Please visit our Sponsors
FAQs on Marine Algae Identification 26

Related Articles: 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: Algae ID Visual Guide, Marine Algae ID 1, Marine Algae ID 2, Marine Algae ID 3, Marine Algae ID 4, Marine Algae ID 5, Marine Algae ID 6, Marine Algae ID 7, Marine Algae ID 8, Marine Algae ID 9, Marine Algae ID 10, Marine Algae ID 11, Marine Algae ID 12, Marine Algae ID 13, Marine Algae ID 14, Marine Algae ID 15, Marine Algae ID 16, Marine Algae ID 17, Marine Algae ID 18, Marine Algae ID 19, Marine Algae ID 20, Marine Algae ID 21, Marine Algae ID 21, Marine Algae ID 23, Marine Algae ID 24, Marine Algae ID 25, SW Algae ID 26, SW Algae ID 27, SW Algae ID 28, SW Algae ID 29, SW Algae ID 30, SW Algae ID 31, SW Algae ID 32, SW Algae ID 33, SW Algae ID 34, SW Algae ID 35SW Algae ID 36SW Algae ID 37SW Algae ID 38SW Algae ID 39& Marine Algae Control FAQs 2, Marine Algaecide Use, Nutrient Limitation, Marine Algae Eaters, Culturing Macro-Algae; Controlling: BGA/Cyano, Red/Encrusting Algae, Green Algae, Brown/Diatom Algae,

New! FAQ, ID Visual Guide

New Print and eBook on Amazon

Marine Aquarium Algae Control

by Robert (Bob) Fenner

Help With Picture ID - Nuisance Algae 02/18/2009
Good morning,
<Good morning to you John. Mich with you today.>
I was wondering if I could get advice or help with id a picture of something growing on my rock.
<Will try!>
When I purchased the live rock from a local store, I asked the owner for advice on placing the rock in my newly set up tank. I said to just place the rock in the tank and everything should be fine.
<Can be the case, but isn't always. More here:
http://www.wetwebmedia.com/estbiofiltmar.htm >
Well now, I am wondering if I made the correct discussion.
<A QT tank can be your friend! More here:
http://www.wetwebmedia.com/quarinverts.htm >
A friend of mine said this was some kind of fungus growing on my rock and if is from not cleaning the rock before I placed it in the tank - I don't know.
<This is not a fungus. I suspect it is a nuisance algae that may have been deprived of light.>
Can you help?
<I hope so!>
Also, can you give me some advice on what to do if it is fungus?
<Please read here:
http://www.wetwebmedia.com/scottsh2ochgart.htm and related links in blue on the top of the pages.>
Thanks for your help. John
<Welcome! Mich>
75g with total of 115g system. 2x250w MH, 2xVHO, refug has 2xT5, some SPS, two LPS, and one fish.

Nuisance Algae or Sea Fan?? 2/16/09 Hi Crew: <Hi Bonnie, Mich here.> Attached is a picture that I hope you can identify. <Me too!> My reef tank is 3 1/2 years old. I have a deep 5" sandbed made up of crushed coral. I know, I know.....it takes a bit more maintenance than a substrate made of true sand, but I am diligent in stirring up the crushed coral a couple times a week and vacuuming the bed about every 3rd week. <Good husbandry can makes all the difference!> I recently removed about an inch of the top substrate and replaced it with new crushed coral. <You are wise, this will help your buffering capacity.> After I did this replacement, about 3 weeks later, I noticed this maroon, feathery growth. <May or may not be related.> It has continued to grow and is quite pretty. <I agree!> I thought, originally, it must be some type of sea fan. <Mmm, no.> However, I just want to make sure and not have some nuisance algae growing and getting out of control. <Does look like a Rhodophyte to me, but that certainly doesn't make it a nuisance! If it was mine, I would encourage it to grow.> It's very soft and feathery. Can you tell me what this is? <The photo is not clear enough for me to tell to much beyond it's a red algae, but it sure is a beauty!> Thanks for your help! <Welcome!>

Re: Algae ID?! 02/06/09
Hi Minh,
<Hello Brian.>
I apologize! I thought that I had sent you the pics. I did look on your site (http://www.wetwebmedia.com/trialalgaeid.htm) and a few you mentioned below but still can't find anything that is similar to it. Hope these pics are clear enough to get a good view! Please let me know!
<I'm sorry but I still don't see any attachment with this email. Could you try to resend the message with the pictures attached?>
Thanks again for your help!
<Cheers, Minh Huynh.>

