe tools and don't trap any sand or grit in the tool.  Lastly, just be generally careful in how you work in the tank, place rock, etc.  There is no doubt you will get some scratches, but under water they are nearly invisible and shouldn't detract much from your viewing pleasure.  Best of luck!  Adam>

Coralline algae growth and cleaner shrimp breeding- 2/4/04 Hey guys, was wondering if the steps to coralline algae growth is as follows: rock turns a slight green w/ "web patterns", then spots of pink, and then purple......the purple stage seems to have the same "webbing", but comes off later, looks like it sloughs off which reveals a darker purple underneath....this happens in the course of a month......calcium is 420ppm....just wondering. <Well, not having watched the stage carefully, I would have to say that at a glance this was the stages my live rock went through. Not too sure though> 2nd query of the day is: has anyone successfully raised cleaner shrimp? <We have at the Monterey Aquarium> Lysmata amboinensis.....my two shrimp in my 55 are always gravid, which they release the larvae in succession. <Correct> I managed to sieve some with my net the last time, <Beaker them out to prevent damage to the larvae> but they only lasted 3 weeks in a 5 gallon refugium that I setup for them. <Sorry to hear> I fed them marine phyto, but to no avail....any recommendations? <We have had success with Selcon and quality phytoplankton enriched brine nauplii. The have a long larval period of about 1 1/2-2 months long before they look like miniature versions of the adults> They're gravid again.....they seem to be after they molt (every three to four weeks) <Sounds about right>............otherwise the larvae will be fish fodder :( <Good luck. Great question! ~Paul>

Lucky sum ma ma or too much coralline? - 7/21/03 Hello "CREW" or whomever happens to be in today;-) <It's me Paul. Sorry for the delay> I have a problem with way too much coralline algae growth in my 125 gal reef. <Lucky bon of a sitch!> Unlike others who are trying to get it to grow it's in overabundance in my tank, so much so that it's hard to see all of the beautiful things I've paid good money to look at! <You realize everyone will have stopped reading this response by now due to their jealousy....=}> It's frustrating because I clean it off... and it comes back 10 fold!  I have urchins.. they don't seem to do anything... I don't even notice any of it gone on the rocks that they feed on it grows back so quickly.  I'm wondering if you have any other suggestions for removing it?  It's been an ongoing battle, and some say you can never have too much coralline but I tend to disagree when it obstructs the views of my fish and inverts! <Well, I use an old credit card or student ID card to scrape the walls clean. If it is glass you could razor it...... carefully.>  I don't even add supplements... I stopped in hopes that the coralline would stop reproducing, but it's been 6 months and it's still growing like it always has. <Give us the recipe. What is your PH, Calcium level, Alkalinity levels, type of lighting, how long is your lighting on, How old are your lights, salt type, water change method, anything else you think might be pertinent. What kind of urchins are we talking about. I hear Pencil and Pincushion are pretty good at chowing coralline. There aren't any real snails or crabs that can help, that I know of. Do you add anything with strontium in it?>  Please help soon, I'm starting to have nightmares about being completely encrusted in coralline!!!!!!(well, not literally, but it is driving me crazy!;-) <Again, this is a hard one, as I am under the impression one can never have too much coralline algae. I would scrape what you can off the viewing areas, leave the back glass (acrylic) alone. Fight the battles you can win and leave the rest.... Sorry to be of so little help. Let me know if you find something that works so as I can spread the word.....Bwahahahaha! Seriously, scrape it and leave it for the urchins to eat. Soak any mechanical parts (power head parts etc...) in vinegar and rinse well before placing back in the aquarium. Good luck, and thanks for letting me poke a little fun. Take care -Paulo>

