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FAQs about Red Calcareous and Coralline Algae Identification

Related Articles: Coralline Marine Algae, Red Algae in General, Avoiding 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 1, Coralline Algae 2, Coralline Algae 3, Coralline Algae 4, 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 Aquariums, Marine 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,

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Marine Aquarium Algae Control

by Robert (Bob) Fenner

Coralline Algae, Cyano, or ???     8/3/19
Hi Bob -
I am stumped trying to figure out exactly what's growing on my glass and rocks in my 265 gallon FOWLR tank. I've attached a few pictures. It doesn't come off very easily at all. Frankly, to get it off the glass you have to use a scraper with some force, then to get it off the rocks, good luck as a tooth brush will very slightly thin it out, but if I really wanted it off, more likely it would take a steel brush with some force to get it off the rocks. Further, when I scrap it with force off the glass it comes off as a dust, not in sheets.
Thus, based upon this hard consistency my gut tells me it's Coralline Algae, yet I am used to Coralline algae being pink or light purple, not red in color. It's a dark, burgundy red, similar in color to cyanobacteria, but I definitely can't siphon it out like you can with cyanobacteria. Should I be concerned?
Thank you,
<Hey John. Coralline (encrusting Reds, Rhodophytes) are very different to the touch than Blue Green "algae"/Cyano... The latter are slimy; and of many different colors. Reds are not slimy, but hard, crusty... From your description and photos this appears to be BGA...
Yes to being concerned... conditions that allow, encourage BGA are deleterious to most all other life forms as are some of the metabolites of Cyanobacteria.
Please read here re the several approaches to control: http://www.wetwebmedia.com/bluegralgae.htm
and the linked BGA Control FAQs above. Bob Fenner>

Re: Coralline Algae, Cyano, or ???     8/4/19
Ugh. Terrific article. Thanks Bob!
<Cheers John! BGA is defeat-able, avoidable... Like steering a large ship w/ a small rudder; takes a while, but... slow and steady is the route to go. BobF>

Coralline issue; ID from pix?    12/13/17
<19 megs of pix? Did you read our requirements?>
Posted over on r2r and they suggested to email you guys and see if you know what kind of coralline algae this is.
<... Kind? As in species? Not w/o microscope imagery>

Grow supper fast. Grows in to shaded to dark places and is slimy when removed from the tank or rubbed on in
tank. The one shell pic has been out of water now 9 months been rinsed a few times in tap water. Here is the post over on R2R about it and what I have went threw in my tank.
Thank you if you respond and thank you if you don't would understand.
<See, as in READ on WWM re Corallines? Bob Fenner>

Hair turning red 4/30/11
I have visited your site many times and always found the answers to my questions amongst the pages. It's been really helpful as I've only had my tank 6 months and everyday seems to bring a new question! Anyway, I searched for an answer to my latest query but could find none so I am writing to you today.
My 24g marine aquarium is going fine and water parameters have been stable and good for some time now. Ammonia, nitrite are zero and nitrate and phosphate as near to zero as possible (less than 1ppm each). Ph varies between 7.9 and 8.1 depending on time of day and specific gravity is 1.023.
<I'd raise this... see WWM re spg>
I have a few different corals which seem happy but I notice that one of them is growing red.
<... Do you mean the algae here?>
By that I mean the new growth is red. When I bought this I was told by the LFS that it's maiden's hair. You can see it in the first attached picture.
Is it supposed to be red or is this some kind of Cyano growth? I would say some bits have doubled in length in 2 weeks but all the new growth is red.
A second patch has grown all by itself on a piece of rock that another coral came with. I've attached a picture of that too as it doesn't seem to be growing red at all. Is this second one also maiden's hair or is it something different?
<Just more resistant for now>
In which case is it desirable or not? It looks more fern-like to me.
<This is a Chlorophyte, a green algae, being overgrown by a type of encrusting Red Algae...>
Kind regards and thanks in advance,
<Welcome. Bob Fenner>

Re: Hair turning red 4/30/11
Hi again and thanks for the super-quick reply!
Apologies for asking too many questions in one sentence but does your answer "yes" refer to it being normal to be red or to it being a Cyano growth?
<Sorry for the lack of clarity. This green growth is an algae, not a coral, and the one patch is being overgrown by a Rhodophyte... a red algae, NOT a Cyanophyte. B>
Kind regards,