Re: Algae ID?! 02/06/09
Ugggghh! Very Sorry Minh!
Here are some links to them in case they are getting stripped off.
Sorry for the inconvenience!! I really apologize!!!
<No problem, Brian. Technology can be so unpredictable. Well, I am finally able to see this algae and it is quite an interesting case! If it is indeed a type of algae, I don't believe I have seen this algal variant before. A typical long and white algae would be Acanthophora spicifera (http://www.reeflex.net/tiere/1619_Acanthophora_spicifera%20.htm) and the growth in your tank is quite different. Another possibility is a form of sponge like the Carteriospongia vermifera (http://www.reeflex.net/tiere/2202_Carteriospongia_vermifera%2002.htm). I will have to check with my colleagues and other resources to verify and get back to you.>
Thanks again,
<You're welcome. Minh Huynh.><<RMF's vote's on a Poriferan>>

Re: Algae ID?! 2/13/09
Hi Minh,
<Hello Brian>
Yea, it sure is strange! I'm not sure that it looks like either one. I'm thinking it looks more like a flat leafy type of algae as it doesn't resemble any type of sponges I've seen and the pics of the Acanthophora spicifera seem to be too spiky / spiny when this looks more feathery (but that could be due to the high flow area it's in). Someone did mentioned to me the possibility of Avrainvillea erecta. But I'm not too sure.
<Don't worry, I haven't forgotten about you. I've written a colleague about this and I am waiting to hear back from him.>
I am going to get a SLR camera from a friend and see if I can't get a really good shot of it. My next email to you will include the pic as well as my water parameters (which I conveniently left at home this AM - boo!).
<Excellent, I am looking forward to more photos of this growth and waiting on your tank water parameters.>
Again... thanks for the help!
<You're welcome. Cheers, Minh Huynh.>

Algae ID?! 2/5/09
Dear W.W.M Crew!
<Hello Brian. Minh at your service.>
Long time reader, First time writer. Just wanted to give a quick acknowledgment out to you all; *Thank you* for your great advice and knowledge sharing!
Well, I found these in my tank a few weeks ago. They started off as only one and now are multiplying and getting larger. It's a long-ish wispy looking algae with black fringe but mostly white and about 3-4 inches long. They seem to attach only to the back glass of my tank and none of the rocks. I tried many online searches but so far nothing that really resembles them. I'm thinking it is possibly some type of Cyano? But am probably wrong.
<Unfortunately, it is difficult to identify a type of algae by description alone as there are so many variants. It would be ideal if you could include a photograph for us to reference. However, I do have some tools for you to use to identify this growth yourself.
First, browse through "The Algae Page" (http://saltcorner.com/sections/guest/algaepage/algaepage.htm) to see if you could find a match. This page should have most of the common algal species found in the marine aquaria. It also contains some biological remedies as well.
Second, review this excellent article on micro-algal control: http://www.reefkeeping.com/issues/2008-07/nftt/index.php.
Lastly, a possible match for the growth on your glass could be dinoflagellates. More information can be viewed here: http://www.reefkeeping.com/issues/2006-11/rhf/index.php.>
I know my water quality is probably not pristine, but the levels are constant. My tank is a 72g bow front w/ 20g sump/refug, large Euro-reef skimmer, and two 150w MH. Bio load shouldn't be an issue as all fish are fairly small (antenna goby, Rainford's goby, target mandarin, yellow Coris wrasse, 2 Banggai, 2 blue/green chromis, hermits, snails) with sps, LPSs, softies, Zoas. I add Reef Builder and Advantage Calcium two times a week each on different days. I've asked on some of the different saltwater aquarium forums but haven't received a good answer, so I'm hoping you all could help!
<What are your water parameters such as temperature, pH, nitrate, phosphate, etc?>
Thank you again for the wonderful site and looking forward to your response!
-Brian from Boston!
<You're welcome. Cheers, Minh Huynh.>

Jelly but not brown? 02/03/09 I have a recurring problem with a jelly-like substance in my aquarium. I've tried to research what it might be, and all references I come across are to brown jelly on hard corals (with the advice to remove it in a hurry). However, the jelly substance I have is almost clear, not brown; perhaps a very faint yellowish is best description. <"Brown" jelly disease doesn't necessarily have to be brown... sometimes it's clear or beige...> It hasn't grown on any hard coral, though it has smothered a rock of polyps (despite frequent removal of jelly - eventually removal of rock and the colony to try to contain this problem). <This sounds like Cyano or, god forbid, dinoflagellates... but without a pic, I can't say for sure.> The jelly is present in a number of areas in the aquarium; it isn't limited to growth on specimens of any sort. It grows on some tufty algae, has invaded polyp colonies; can be found on bare but rough rock. High water current doesn't seem to limit it - there are no visible outbreaks in low light areas, though (which might just be coincidence). Siphoning off jelly in gobs is effective as a control, but can't be maintained long term. I've had the problem for several months, reoccurring in patches. Removing all rocks and specimens for individual treatment is a bit of a non starter, as the outbreak of whatever it is isn't linked to specific rocks or corals. (In fact, it hasn't appeared on any hard or soft corals, other than a polyp colony and sometimes where there are encrusting soft corals; my impression is that the infection isn't linked to these organisms, but they just happen to be there). <huh> So I'm unclear on what the cause is, or what to do to treat it. I really need some sort of pan-aquarium treatment rather than dips (of what I'm unsure), which would cause some massive disruption. From descriptions of jelly infections I can find, I'm not convinces this is the same thing as brown jelly (but there again, I utterly lack experience with this, although I've now kept marines for over thirty years). The aquarium is 2m long x 60cm square (about 6ft x 18in square) and mature; it is on the first floor with a hole cut in the floor to a garage below, where an identical aquarium is fitted with skimmer, heating and so on - so the water volume is quite large - before being pumped back up. Display tank has good water current and turnover. SG maintained at 1.025, 25 degrees. Any thoughts on any of this? Thanks for your time and expertise. <Try keeping the tank in total darkness for 2 or 3 days. If it's dinoflagellates, this will help... if not, well, at least it might give us a better idea of what this might be.> Chris <Best, Sara M.>