Could Coralline Be Harmful? (3/13/04)   This is something I've wondered for years, but have never seen discussed. If the bacteria in live rock need to be refreshed with water/nutrients at all times in order to do their thing, what possible benefit could there be to having the LR. covered by coralline algae?   Seems to me it would serve to "suffocate" the bacteria and reduce their prevalence in the rock. (Of course, coralline algae itself does remove some nutrients from the water, so I guess it could be viewed as poor man's live rock.) <Having seem coralline from behind on my glass, I can assure you that it is rather porous. It is clearly not some sort of impenetrable barrier like glass.>   Can water actually travel directly through coralline algae's body cells? <No need. Plenty certainly passes around the cells.> Perhaps the bacteria eat the underside of the C.A. if needed, in a parasitic/symbiotic relationship. <Am not aware of such a relationship.>   In other words... If a tank has 100 pounds of live rock, with about 40% of the LR.'s surface area covered by C.A., is that equivalent to only having 60 pounds of live rock?   I suppose this number depends on just how porous one's live rock is; i.e. whether or not water can fully travel through the rock from the non algae-encrusted side(s). <Again, not a solid, impermeable encrustation. Look at it with a high-powered magnifier.>   C.A. obviously also removes calcium from the water, hurting stony corals.  <I'm quite certain the stonies extract calcium at a much higher rate that the coralline does. That's keepers of stonies measure calcium and supplement as needed.>  I don't mean to give any reefkeepers heart attacks with these questions, but I really think C.A. might be an example of something that is too good to be true, and its effects ought to be studied very closely. <I'd say there's sufficient practical experience to suggest that there is no harm. Research would be nice, but there's almost certainly no funding available for such a project.>   Chris R., New Orleans <Interesting questions Chris, but I wouldn't worry much about this. Steve Allen.>

How do I slow down coralline algae growth? 4/14/04 Hi there, I have a well established 75 gallon reef aquarium (going on 9 years now).  I never seem to win when it comes to algae.   I battled diatom problems for years, but now coralline algae is haunting me.   It grows on the acrylic so fast that it is becoming quite the pain to keep off.  I've already given up one side of the acrylic to the coralline, plus the bottom 3 inches.   Is there any way to slow down the coralline algae growth?  Is there a better way to remove it than Kent Pro-Scrapers?  Today I became so frustrated I used a putty knife to try to get the stuff off!  Help!   <Wow!  As I am sure you know, corallines thrive in high calcium, high alkalinity conditions.  Unfortunately, the conditions that favor coralline algaes also favor coral heath.  Limiting Calcium and/or alkalinity in order to limit corallines would certainly not be in the best interest of your corals.> I know some people work very hard to grow this, so here's some system info: 75 gallon acrylic Highly oversized wet/dry 1100 GPH submersible pump Sea Swirl oscillating return Venturi protein skimmer Knop C calcium reactor 2 96 watt power compacts 12hrs/day 2 175 watt 10K metal halides 9hrs/day Hang-on refugium with a power compact running the same time as the main lights 1/4 HP chiller set at 77 degrees F w/Medusa controller I do a 25 gallon water change about every 3-4 months using Kent salt.  I add Kent strontium/molybdenum and iodine sporadically, and Kent Coral Vite and Essential Elements even less frequently.  I don't test anything besides the specific gravity when doing a water change.   Any advice would be greatly appreciated.  Thank you, Mark <Other than staying ahead of it, I am afraid that I don't have any good advice.  Some urchins are good coralline grazers, but they are going to graze where they want to, not where you want them to.  Also, they tend to be quite destructive and in the long run, the little bits of coralline they liberate in their grazing activity will fuel more growth elsewhere in the tank.  Best Regards.  Adam>

OTC algae attack packs How's it going over there? <Hi Sean, MacL here.> I was wondering if the algae attack packs which they sell (which include scarlet reef crabs, turbo snails, and dwarf red tip hermit crabs), would eat the beautiful coralline algae found on live rock. Do you think it is worth adding algae attack packs to aquariums with live rock? <I can only tell you that from my experience they will eat coralline algae.> Sean F.