Re: Hair turning red 5/2/11
Hi once more,
After the clarification I decided to give the algae a "hair-cut" to remove the red-encrusting ends.
I did this in the presumption that the red was not desirable but with hindsight I'm not sure why I thought that. Was that a correct assumption - that the red encrusting algae is bad?
<Is not "bad" for your system... a bit of natural succession. Is bad for the "maiden hair" algae... in that it will slow down its growth somewhat...>
There seems to be a lot of conflicting opinions on the internet regarding this and I'm not sure which to believe.
<Then do nothing till you understand>
Anyway, whilst attempting a hair-cut a crab scuttled out from underneath.
It's about 2.5cm across and seems to have lost a claw. The nearest thing I can find on your ID pages is Lissocarcinus laevis
but I cannot find information about whether or not he is desirable in a reef tank with fish and other invertebrates. I have attached a photo.
<Most Decapods are not... if this one isn't doing any apparent damage, I'd leave it be; enjoy it>
Kind regards,
>And you, B<

Coralline algae Identification requested. 12/7/10
Hello Wet Web Media!
<S of C>
The WWM site is overwhelming, it takes ages for me to search any given topic. SO much information here that I can never know where to start; but it makes for good reading all the same.
<Mmm, the topic/s of ornamental aquatics are so vast themselves... we do have a search tool onboard to allow the viewing of cached terms... And the indices are as logical, descriptive as I can (ongoing) make them...>
I have spent many nights sifting through bits and pieces. Anyway, I've done what I could to search the site, and the web for information. Failing that, I thought I would once more ask for some help identifying something that has caught my attention. Last time it was my mini carpet anemones <3
What I have is, I think, Coralline algae. This is not unusual, I have all manner of it growing everywhere. It's something that enjoys my 10 gallon tank and grows with alacrity. What is unusual, at least to me, is that a small area of the coralline has grown with "yellow highlights" It seems to be entirely different from what else is in my tank. Red, purple, Pink, Green... Please tell me, what is this beautiful specimen?
<... Don't have "that" much confidence in my guess here... is the underlying bit hard, stiff to the touch? This looks like some sort of blue green (the red stuff) overgrowing... perhaps Lobophora to me. Reach in and give it a twist... is the underlying bit flexible? The outer, reddish material slimy?>
My latest change to my system was a new bank of lights and some frags. The tank did have about three months of "neglect" due to some unfortunate events. The coralline and corals did not suffer, most of it continued to flourish-not the mushrooms though.
This is so very pretty
I have included a picture of the algae in question as clear as I can get it. the area it covers is about two inches high and about ¾ inch wide at most. I would like to encourage it's growth as I love algaes.
Thank you so much for any help you can give and for helping me out in the past.
<Welcome! Bob Fenner>

Re: Coralline algae Identification requested. -- 12/08/10
Reply: regarding my "Coralline" algae Identification request
Thank you so much for your prompt reply
<... Don't have "that" much confidence in my guess here... is the underlying bit hard, stiff to the touch? This looks like some sort of blue green (the red stuff) overgrowing... perhaps Lobophora to me. Reach in
and give it a twist... is the underlying bit flexible? The outer, reddish material slimy?>
I have to admit, doing the test you request is a bit difficult as these are very small, but I did Google Lobophora and brought up a very very similar looking algae with the beautiful red and yellow highlights. When I did attempt to test it, yes it seemed to be somewhat flexible and a bit slithery to my touch.
<Ahh! Then at least NOT a coralline>>
Thanks so much.
<<Welcome S and or S/S. B>>

Red Stuff On My Rock, Nullipora 11/23/09
<Hi Paul>
I have had this problem with my tank for about a year or so and this time I cant seem to solve it.
The tank is a 175G Oceanic bow ,and has various creatures within it and they are no problem.
My issue is a red hard coating on all my live rock I have tried to mechanically remove it and it won't come off. I think it piggy backed on a batch of live rock I bought and it spread and stayed. Its not coralline algae, I have that still in spots, but its the same consistency. Its not slime algae I have had that before and used slime remover and it left, this is different and even though I have taken a piece of live rock out and tried to scrub it off it will not come off easily.
I have seen this red stuff being referenced on the net and its been said that there is nothing that will take it out. I used an urchin and it eats it but unfortunately it also eats coralline algae and can't get in tight spots.
I guess my question if you guys have the time would be, have you heard of something like it and a way of removing it short of scrubbing my rock clean? I have had this tank for 5 years.
I understand that I probably have omitted a lot of info but I am trying to keep this letter short in the hopes someone has heard of this stuff before, and an explanation of all the other stuff I have in the tank would not take up time which I have a feeling you guys don't have a lot of.
<The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white or gray-green.
You likely have a red variety of coralline algae. The urchin eating it is a good indication of this.>
Thank you in advance.....
<You're welcome. James (Salty Dog)>
Paul Carragozela

Brown Coralline? 11/09/08 I've had a dark brown slightly reddish coralline algae starting to spread on my back overflows, Koralia's and some live rock. It looks just like the coralline type but the color is wrong. I cannot seem to find anything about this type of algae on the forum. Any ideas? <It could just be the red coralline instead of the purple you are used to seeing. I'm supposing it looks brown because of your lighting. If it is hard and crusty like the purple then no worries. If it is filmy and slimy then it could be cyano or diatoms. But most likely its just a different color coralline.> Thank you for all the support! <Regards, Jessy>

Algae I.D. 09/27/2008 Greetings Crew, <<Good morning, Andrew today>> Thanks for the great site! I have looked high and low for information on this algae but I can not find it anywhere. Forgive me if I've simply overlooked it. Thanks in advance. <<Corallina elongata i would suggest. Please do use your search engine for plenty of info on this algae>> John T. <<Thanks for the questions, hope this helps. A Nixon>>


Re: Algae I.D. 11/02/08 Hello again Crew, <Hello, I'm so, so sorry this email does not appear to have been answered after all this time.> I've looked up Corallina elongata but I am unsure that is what I have. I did find this page www.wetwebmedia.com/trialalgaeid.htm <Ah, I'm glad you found that page.> with a similar looking algae. (Very bottom row, in the middle) It's listed as possibly being Fauchea. I'll keep up the search. <Macro algaes are indeed often very difficult to ID by eye, by picture.> Is it not ironic that our passion teaches us patience but when we have questions we want answers right now? <Hehe... "the more we know, the more we don't know."> Thanks again for a great web site and for taking time to help. I live in an area without a LFS and as far as I know have the only salt water tank in town. I could not have done it without Wet Web! <Great to hear, thank you for the kind words!> John T <Best, Sara M.>

Coralline or not? 5/23/08 Hi WWM Crew, <Hello> Sorry to pester, but I've been trying to determine if what is growing on my rock is/is not the much-sought-after coralline algae or not (see attached photo). <Looks like it to me.> I had a bit of a "red slime" problem on my back glass that two Trochus snails resolved, but even when they come to this rock, they have been unable to "clean" it, nor have my burgundy hermits. I just stuck my hand in and scratched it a bit with a fingernail, and it didn't "ooze" off like the red slime did when I touched it. <Sounds like coralline to me.> The rock in question is the white(ish) one in the center. I picked it up from Hanauma Bay seven years ago after it washed onto the beach. When I placed it in the tank a month ago, it was totally white, but this stuff has turned it progressively darker. I am not getting any kind of the same growth on my glass or any other rock, so I'm a bit confused as to why it would limit itself to this rock only. <Something is favoring it's growth in this spot, lighting, water flow most likely reasons.> An added bonus would be if you might be able to give me an idea what this rock is. <Looks like fairly standard reef rock.> Thanks, as always, for your timely and sage replies! -DS-
Red Fuzzy Coralline? '¦Not likely, perhaps another Rhodophyta -- 08/26/07 Hello crew! <Hi Dave, Mich here.> I have been researching your site and others trying to figure out what is growing in my 90-gallon reef. <OK.> I have a red feathery/fuzzy substance growing on a lot of my rocks, snails and hermit shells. <OK.> I was wondering if it was a type of coralline and harmless in my tank. <Only guessing without a pic.> I am very familiar with cyano and I don't think this substance is it. <OK, One of many possibilities off the table.> It is very difficult to scrub off, and grows in high flow areas unlike cyano. <Still leaves a plethora of possibilities.> I read a similar query asked by another gentleman on your site. The reply to him was that it was coralline, and that he should drop some vinegar on it to see if it bubbled to be sure that it was. I tried this experiment on my substance and it did not bubble. <Then it is likely not coralline or any other calcium based organism.> The other gentleman described it very well, in my opinion, by saying it appears to look like patches of red mold. <Many nuisance algae come to mind, red turf algae or red hair algae such as Polysiphonia, Asparagopsis, Anotrichum barbatum, Gelidium pusillus, or perhaps a beneficial organism such as a red tree Foram (Homotrema rubrum) Your expertise would be greatly appreciated. <A photo might help here.> Thank you all for this amazing site! <Thank you for your kind words!> Dave Kansas City, MO. <Mich Gouldsboro, PA.>

Re: Red Fuzzy Coralline? '¦Not likely, perhaps another Rhodophyta... BGA 8/28/07 Mich, <Hi there Dave.> Thank you, for your quick and very helpful response! <Welcome!> I have been researching your suggested algae species and I am continuing to have problems identifying which is growing in my tank. <Yes, does not look like what I was picturing in my head with out the photos.> I hope that they attached picture of the red substance growing on my glass magnet might help you take a better guess at what it is. <Mmm, pics are helpful. Is not a red tree Foram and likely not many of the algae I suggested previously, is a nuisance alga, likely a Rhodophyte, but beyond that I can't tell. Perhaps RMF will comment on the dailies page.> <<Is highly likely Cyanobacteria... a quick look under a few hundred power microscope would show the absence of nuclei, organelles, the distinctive circular DNA if higher powered... Please read on WWM re BGA... RMF>> This is the way it appears everywhere in my tank, (rock, hermit shells, powerheads) short, red, and fuzzy. <No fun. Perhaps some improvements in husbandry would help? http://www.wetwebmedia.com/nutrientcontrol.htm http://www.wetwebmedia.com/marine/maintenance/marineMaint.htm http://www.wetwebmedia.com/avoidingalgaeproblesm.htm > Thank you for your time, <Welcome, wish I could be more helpful. Mich> Dave Mmm, think I forgot to move an image into the emails with images folder... re: fw: re: Red Fuzzy Coralline? atten: Mich <No worries... was there somewhere. Found, posted> Also He stated earlier: It is very difficult to scrub off, and grows in high flow areas unlike cyano. <Is almost assuredly BGA... B>

Re: Red Fuzzy Coralline? '¦Not Likely, Perhaps Another Rhodophyta... Nah, Cyanobacteria -- 08/31/07 Mich, <Hi Dave.> Thank you again, for the quick and helpful reply. <You're welcome!> I was however disappointed that I could have some yucky cyano in my tank. <It happens to all of us. Glad you can't see my tank right now!> Let me give you a little background on my tank and husbandry. It's a 90-gallon reef with a medium bio-load. There is no detectable nitrites, nitrates, or ammonia. However with the phosphate test kit that I have, (which is very hard to read, maybe time for a new one.) I think I may have a slight amount of phosphate in my water, less than 5ppm (however, with the color chart its very hard to determine if its actually 0) Calcium and alkalinity are within parameters, and my ph. stays pretty steady, and high, around 8.4. I have an all-glass model 3 wet dry. <If you have a wet/dry, you most assuredly have nitrates, if your getting readings of zero it is because your algae, nuisance or macro is using it up. Yes, I do keep a close eye on my nitrates. ANS G-3 protein skimmer, which works great, and I use RO water. I religiously change 4-5 gallons of water weekly. <About twice that amount would be better.> I don't have a lot of live rock, around 75lbs, and my sand bed falls into the poor thickness range, 1 1/2 to 2 inches. <Nutrient sink and not deep enough to be very helpful with anaerobic metabolism.> So I consider myself very conscientious about my husbandry (except if it really is cyano, it has to be from me being such a sucker to my Kole tang.... he likes to eat, and I'm easy). <Heehee! Could be a contributing factor.> So when I saw that yourself and Bob both think its cyano, it really made me think about my feeding habits. <Nix the Wet/dry, deeper sandbed, add some macro, bigger or more frequent water changes...> Nevertheless, I took your advice and took a sample of it to the local high school, where my mother teaches biology and put it under a microscope. <Cool!> It took a few adjustments, but I found that this substance definitely has a cell wall and what appear to be organelles, however I could not identify a nucleus. If so, does cyano bacteria have anything that appears to be cell walls, because this substance had a definite structure? <Yes Cyanobacteria do have cell walls and although they are truly prokaryotic their internal membranes are elaborate and highly organized and may resemble organelles. The missing nucleus further suggests Cyanobacteria.> I understand its very difficult to take stabs at the millions of possibilities it could be, but your advice has been so beneficial thus far, I thought I'd put the ball back in your court. Any more guesses would AGAIN be very helpful. <As Bob suggested, is likely Cyanobacteria.> Thanks yet again, for your time and dedication to your absolutely wonderful site. <WetWebMedia is Bob's baby. I am but a minor contributor to his massive endeavor. But thank you for these kind words on behalf on Bob on the rest of the crew.><<Uh huh. RMF>> Dave
Kansas City, MO.
<Gouldsboro, PA>

Purple on My Glass 1/1/07 Hello there, <Hi> I need some info on an issue with my 29 salt. I have some light purple spots on my glass and powerhead and other things in my tank. It won't come off with the algae brush. The LFS said that it was ok, and he called it something but can't remember what he called it. It kinda of crust, it scraps off with my finger nails. Is there something that I can buy or use to get this off at least my glass? Thanks for your info. Cody <Coralline algae, many scrappers available to remove it from the glass. See http://www.wetwebmedia.com/corallinealg.htm for more.> <Chris>

Coralline Algae/Alkaline Precipitation/Ca Reactor Tuning - 12/07/06 Hi Eric, <<Hey Ken!>> I hope all is well with you. <<Indeed it is...thank you>> Things have been going well with the tank, but I have a few questions. <<Ok>> The tank is set up 6 weeks now. The few soft corals and star-polyps look good. <<Excellent>> I did buy a clean-up crew about 10 days ago. I feel like I should put the snails on the payroll. In the first two days they cleaned all of the greenish algae I had on the rocks. <<Cool!>> The tank looks good. My nitrate is less than 1-ppm and phosphate is zero using LaMotte Colorimeter. <<Very good>> The pH is usually 8.10 to 8.20 and ORP has been about 415MV. <<More good news>> I also have gotten more and more pink coralline algae on some of the rocks. My first question has to do with that in the last couple of days I am getting areas of a burgundy color on the rocks. <<Coralline algae comes in "many" colors>> It looks to be more on the areas that have some of the pinkish coralline. <<Conditions in those locations are likely "optimum" for both species...everything competes for space on the reef>> Also I notice the burgundy color is all of a sudden on a lot of the turbo snails. <<Very common>> Is this just another color coralline? <<Indeed it is>> I am hoping that it is not like red Cyano or something. <<Can usually tell the difference>> I don't see this on most of the rocks and none on sand, powerheads, sand etc. I tried scraping it off with my fingernail and it does come off somewhat. It doesn't seem as hard as the pink coralline algae. <<Differences in structure/composition>> I'm not sure if this is coralline or not. <<Likely so>> I would say that I see this burgundy color mostly on places that had pink to begin with pretty much. My next question has to do with my AGA Mega Flow. Their isn't really any algae on my rocks or tank, but I do have some thick greenish layers of it in the overflow box only. Should I leave it their, or manually remove it, or can I put a couple of my turbo snails in there to eat it. <<Can remove or leave, whichever you prefer...I would not put turbo snails in the overflow box (will probably get there sooner or later anyway, but...) as they will get in to the overflow pipes and restrict/block flow>> I thought about snails and overflows but the Durso pipe and the return pipe are sealed unit and nothing could get in there. What do you think? <<If you have some kind of "screen" on the Durso then this may be fine>> By the way, if I manually remove the algae will anything? <<...?>> I don't want to spread it around the tank? Also is it possible that this algae is in its own "container" and it can act like a refugium in a way? <<Sure...on a very small scale. If nothing else, it is removing nutrients...but I'll bet close observation will reveal some tiny crustaceans living there as well>> My last question and most perplexing and bothersome to me has to do with my calcium reactor. I have an MTC Pro-Cal calcium reactor. I don't run it all of the time as my tank is only 6 weeks old and there isn't much in the tank to take up the Alk and Ca. When my alk gets down to 8dKH, I turn on the CO2 and run it at 1 bubble per second and the effluent at .02 ml as per the instructions. This is their starting point. <<And as good as any>> I will shut of the CO2 once the alk hits 10 or 11 dKH. My Ca usually is in the 410 to 425 ppm range. The strange thing is that once I run the Ca reactor for a day or so, I see some of the rock (usually more evident where the coralline algae is) start to get a whitish tone to it. It does not blow off. Also, and more importantly, when I take a turkey baster, I can blow off what almost looks like ash. <<Sounds as if you may have some carbonaceous material falling out of solution>> This has happened all three times I ran it. <<You may want to consider experimenting with different reactor media>> I was wondering if it was calcium precipitate, but how could it be? <<Easy enough...the water can only "hold" so much material. Maximizing alkalinity (11dKH) and calcium (425ppm) over saturates the water with carbonaceous material. Try test your alkalinity AND calcium after one of these events...likely BOTH have fallen as a result>> All of the parameters are in check. I am not using limewater or any additive and I do 20% water changes weekly with Reef Crystals. Do you have any ideas? <<The reactor is probably "too large" for the system (right now anyway) and is producing to much alkaline and calcium reserve than the tank can "use." I would turn to one of the two-part alkalinity/calcium supplements for now. Based on your future stocking levels/specimens, you may find you don't need the reactor>> By the way, I am using CaribSea Geo Thermal aragonite for the media. <<Mmm, I see...this product is likely soft/more soluble than others...try adjusting the reactor effluent to a pH of about 7.0 the next time you use it and see what results>> I did buy a kalk stirrer and plan on using it with my dosing pump and float switch for top off water once I have the time to set it up in a few days. <<Proceed with caution here...for now anyway>> I appreciate your help. Regards, Ken <<Always happy to assist. EricR>>

To Be Coralline or Not To Be..... 11/11/06 Hi there, <Hi> my aquarium is newly setup and cycled with live rock and I've watched many colors change and algaes and such spread, I now have a bright red patch of algae, that just will not scrub off with a tooth brush, a lot of my rock is very deep red, and I can scrub and scrub and it wont go away, what I am curious about is this patch (on the photo) is it red coralline algae, and should I worry about it? It had grown from two dime shaped patches into one of that size in about 2 weeks! My nutrient levels are all 0ppm. Any insight you could offer would be great! ~Ryan You have been sent 3 pictures. <A little hard to tell in these photos but my guess would be that it is coralline and no need to worry about it.> <Chris>
To be coralline or not to be..... 11/12/06 Hi there, my aquarium is newly setup and cycled with live rock and ive watched many colors change and algaes and such spread, I now have a bright red patch of algae, that just will not scrub off with a tooth brush, a lot of my rock is very deep red, and I can scrub and scrub and it wont go away, what I am curious about is this patch (on the photo) is it red coralline algae, and should I worry about it? <Is coralline, not to worry> It had grown from two dime shaped patches into one of that size in about 2 weeks! My nutrient levels are all 0ppm. Any insight you could offer would be great! ~Ryan You have been sent 3 pictures. <Please read here: http://wetwebmedia.com/corallinealg.htm and the linked files above. Bob Fenner>

Coralline algae 11/19/05 Dear Bob, I have a bit of a stupid question. I have live rock in my tank that has been there for approx 2-3 mos. I have a 180g FOWLR. The rock is growing pink and red encrusting algae. There are areas on the rock where there is green algae growing and I am having a hard time determining if this is coralline algae. The green algae doesn't look like it is "encrusting" but when it grows on the walls of the tank it feels like fine sandpaper. On the rock, the porosity of the rock that is covered by the green is evident. Unlike the encrusting pinks where the rock is "plated" I had a piece of dead fire coral in the tank that first grew pink, then green algae. This algae is not removed very easily and it is not slimy to touch. I have noted that it is now growing in the gravel of the tank. Is this likely to be coralline ? Jimmy <Well... encrusting is a descriptive term... usually associated with given species of red, brown and green algae... if it's hard, rough to the touch... is "encrusting"... but coralline refers to Reds/Rhodophytes of algae species... and these do look red, unless bleached (then white). Bob Fenner>

Coral / Algae Id and care WWM Crew, <Hi there> Could you please provide an identification of the material that is encrusting this rock (the "bumpy" purple and green stuff)? I first thought that this was coralline algae, but after searching your id pages and others on the web, I do not know what to think. <Looks like an encrusting Red (coralline) and some sort of green algae to me as well.> I would like to also the care for this particular material. We think that it is very attractive It came in on our LR, but as you can see on the lower left hand portion of the picture, the material is receding, and on the top of the rock, it is bleaching (turning white). On another piece of LR that did not have as much of this material on it, it is almost gone. <Please read here: http://www.wetwebmedia.com/corallinealg.htm and the linked (in blue, at top) FAQs> Setup: We are setting up a Oceanic 75 gal. mini reef tank. The equipment currently in the tank are 2 MaxiJet powerheads,4-65W PC Coralife (2-10000K and 2-actinics),Prizim Pro skimmer, Oceanic w/d sump (bio balls removed - put skimmer in the "old bio area" - the output of the skimmer goes into the refugium with has LS and red Gracilaria growing - reverse photoperiod of about 12 hrs.- which then overflows into the pump area to be returned to the main tank), Eheim power canister filter (with floss and activate carbon in it) and a UV sterilizer (not on) in a separate loop. We currently have about 60 lbs. of LR (LR is Fiji (45%) and aquacultured from FL (55%)) and 45 lbs. of LS. The sand bed (mix of sand and LS) in the main tank is 3" of fine sugar sand (a little medium fine aragonite mixed in). The tank is about 8 weeks old. <This is "very young"... and has a direct bearing on the vacillation in the encrusting algae you are experiencing... You need to maintain biomineral and alkaline reserve levels... over time... to grow all> The tank was cycled with the uncured LR and LS. For the past 4 weeks our water tests have shown ph 8.2, ammonia 0, nitrite 0, nitrate 0,and a temp. of 80-82F. Within the last two weeks we have been testing alkalinity and calcium. The current results are KH 11 dKH, GH 40+dkh (got tired of dropping reagent - is this possible or do I have a bad test kit?), and CA of 255. I know that I need to increase the CA levels. <... please have a read on WetWebMedia.com re these materials> I have been adding small amounts of Kalkwasser to increase the CA, but from reading your website, I would guess that I am close to a precipitate snowstorm. Therefore I need to do water change to lower the alkalinity so that I can raise the CA -- Do I understand this correctly? <Partly> We added the PC lights about 3 weeks ago (before only ambient lighting and 1 48" NO Coralife flour.). Over the last two weeks this material (referred to above) on the LR has been receding (mainly the dark and light purple, and dark and light green algae -- the pink coralline seems to be growing well within the last week (after we started supplementing the Ca - small spots on the glass, on the dead rock, and a little on the sand). Is the receding material due to the water quality issues (low Ca and high Alk.) and/or acclimation to the new lights? <More the former> Or is this too much lighting for this tank? Or some kind of disease? <No on both counts, your system is "settling in"... you need to settle on a regimen of testing and whatever supplementation you're going to utilize. I encourage you to look into simple two part systems (Wilken's/C-Balance, Stark's ESV...) and stop the yo-yo'ing with Kalkwasser. Bob Fenner> Thank you in advance for your assistance!

Red coralline VS Cyanobacteria Hi guys, hope you are all well. <Hi and thank you we are all well and happy.> I am in the process of upgrading my tank after a near total loss, so I let the tank sit with minimal maintenance for several weeks (which did good- the corals I have left all have come out in full). <Sometimes less is more.> I have had red-slime problems in the past, and I would siphon it out and blow it off the rocks with a turkey baster.<That is a good practice but I would use the baster first then siphon it out.> I cannot blow this red stuff off the rocks, its hard to brush off with a toothbrush (even with toothpaste-:)) it "feathers" off the rock (like tree fungi), and is nearly the same color as Cyano. Is it red coralline? <It is absolutely coralline algae. If you want to be sure take it out and put it into some vinegar. If it bubbles then your are in business.> Thanks for being there to answer oddball questions! <Not a problem! MikeB> James

- Questions: Is It Coralline? Or Is It Cyanobacteria? - Hello. I've started the hobby for about 6 months. Now I have: 2 yellow tail damsels 1 fire damsel (mean little buggah, constantly fighting with or getting picked on by one of the yellow tail) 1 clown fish 1 yellow tang 1 blue tang 1 cleaner shrimp 4 brittle stars 4 turbo snails I recently notice a bunch of white critters on my glass...the fire damsel has been picking on these for awhile since I got him. And now the pods are everywhere which I'm assuming is good? <Yes.> During the whole time I started I don't have a sump nor skimmer. my first water change was a month ago...since then I do a 5 gallon water change once a week or more depends. As of now, I notice red pinkish patches on my rocks. The patches aren't very thick... just a very light covering. I was thinking it was Cyanobacteria (something I shouldn't want?) My cousin said it might be coralline algae and the only coralline are on the tips of my turbo snails (I could be wrong) or the water I've been getting. And I don't know what I've been doing to promote coralline. <It happens [or not] on its own... in presence of adequate calcium.> I do however have a killer green algae farm growing on the right side of my tank just for my tangs just until I can put together more rocks to start on coral. If it is coralline, is it possible for one color coralline changing to another color? <Not usually. A quick note: in the future, please don't send along such large images. They clog our inbox and then block other's email from coming in. Thanks... cheers, J -- >

Coralline Algae 24 Jan 2005 Aloha WWM crew, <Aloha Richmond, MacL here with you this morning.> I was wondering if the color crust on my turbo shell is coralline? <That would be an affirmative.> If so, could any of the algae on my rock in picture 2 be coralline? <EEK I didn't see picture two, just picture one but I'm guessing that it could be. Coralline is very hard to the touch an actually hard to remove.> How can I go about in promoting coralline growth and detour the others from competing with it? <Coralline generally shows up on something, on the sides, on the rocks etc. It needs calcium to flourish.> The 3rd picture is a old empty turbo shell that has brown hair like algae and some kind of brown fuzz rug on it. Is this type of algae anyway good and how do I go on about of getting rid of it if it comes a problem? <Honestly I would pull it out right now and pull all of it off. That algae is terribly difficult to get rid of and it won't hurt the empty shell to just pull it out of the water.> Currently I quarantined my blue tang, yellow tang, 2 yellow tail damsel, fire damsel and clown fish because the tangs had a little outbreak of ich. The tank has been running with only 4 brittle stars, 4 Turbos and a cleaner shrimp. It's been a little over a week and my pod has 4x its population but then these brown hair started showing up as well. <No tangs to eat it would be my guess. As soon as they go back it should all disappear but you don't want to let it get ahead of you.> I've also notice some of my pods are turning red or maybe this is a stage in growth? I saw one of the red pods attached to another pod then two more pods attached on to the red pod...eventually the other 2 let go but I don't know what happen to the pod with the red pod on it. <I've never seen one that has red on it but its not out of the realm of possibilities.> Lastly, I was thinking about removing the filter trays and just left my sand rack and use the filter as water current to move the water, is that a good idea? I figured that those filter only trap poop and other debris and I could just buy a separate carbon pouch if needed. <I'm assuming you have lots of live sand and live rock in the tank to work as your filter instead? Should be okay if so. Lots of circulation is important to the tank.>

Coralline Algae i.d. Hi Bob. Could you describe in details how to identify coralline algae? Secondly, if these algaes are growing on the power heads, is it okay to remove them or ignore it? Please advice. Thanks. >> Don't know if I can... they're encrusting with CaCO3 base material... so, if you dry some, it'll turn white, foam with the application of an acid... have no pores (old designation, Nullipora, to distinguish...)... Do you have a microscope? Or, can you feel the matter with your hand? If it's hard, this IS likely some type(s) of coralline algae. Okay to ignore on most anything... would remove from viewing panels (gingerly, like with fancy commercial plastic scraper or credit cards), but that's all. Bob Fenner

Coralline Algae Bob- I was reading an article penned by you located at http://www.wetwebmedia.com/corallinealg.htm. I was wondering if there was any difference between the algae in your article and the encrusting coralline algae located off the coast of California? <Mmm, same groups down sometimes to the genus level as the tropical corallines... and both gorgeous. Dave Wrobel wrote widely on such "cold water reefs" incorporating these rhodophytes... still haven't caught on largely.> They look identical to me...but I'm wondering if they are. Thanks in advance. D.M. Daniels <Be chatting. Bob Fenner>

Yellow Spots... Maybe Algae, Maybe Encrusting, Not Definitely Coralline Bob - Thanks for answering all of our questions. I have yellow spots growing on the sides of my 75 gal saltwater tank. The spots are as large as a dime and start as a small dot. They have to scraped from the sides with my fingernail. Is this a type of encrusting algae? <Not a very encrusting variety if so...> If the spots were purple, I would say they were coralline algae spreading from the live rock. Any ideas? <Lots, but none re this organism or mix... Please read through the many materials posted on WetWebMedia.com re algae, their control, marine system maintenance. Bob Fenner>
-- Thanks

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Marine Aquarium Algae Control

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