Black Filamentous "What" 01/31/09
Greetings from a relative newcomer to the field. I have been watching this "thing" on what I believe to be a Platygyra. It is black, and getting "longer" all the time. Very filamentous and feathery in nature. There are now what appear to be "air bubbles" appearing within the structure itself....two or three closest to the coral itself, and two individual "bubbles" equally spaced between there and where the structure becomes mostly filament. At present it is approximately 4 to 4.5 inches long and appears to be "growing".
<It's a kind of Cyanobacteria. In my experience, the type that grows like this (dark and stringy) is a real pain in the fins! I'd immediately check your parameters, do a water change, etc.>
The operative questions are: any idea what it is and if so, is it desirable, undesirable, or just "there".
<In my experience, in small amounts it's ok. But it can quickly grow to be a total nightmare.>
Thanks in advance.
Bob Wright
Sara M.>

Re: Black Filamentous "What" 01/31/09
Thanks very much...I check many parameters every other day, and those I tested are "in the green"...however its been a week since I checked phosphates. I will "get on it" before "it" gets on everything else!
<Yeah, it's just a beast! I had it myself once (uh, or twice) and it can be frustrating when it gets out of hand. It wouldn't hurt (never does) to run some extra activated carbon and/or a phosphate sponge...>
Sara M.>

Algae ID, Likely Diatoms 1/27/09 Hello crew, <Hi Mike> I have a 30g tank set up for a month now. For the past week and a half I have noticed this rust looking algae growing on my live rock and live sand. It hasn't really been a problem (I can only assume). Its now spreading all over the in and out takes of my filter (205 Fluval) and has almost completely covered my power head. I have looked all over your FAQ's on a bunch of different algae but I really haven't found one that hits home (sorry I'm more of a picture type person). The characteristics of it are as follows: On the sand it looks as if someone dyed it to a rust color, its not hairy or slimy looking, just a different color. I have 5 Turbos and a sand sifting star (which eat a lot of it daily). The rock and plastic in the tank literally look like they're oxidizing, the rock has all changed color. If I really have stumbled across the right answer then my assumption would be that its harmless and the bloom will subside when cycling is done and go away on its own? Now is where my questions come in. First off could it be that my temperature is too high? <No.> Its currently 80. I have done a 20% weekly water change and all my levels are zero. This stuff is growing extremely rapid and im curious to know if im doing something wrong. If it will subside does that mean it will go away entirely, if so usually how long after cycling is complete? <Mike, what you have is a diatom explosion and is not unusual in new set-ups. Keep up your husbandry and this will soon go away. See the link here and I'm sure the pics you see will be similar to what your are seeing in your tank. http://saltaquarium.about.com/cs/algaecontrol/l/blpicalgaediato.htm> I forgot to add I currently do not have a protein skimmer (I bought a cheap one and it makes way too many micro bubbles, everything I have done to get rid of them ended in disaster so out it went.) would this have any effect on algae? <On algae, oh yes. An efficient protein skimmer is one of the best investments you can make to improve water quality.> Thanks <You're welcome. James (Salty Dog)> -Mike