Bubble algae v Coralline Hi all, I have noticed that some of my bubble algae (I kind of just let it ride, doesn't seem to hurt anything) has coralline growing on it. Will the coralline eventually kill the bubble algae? If so the seems like a pretty easy way to control it. Anyone that has had this battle happen please let me know who wins. <Hmm, interesting question.  I don't think either really 'wins'.  The coralline doesn't seem to hurt the bubble algae, and vice versa.  The bubble can usually still get large and reproduce even with coralline on it.  I have had tanks with this type of situation and, left unchecked, the bubble algae will spread rampantly.> Thanks, -Ryan  

Coralline Eating Snails Hello saltwater fellows. I've searched many forums including this one for a way to rid my reef tank of thousands of pest saltwater snails. I've read countless articles on how beneficial snails can be to a saltwater tank and I have several of the good kind in all 4 of my tanks. However, I have infected my main reef tank with a saltwater snail that eats coralline algae, yes eats coralline, not dead coralline but healthy vibrant coralline algae. My tank is several years old, is well established and has virtually zero bad algae, at one point all my rocks, back and sidewalls, feather duster tubes were completely covered with coralline algae. Heck all of my snail and hermit crab shells were covered in the stuff, I had to chip the coralline out of the pump heads. About 3 weeks ago we added some fully cured rock to the tank for some additional aquascaping. The rock had the pest snails seeded in it. By the time I noticed something was wrong I had thousands (yes thousands) of them. The come out after the lights go off and cover the rock and walls of the tank. Most of the ones I net out of the tank are 1/32 to 1/8 of an inch in diameter. For the past 2 weeks I've spent hours every night pulling out pieces of rock and picking them, and netting as many as possible off the sides of the tank. They only populate the surfaces that have coralline growth on them. They've stripped half of my tank barren of coralline algae, as well as completely removing it from the shells and tubes of my snails and feather dusters. Is there anything on the market that will kill snails without harming corals or fish? After two weeks of spending 2-4 hours a night hunting these snails, only to see them come back stronger each night I'm at my wits end. My six-line is about ready to burst from the amount of snail eggs he must be finding. After believing for so many years that no snails eat coralline it's amazing to find one that multiplies so fast and seems to only eat coralline algae. Even if you don't believe that a snail eats coralline algae please let me know of any produces you've come across that kill snails. Sincerely, Sam >>>Hi Sam, Very strange indeed, I've never encountered such a snail. I CAN tell you that there is nothing you can add to your water to poison them while not killing everything else in the tank. There are wrasses that enjoy eating snails of this size, but they are the larger variety (hogfishes and such) and may not be compatible with your tank. If you don't have any small shrimp, I'd consider this option. Sorry I can't be of more help. Good luck Jim<<<

Trouble with Tribbles Anthony, First let me start by reporting the best reef conditions I have ever had. Thanks to you and yours, water is better, skimmer is functioning properly, rock and inverts are thriving, and the reef is reefier! (Did I just coin a word?) <sounds delicious!> You guys ought to wear capes!  <I used to wear one... but apparently it is unlawful to do so without wearing any other garment of clothing while standing in a park fountain> Yes, reefier. Has a nice ring to it. I'll be using that one again.) <just ducky! <winky>> I was scraping algae off the glass this morning for the first time in a couple of weeks, (snails are apparently getting lazy) and I noticed what looked like very tiny white bugs scampering around in the algae. Then I noticed that there were none left on any place I had scraped, and only collecting on spots I had missed. Upon closer examination, I could almost make out a tadpole (sperm) shape, they were white and definitely moving of there own free will.  <perhaps you've discovered the secret ingredient in some of the vital/snake oil reef supplements?> I stopped scraping to avoid possibly wiping out a colony of something cool. Any idea what they might be? <well... many desirable microorganisms...amphipods, copepods and the like. Do look up some of Shimek's or Moe's drawings/photos of such critters. Very desirable though I'm sure> Also, a couple of weeks ago, against my better judgment, I bought a really cool long spined urchin. I took the advice of a reef store that said........"Sure he'll eat your precious coralline algae, but upon doing so, they expel the spores thus repopulating/propagating the species." Is this BS?  <Hahahahahahhhahhahhahhahhahahhhahhah...........> <Ha... ha....he....hehe...he....hahahahahahahhahhahhahahhahhaahah> <woooo...hooooo...ha...hooo. Ahe...heheh. Ahem....> <Pat,...I do not believe that explanation by your LFS was entirely correct <tear>> I have noticed a whole lot of chewing going on. Can this little monster actually chew down my reef? or is the new coralline growth I'm starting to see (on the snails of all places) evidence of this. I hand picked all 75lbs ( and counting) of my rock for it's abundant coralline/calcareous growth and I'd hate to see it all devoured by this aquatic tribbles, as cool as he is. <in fact, I agree that the long-spine urchin is pretty cool. Yes they can eat some coralline algae...but  no, they do not shoot "Magic" coralline algae spores out of their bungholes....hahahahahahahah...heheheheh, wooohooooo. Oh, yeah! I got to get the name of that sales clerk and thank him for that one <smile>! Anyway... my take on the urchin/live rock deal is that I would recommend them for tanks that for whatever reason grow enough microalgae for them to graze. In such cases their presence serves the greater good. Else, they eat more coralline algae than most people can grow. If you see that exposed white carbonate material on the rock than pink, etc corallines sprouting...pull the urchin. Else, enjoy it>> Hey anyway, have 65 nice days in a row. If they ever come out with a small porous statue of you, I will surely sink it in the tank so as it seeds, my animals can all have someone to worship.  <I'm actually hoping they manufacture my likeness in one of those springy tassel dolls that you can mount on the dashboard of your car. But if you do submerge a statue of me in the tank, please cultivate some long hair algae on my head so that I look taller> As always, thank you. -Pat <with kind regards, Anthony>

Something is eating coralline Hey there oh faithful gods of the sea. <<And hey to you...> my coralline is being eaten by someone. <<oh?>> I have the standard cleanup crew, including a giant emerald crab along with 2 smaller ones. hermit crab, etc. I noticed the blue claw hermits spend a lot of time picking at my rock. shrimps also. could it be them? <<I doubt it - what are you doing to supplement calcium in the tank? Coralline is a calcium-based algae and needs a steady supply to flourish.>> no loss of coralline in areas next to the wall of my tank, where nobody fat could fit, 1/4 inch clearance. should I catch the beasts and put them into one of my other, less pretty tanks. which could it be.?? <<I didn't see mention of an urchin of any type, and I've never seen a crab or shrimp of any type eat coralline algae. You might want to check out this URL and the FAQs beyond: http://www.wetwebmedia.com/corallinealg.htm  >> thank you, Renee RN <<You are quite welcome. Cheers, J -- >>
Re: Something is Eating Coralline
By far, the most awesome gods, you are right! I have a pincushion and a pencil urchin. That's what is eating the coralline. poor giant emerald crab, I caught him and threw him into another tank. I guess I could put him back now...urchins...ugh. <<while I appreciate the kind words, I can assure you, I am quite human and make many more mistakes than any god should. But where were we?? Urchins... yes... they are like self-propelled Brillo-pads.>> yes, I supplement calcium and drip Kalk at night and etc, etc. little coralline dots growing everywhere else. <<Ahh good, well we've now solved the mystery of the missing coralline so no worries about the calcium.>> which urchin to remove or both? <<Well, depends just how much of the coralline they are removing - if you can live with a little loss - recall this is food for them - then keep them. I'm sure you can find balance there somewhere.>> can I put him/them into a tank with a giant carpet and two clowns? <<sure.>> another subject...cuz gods can do more than one thing at a time. <<well, actually, I'm done with that previous thing so... sorry to disappoint, but... one thing at a time here ;-) >> how do the fish retain color. I buy clowns from ORA and they are BRILLIANT. then they gradually turn regular color. what do they feed them. <<A better question to ask would be, what do you feed them?>> I am truly blessed to have such bright and attentive gods to watch over me.\Renee RN <<Cheers, J -- >>

Cleaning Acrylic Tank I am looking for a way to remove coralline algae from the front of an acrylic aquarium. Anything will help please! -Donovan <I like to use the scrapers from Kent Marine. I believe their red plastic blades are acrylic safe. -Steven Pro>

Coralline algae on glass Hello! How are you today? <Extraordinarily tired. I had to go work on my in-laws farm picking pumpkins.> I have been adding some strontium to my tank, according to the directions on the bottle. After a few weeks, I am starting to get coralline algae growing on the glass of my tank. It is a pretty pink and purple color. Is this normal, or is it too much coralline growth? <I would never say you could have too much coralline.> I have since stopped adding the strontium to my tank, (it is a 29 gallon with 25 lbs live rock). I think that I am getting enough strontium by just doing water changes, from the salt mix. <If frequent enough, large enough, and demand low enough, possible.> The coralline on the glass is slow growing. Should I scrape it off or let it go? <I let it go on the back.> It is harder to scrape off than nuisance algae! <And far better for your tank.> Thanks again, Kevin <You are welcome. -Steven Pro>

Purple Algae Growth My question is that I cannot get my purple coralline algae to grow. I dose with Kalkwasser and use high output lighting (Metal Halide and 2 VHO lamps).  I use Reef Crystals and do water changes every two weeks. Any suggestions on how to boost up the purple algae or any other products that I could be  using?? Thanks. >> Hmm, well you need at least to look into alkalinity (takes both this and calcium to grow corallines), and the possibility that you have Hermit crab species that are eating your corallines faster than they can spread... Or that you have other life that is out-competing your corallines for alkaline earth minerals, and other nutrients (like some fast growing macro-algae)... Any of this "ring a bell"? Bob Fenner

Help Bob: Tonight my wife noticed something awful. My coralline algae is getting covered with green algae. I've written before, so you know the tank conditions. What should I do -- Get rid of my wife, or is there some way to reverse the situation? <A few things can be done... either changing the chemical and physical conditions to favor the encrusting reds/disfavor the greens (like elevating pH, insolubilizing phosphate by administering... Kalkwasser to a pH of about 8.4-8.5...), or adding some (more) green algae eaters (Mithrax Crabs, Salarias Blenny (one), Blue Legged Hermit Crabs...), placing organisms that will produce chemical antagonists (the usual plug here for macro-algae in your main tank, or a sump... ideally as a lighted mud/muck filter arrangement... Or just allowing "succession".... Keep the wife> I stopped Kalkwasser and started adding 5 ml of calcium each day along with tech A&B (plus usual chemicals each week). <Ahh, see above> By the way, it was 80 degrees here in Indy today!!!! Being a southern boy, I love spring when it's supposed to be here (not May, as usual for the Midwest). <Yeah, this last week visiting with friends in PA in the fish business and hobby, it was nicer there than back home in San Diego... Bob Fenner>

Coralline Algae Quick question for you Bob. Coralline algae. It's starting to "prosper" quite well in my tank. I have over 100 pea sized growths on my tank. These are all green. I'm going to let it encrust the entire back and sides, and the lower 1" of the front... does this sound okay? <Sure> I do see about 10 of the pink variety starting to grow as well. Is there a reason why the green grows so rapidly while the pink took over a month longer to begin growing?  <Mmm, yes... conditions favor this type/species... more light, perhaps lack of available biominerals, alkalinity... perhaps predators are eating the encrusting reds... a few other possibilities> I'm wondering if different color coralline grows better under a certain "color" of light. <Yes... not so much apparent color but wave lengths, intensities...> Not so much that I care whether it's green, pink or purple, just my curious nature pondering a question that wasn't answered by your FAQ's. - Euge <Point taken. Be chatting my friend. Bob Fenner>

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