Slime Algae 1/18/09
Hello, I have spent hours reading on your website it is great.
I have a 55gal garden reef , 10gal refugium, cpr wet/dry with built in skimmer. The uv sterilizer and carbon only once or twice a month. For lighting I run a 8 bulb 432watt t5 light for 8 hours a day 2 hours of actinic before and after the 8 hour period. My water parameters seem to be right ph 8.3 calcium 400, magnesium 1300, nitrites, nitrates, ammonia and phosphate all at 0. I have been having a problem with some type of slime covering everything, I have scrubbed it off several times. I have three 400gph Hydor Koralia for water movement with 500gph return pump. My sand bed is only about 2-3 inches deep and gets stirred up by my clownfish a lot I was thinking maybe this was causing the problem but I wanted to ask the pros.
<Crud on the sandbed is indicative of other issues, but for what it is worth this really should be increased to 4-5' for a true DSB or reduced to 1' or less for cleaning. The middle ground tends to accumulate detritus and nutrients without any benefit.>
I have 5 SPS's, frog spawn, elephant ear mushroom, brain coral, crocea clam and several trumpet corals. My refugia has Caulerpa and Halimeda plant in it. I have a sebae clownfish, tomini tang and a damsel. I do 5 gal water changes every week. Sometimes when the sand gets stirred up I can see black spots in it when you stir the black spot up its like dust. I have included a photo of the slime.
I appreciate you taking the time to read this and any suggestions on what to do to get rid of this or maybe just what it is would be great.
<The fueling factors are introduced somewhere, either feeding or source water. Your levels test OK because they are being consumed as produced. Do see http://www.wetwebmedia.com/bluegralgae.htm and the linked files above. All the solutions to your issue are held there within.>
Thanks for the help and such a great website Dan

Hey Crew
Re: Neglected tank, algae run a muck 1/4/09
I have been looking on your web site all day, and found a wealth of information, however, not quite what I am looking for. I have a 75 gallon reef with a good amount of live rock. It has been set up for 5 or 6 years.
I went through a period when I didn't take care of it the way I should have and I have an algae problem. I also have a 20 gallon refugium with Caulerpa, and I can't remember what the other stuff is in there. I think it is Chaeto.
<Most likely Chaeto if it looks like green spaghetti. Do be careful with the Caulerpa though. It's one nasty bugger if it goes sexual on you or gets in your main display. Here's some information to ID if you have time http://www.sccat.net/#identification-1e86f5>
I have some hair algae in the refugium also, but that is not may main concern. In the display tank there is a brush like growth that I think is Chlorodesmis, based on the pictures I can find.
<A picture would be best to see here, but I have doubts that you are dealing with Chlorodesmis aka maidens hair algae.>
I have read that it is a difficult algae to grow, so I am not sure that is it. It will grow Large clumps in my display tank. I have tried to manually remove as much as I can, and have started keeping the tank better, keeping the water quality up, cleaning, watching the chemistry. But the algae seems to still grow abundantly. It grows so thick that it traps solid waste near the rock it grows on and acts like "potting soil". The only think I am not totally sure about is the phosphate level. I have trouble distinguishing the color on the test kits. The other levels test 0 for ammonia nitrate and nitrite. I know from other articles that there could still be some level in the tank, but it gets used quickly enough so it doesn't show up on a test.
I am wondering it there is something I can put in the tank to control this stuff. I have a candy coral that I had to separate into smaller pieces to remove some on the algae that was killing a portion of the coral.
Thanks for any input you can give me.
<Again, without a picture it is hard to say, but if it looks like maidens hair, I would think it is probably Bryopsis or hair algae. Bryopsis can look like ferns or more like hair algae with tiny hairs growing off the central hair shaft. Its very hard to get rid of. There are a few things you can do if it is Bryopsis. I've heard of a few things that work most of the time, and only one that works all of the time. Ruby lettuce Nudi's will eat it all, but then you must take care that they don't starve and either return them to the local fish store or pass them along to someone else in town who has an algae problem. You must also be careful of powerheads because they will enter them and get ripped apart. I've also heard that raising magnesium works, but it is hit or miss. You can find some more information on the subject here:
Algae control in general
Specifics on Bryopsis
Regards, Jessy>

re: Hey Crew 1/4/09
Here are a couple of pictures to help with ID.
I don't see anything that looks remotely like something coming off the main shaft.
<Mmm, looks like Bryopsis sp. to me... a tough Green algae to control...
See the Net, WWM re probable approaches. Bob Fenner>

Red algae growth... BGA, reading 12/26/08 Hi there. I've been battling some type of red algae growth in my tank over the last few weeks and would like to know if it is harmful or not. <Can be> If so, what measures should I take to get rid of it? <A few approaches...> Even if it's not, how could I control it? It quickly spreads over all the substrate of the tank as well as the live rock. I tried to identify it using the pictures on this site but couldn't find anything that looked like a perfect match. The algae will peel up in sheets off the substrate once it has grown for a little while. Here's a picture of it after about a week and a half after I cleaned it up last: >... is BGA, aka Cyanobacteria. Read here: http://wetwebmedia.com/bluegralgae.htm and the linked files above. Bob Fenner>

Thanks so much for the help! All I needed was a definitive ID on that stuff. <Ahh, welcome... Not hard to "nip in the bud" when caught early on... Good luck. B>

New Print and eBook on Amazon

Marine Aquarium Algae Control

by Robert (Bob) Fenner

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: