Please visit our Sponsors
FAQs on Marine Algae Identification 25

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 6Marine 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 18Marine 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 26SW Algae ID 27, SW Algae ID 28, SW Algae ID 29, SW Algae ID 30, SW Algae ID 31, SW Algae ID 32SW Algae ID 33SW Algae ID 34SW 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

Cyano or dinoflagellates?  8/26/2009
Howdy guys,
<Evening, Mike here today>
First the stuff I know you'll need! ...
75 gallon tank
SG 1.025
temp 76
ph 8.2
ammonia 0
nitrites 0
nitrates 10
phosphates 0
inhabitants: pair of false Percs, yellow watchman goby, Kole tang, one spot Foxface, Zoanthids, star polyps, colt coral, mushrooms, frogspawn, assorted
crabs and snails.
With that out of the way, I'm having a problem with "something." I thought it was Cyano, but after reading some, I suspect it may be dinoflagellates.
This stuff grows in long wispy strands and there are a few places on the live rock where it seems to be bubbly. The substance in question is rather brown or dull dull red in color and isn't necessarily growing in sheets.
However, I had read that dinoflagellates will actually grow on the surface of the water? I certainly haven't seen anything like that in the tank. I certainly don't think circulation is a problem...the tank should be turning
over about 30x per hour (I took it seriously when you guys say its hard to get too much circulation!). My lights (4x54 T5 HO) are on 12 hours per day. The fish seem to eat everything I put in the tank, and I try not to get any of the frozen food juice into the tank.
The tank is still fairly young (been cycled for about 4 months). I got an obligatory diatom bloom a few weeks in, which was replaced by some hair algae, which has begun to die off. I remove as much of the hair algae as possible, but it has proven difficult to get all of it off of the back wall of the tank. Is the dying algae contributing to the Cyano/dinoflagellates?
I'm doing 2 8% water changes per week, and have been since the hair algae started showing up.
<Why does seemingly everyone perform such small partial water changes? Try for 50% bi-weekly instead!>
All water is RO-DI mixed with Kent salt. Is this just something natural that I should work through, or is there something else I should be doing other than trying to vacuum up all of this stuff that I see? This stuff has been around for a few weeks now, and it doesn't seem to be getting any better. I'm always paranoid about my test kits being faulty so I also had the LFS test my water and they got the same param.s. Any guidance you could offer would be greatly appreciated!
<Parameter tests can be misleading in cases such as these - if your phosphates were truly zero, your algae couldn't survive. Instead, it's being used as a nutrient source, and sequestered. Your #1 weapon is always going to be nutrient control, which can be accomplished by large and frequent partial water changes, aggressive protein skimming, and by the use of chemical medias such as Purigen or Phosban>
<Mike Maddox>

Identification - Red Algae of sorts... reading   12/14/08
I'll try to identify the best I can without pictures.
<In this day and age... better to send images along>
I have what appears to be a red algae, not like the Cyanobacteria that I have been reading about. This specimen has not been spreading to my gravel at all, but rather on top of many of my rocks and growing almost like it is in shelves.
It has been spreading rather quickly. I have removed it once from all of the rocks, and when it comes off it comes in chunks and then leaves a lighter color underneath. I removed most of it and changed water, and cleaned filters, but it has come right back. I'm having a difficult time getting control over it as I don't know exactly what I'm dealing with. Any help you can give is most appreciated. Please keep up the good work!
Thank you,
<Please peruse here: http://wetwebmedia.com/marinvind1.htm
the files linked at top... Algae Identification... and the links you lead yourself to in turn. Enjoy the learning, tool. Bob Fenner>

Re: Identification - Red Algae of sorts 12/14/08
Thank you for the reference. I actually went through that page prior to emailing you and couldn't find an image that resembled what I thought I had. I'm attaching some photos this round so hopefully you'll be able to help me correctly identify what I have so that I can treat it accordingly. Thank you for the resources that you have created!
<Ahh, and thank you for sending along the attached pix. This is assuredly Cyanobacteria... Blue Green "Algae"... there are a few approaches to its control... Please read starting here:
and as much of the linked FAQs files above as you require to familiarize yourself with your options...
Cheers, Bob Fenner> 

Coralline or Red or Brown Algae Problem (None/ Is Cyanobacteria)  12/11/08 Hello, <<Howdy>> I have a 100g reef tank w/ 110 lbs live rock, as well as 2" live sand. Tank has been set up for 6 months now. Mechanical filtration is skimmer & Fluval canister (only using Purigen bags in it). Bioload is low. My problem is a purple algae that is blanketing my entire tank. Even my green polyp corals are covered by it. The algae presents itself as a thin blanket. <<Mmm'¦>> It is easily dislodged by a turkey baster (blows off instantly) but it is right back the next day. None of this algae is attached to the glass - just on the rocks & sand. <<This is not actually a true alga'¦ What you have is Cyanobacteria>> My problem is I don't know if this is true coralline algae (it is purple in color) or a shade of 'red' or even 'brown' algae. <<Though referred to as Blue-Green Algae, Cyanobacteria can manifest in an array of colors>> This makes it difficult to do a Google search as I don't know exactly what type of algae (purple, red or brown) I am dealing with. <<Try searches on Cyanobacteria and Blue-Green Algae>> My hunch is Coralline algae does not take the form of a thin blanket that is easily dislodged & floats off still in blanket form. <<Indeed>> But I am not sure. Based on my description, any idea on which type algae this might be? <<Yep'¦ As stated>> This algae has been present now for approx 3 months - but it is getting worse. <<This is not atypical with this nuisance organism. Eradication can be difficult... You need to determine what is contributing to this outbreak. Look to things like your source water and foods/feeding methods for possible introduction of excess nutrients. Ensure the system is optimized (pH, Salinity, chemical balance) for your desirable organisms to help them outcompete the Cyanobacteria, and consider adding an in-line vegetable refugium for this same purpose (among other benefits to your system). You might also want to think about changing the depth, on way or the other, of that 2-inch sand bed. 2-inches is not an optimum depth as it is generally considered too shallow for proper denitrification processes and too deep to prevent accumulation of nutrients (though admittedly, some hobbyists do make such depths work). You should also do some reading. Start here, and then follow the associated links in blue at the tops of the pages: http://www.wetwebmedia.com/bluegralgae.htm >> Thanks, bw
<<Happy to assist. EricR>>

Xenia... Valonia removal - 12/06/08
Hi my name is Jamie
<Hi Jamie. My name is Michelle.>
and I bought a frag of xenia from my LFS
<Wow! You actually bought Xenia? Just teasing, but many people can't get rid of the stuff, so it is often given away for free.>
and when I got home I noticed there was this green bubble under one of the three stalks.
<Sounds like Valonia, also called green bubble algae, which you'll want to remove manually.>
I have attached a picture for you.
<A SUPER TINY picture!!! Let me get out my microscope so I can see it!
Mmm what do you think a 100x magnification? Heehee!>
Can you help me identify this problem?
The one stalk looks like its halfway mounted onto the green bubble.
<Remove the Valonia, the Xenia will reattach. Try to extract the Valonia without actually breaking the bubble itself, otherwise you increase the risk of spreading it.>
If it is green bubble algae, how do you suggest i remove it without hurting the xenia?
<You can easily cut the Xenia with a single edge razor blade. Don't worry about hurting it, this is often how it is propagated. Xenia seems to be one of those things that you either can't get to grow or can't stop it from growing. If I were you, I would keep this coral isolated on the sandbed like you show in your photo, because Xenia can be very difficult to remove from live rock to which it might spread.>
<Cheers and happy propagating!

Re: Xenia... Valonia removal 12/12/08
Hey just responding to your information and I wanted to say thanks!
<You're most welcome Jamie.>
I removed the green bubble algae and the Xenia is doing great!
<Wonderful to hear! Enjoy the Xenia, is one of the coolest corals out there in my book!>
<Cheers, Mich>

White Fluffy Something growing in tank... Mmm, not a Three Musketeers Bar  12/4/08
Hello guys
<Ya got one of the gals tonight.>
I don't think I have written before,
<Well, don't worry, we don't bite... too hard.>
but I am really curious about this:
One of my saltwater aquariums is a 2 year old 29 gallon tank a couple of weeks ago I noticed this fluffy white thing growing.
<Blurry, but I see it.>
I have no fish or corals in the tank, I just grow coralline and tons of pods in this tank (and a couple Aiptasia).
<Would be interesting to observe long term to see what grows when predators are limited.>
The other white spots in the photo seem to be some type of tube worm.
<Yes, they are spiral tube feather dusters or Spirorbids. Nothing to worry about. Enjoy the diversity.>
Most things in this tank are completely covered in pink Coralline.
<Very nice.>
Water is 80 degrees
<I prefer closer to 78 degrees Fahrenheit.>
Calcium is 420
pH is 8.4
S.G. is 1.0244
Alk 170ppm
about 25 pounds of live rock and 2.5 inches of aragonite.
lighting is one normal florescent tube left on 24x7
Can you all tell what this is growing on the heater?
<I think it might be an algae, perhaps something like Hypnea cervicornis, but the photo is rather blurry, so that's more of a guess than an answer.
Almost looks like those Magic Rocks I had as a kid, they were made of metallic salts, white being calcium chloride.>
I have looked everywhere and can find it. It may not be showing, but there are a couple tubular nodules within the fluffy mass and seems to hang tight in the crevice of the heater. I don't see it anywhere else in the tank.
<Sounds even more like an algae.>
<Welcome Mich>

Heee! RMF

White Fluffy Something growing in tank... 12/05/08
Hello guys I don't think I have written before, but I am really curious about this:
<HI, sorry it took so long for you to get a response. Sometimes our crew members put emails in their folders and "forget" about them for awhile.>
One of my saltwater aquariums is a 2 year old 29 gallon tank. A couple of weeks ago I noticed this fluffy white thing growing.
I have no fish or corals in the tank, I just grow coralline and tons of pods in this tank (and a couple Aiptasia).
The other white spots in the photo seem to be some type of tube worm.
Most things in this tank are completely covered in pink Coralline.
Water is 80 degrees, Calcium is 420, pH is 8.4, S.G. is 1.0244, Alk 170ppm, about 25 pounds of live rock and 2.5 inches of aragonite.
lighting is one normal florescent tube left on 24x7 Can you all tell what this is growing on the heater?
<It's difficult to say from the photo... the light is making it way too bright. Can you retake the photo with the overhead lights off? ..maybe with the flash?>
I have looked everywhere and can't find it. It may not be showing, but there are a couple tubular nodules within the fluffy mass and seems to hang tight in the crevice of the heater. I don't see it anywhere else in the tank.
<My first thought was that it is a sponge. But, again, I can't really tell without a better photo... sorry. :-(>
<De nada,
Sara M.> <<This too was resp. to... Likely the Rhodophyte Hypnea... see SW Alg. ID recent FAQs page. RMF>>

Encrusting brown algae   11/28/08
Thanks for your great website. I wondered if you could give us some advice about algae.
<I'll certainly try>
Unfortunately we don't seem to have much luck with encouraging coralline algae to grow in our tank.
<Mmm... to refresh/re-state... this may be due to a lack of alkaline reserve and/or biomineral mix/balance (takes both), competition and predation... or conditions that favor competition...>
Over the past two years we've fought off growths of diatoms, red slime, red bubble algae, Caulerpa, and hair algae, but the coralline never really takes hold.
<I wish I could give you my "pitch" on RedOx... I'll bet yours, and the conditions that promote/allow it here are largely at fault>
Now we've got some purple coralline growing in there, but mostly what's taken over since our Rabbitfish bumped off the hair algae is the encrusting brown stuff in the enclosed pictures. It grows in circles on the back of the tank and encrusting on the rocks. It's sort of rust-brown color, sometimes with lavender spots in the center and/or white hairs on top.
<I see it... unfortunately does appear to be the Brown/Phaeophyte, Lobophora (likely variegata)... not easy to control:
Do you know what this is, if it's bad for the tank, and if so how to get rid of it? Our Rabbitfish shows no interest in it.
<Can be bad... in that it proliferates, covers over space you'd like to have for other purposes... is largely unpalatable... Needs to be addressed by competition, physical removal, chemical and physical filtration... the Other pic is a mix of greens and BGA... evidence of low RedOx, too much nutrient, lack of circulation/aeration... You'd do well to spend some time perusing WWM re Algae...:
http://www.wetwebmedia.com/marine/maintenance/maintindex.htm toward the bottom. Bob Fenner>
Thanks for your time!

Algae or what ?, SW, no image... 11/20/08 Hello, this is Abdul. <Hi> Suddenly, my saltwater aquarium is getting this brown thing all over it. It's on the wall, on the sand, on the live rock, it's every where. Please help me on this. What is this and what should I do to get rid of it. <Most likely either diatoms or Cyanobacteria. Both can be controlled through nutrient control. See here and related FAQs for more http://www.wetwebmedia.com/bluegralgae.htm .> My tank is three months old setup of standard 50 gallon with two 30 watts florescent tub lights and one 30 watts aqua blue tub light. <Both are common in new tanks.> Lights remain on from 10 am till 10 pm and tank is also exposing to good quantity of sunlight as well. I have one sea star, five hermit crabs, one watchman Gobi, two domino damsels, one frogspawn coral, assorted colony polyps and live rock." Regards, Abdul Hadi Dar <Both diatoms and Cyanobacteria can be controlled by implementing good maintenance and water quality procedures. All are covered extensively on WetWeb's articles and FAQs.> <Chris>

Mysterious Fungi From the Blue Lagoon, Rhodophyte? ID  11/15/08
Hey Guys!
Its been a while since I've written in, you know why? Because thanks to you, I have had a well balanced tank which hasn't had any problems to speak of!!! :D
My name is Josh and I have a 20gal slow growing reef tank, which according to your advice I have moved out old incompatible livestock and am slowly building into a thriving community. Slowly, because I am college student spending my financial aid wisely lol.
<Man! As a college student, I could barely afford Top Ramen!>
Anyway, I got some live rock about 8 months ago and over the past month or so I have started having a creature grow that I'm not really sure what it is. It is a slightly translucent red color which kind of resembles a mushroom group normally found on trees, with many layers up and down the side of a rock. Its ends kind of resemble a bad drawing of a glove with little round short fingers. It is non-calcareous, and completely photosynthetic and doesn't react to touch. Over the past month it has grown from a tiny red spot to about a 2 inch long, one inch wide patch, since I am doing a better job at supplementing the small corals currently present.
It is reaching hard for the light but it shares a rock with a red mushroom which I don't think I should move any closer then where it is, the bottom.
It doesn't seem to be hurting anything but I am dying to know what it is.
Hopefully the description is enough, because my camera is broken, but if you need a pic, I will track one down.
Thanks for all the support!
<A pic would help... this is most likely a Red Algae (see here:
http://wetwebmedia.com/redalgae.htm, and the linked files above), or a sponge. Do please send pix along. Bob Fenner>

Algae ID Please 11/13/08 Hi guys, <Hello.> Please help us identify our algae growth. We have looked at tons of pictures tonight but can't seem to find any that are the same. The first one is growing among plants on live rock we think this is green hair, the second we think is the same growing on a plastic anemone. The third algae is a brown/rust color film growing on the substrate (this was given to us and I believe it is live sand). There is also a film growing on the glass this is visible in the second picture. The tank was recently moved to a room with less sunlight about 3 weeks ago will this help or harm the algae growth? <It can help your battle against it.> Do we have good or bad algae on our hands? <Sounds like BGA, diatoms and/or hair algae. The procedure to rid the stuff is all the same anyhow. The attached files are actually shortcut attachments, not the pics themselves.> Our tanks specs are as follows: 30 gallon saltwater set up for about 9 months filter: AquaClear Power Filter 30 gallon Sea Clone 100 Protein Skimmer,  lighting: Aqua Ace Bioplant 20W, Livestock: 2 green spotted puffer (approx 2"), 1 clown fish (approx 2"), 1 damsel (approx 2"), a lot of bristleworms (we now know what they are thanks to your site) We also had a piece of live coral but it has died and the algae is growing on it now too. (This won't come back will it?) <Not if completely gone.> Any help or suggestions on our algae problem is greatly appreciated. <Follow this link: http://www.wetwebmedia.com/algaeconMar.htm.> Thanks in advance. Colleen and Allen <Welcome, Scott V.>

Please Help Me ID This: Rhodophyte  11/11/08 <Hi there, Kimberly> I have been trying to ID this red growth in my tank for over 2 weeks now...Do you have any idea what it is??? <It's a Rhodophyte/Red Algae of some sort, but I haven't been able to narrow it down. I'm still looking though! I see that you've posted a question regarding this over at the forums (at this link: http://bb.wetwebmedia.com/viewtopic.php?f=25&t=1265 ). I'll be glad to do more research and see if we can't get this mystery solved for you!> It kinda looks and feels like a mushroom, some think it's an algae. <Yep, that's what it looks like to me too.> I'm trying to find out if it's good or bad....It looks pretty neat. <I agree. I'd enjoy it, but keep an eye on it. If you start noticing any great leaps in growth, or see it spreading to other areas of the tank, then I'd opt for pruning/manual removal.> In the picture the bunch of whatever it is, is about an inch wide and half an inch long, and it seems to be a colony of some sort. Any information is appreciated! <Sure hope we can ID this for you!> The tank has been set up for a little over two years, I have great success with mushrooms (most open to about 4-5 inches across), <Wow, I bet that's pretty.> I'm really not having any problems with the tank and all my corals seem to be very healthy. <Excellent - a testimony to your good care.> My coral collection consists of a green brain, a finger leather, several different types of polyps (orange, brown, Cinnamon, and bulls eye), Mushrooms (green striped, purple, a very light pink, green anemone mushroom, & several Ricordia), torch coral, purple sea whip. My fish include a Maroon Clown, 4 Damsels, Lawnmower Blenny, Green Clown Goby, & Bi-colored Blenny. I have an AquaC protein skimmer, 3 power heads for circulation. I'm running power compact lights. Thank you for your help! Kimberly
<My pleasure! Take care, Lynn>

Live Rock Growth: Neomeris annulata - 11/8/08 Hello, <Hi Beth> I hope you can help me with the identification of some "things" that have grown out of my live rock recently. This is in a 35g tank that has been setup for 8 months now. I have spent a lot of this time watching what comes and goes on the live rock, and have been able to identify most things, but have had no luck with these. They are segmented tubes that are white, shading to a bright green on the upper half. There are fine hair-like feathers on the outside of the tube, growing from the last four to six segments completely around the tube. The tip of the tube is completely closed. I mention this because when these first appeared, I thought that they might be feather dusters as the tube is somewhat similar. These are also stationary, and do not retract or react in any way like a feather duster would. The first of these appeared about two months ago, with the others following within two weeks or so. Within that time, the largest has grown to be approximately 2.5" long with a diameter of a 1/4". I have attached some pictures that I hope will help in identifying these. Any advice that you may have regarding whether or not to leave them alone or remove them would also be greatly appreciated. <What you have is a beautiful little calcareous green algae called Neomeris annulata. Thankfully, it's not a species that tends to get out of hand but if necessary (or you find it unsightly), control can be achieved through manual removal. Please see WWM for more information regarding, starting here: http://www.wetwebmedia.com/greenalg.htm, and/or enter "Neomeris annulata" in our Google search engine: http://www.wetwebmedia.com/WWMAdminSubWebIndex/question_page.htm > Thanking you in advance, Beth
<You're very welcome. Take care, Lynn>

<<cool pics -Sara M.>>

Brown algae?   10/19/08 Hi guys, How are you going? <Great here.> I'm trying to work out whether or not this ghastly sight I have in my tank is brown algae. If it is, please let me know what else I can do. The "dirtiness" first appeared yesterday when there was just a slight brown tinge to the calcium carbonate substrate. Today, it has taken over most of the surface of the substrate and is now taking over the upper layer of live rock. <Sounds like BGA/diatoms rather than an actual algae.> After doing a little research on the internet, I found out that this algae is fed by light and silicates. Not knowing much about silicates, I have eliminated the light source. Light was on for 12 hours each day. <This treat the symptom rather than the cause.> So far, I'm up to day 6 of cycling my tank. <Ahh, the cause!> The water parameters are as follows:- pH - 8.2 Ammonia - 0 Nitrite - 1 Nitrate - 10 Phosphate - 0 Calcium - 380 dKH - 11 SG - 1.022 <Should raise this to 1.025-1.026.> Temp - 26.3 deg C The tank is 200 litres with an 80 litre sump below. When I first started, I used a bacteria booster and some flake food to help get the cycle going. <Neither helps IMO.> I have a tiny snail in that tank which hitched a ride on the live rock. <Neat.> If you could advise on what I should do, that would be much appreciated. <First, do realize the difference between cycling and curing live rock; the terms are used interchangeably and are actually different. http://www.wetwebmedia.com/ca/volume_2/cav2i3/Live_Rock/live_rock.htm After sorting through this article you will likely agree that some water changes are in order. After that a period of patience/waiting.> I would have taken some photos except the camera that I have doesn't make very clear pictures when I try to take photos of the tank. <No problem, sounds like a common issue.> Thanks for all the help and advice. I look forward to your reply, Nick <A bit of time a normal growing pains, Scott V.>

Unidentified Algae... reading  10/16/08
I have had a recent crop up of several unidentified algae in my 30 gallon reef. I would appreciate some identification assistance, and some courses of action.
Unfortunately, I had difficulty taking clear photos of the suspects, but hopefully you can make them out.
<I see them>
The first algae is a long green worm looking thing, as they get longer, the bottom turns white. There are 5-6 of these scattered throughout the tank. I think this is probably
<Mmm, maybe... the second pic on the right is very likely a Neomeris sp.>
The second is a dark green growth, with small fingers or branches all over it. There are several patches of this growing in different parts of the tank. This is the one I am most concerned with identifying. Unfortunately its also the ones with the worst photos.. Its possible that this is
<Mmm, some part of the first, fourth and fifth photo appears to be a Codium sp.>
seem to have many more (very short) fingers with a darker color.
Another algae is growing from inside of one of the patches of the previous item, and looks like blades of grass
<I see this, don't know what this is>
The final is I believe a standard bubble algae, that I will try and vacuum out during my next water change.
<Is a Valoniacean...>
You can also see several aiptasia, which have been a long term issue for me.
I can't manage to eradicate them. I kill em down with Joe's juice when they get unruly, but a few months later they come back and I do it again.
For the algae, are any of these particularly worrisome?
<... see WWM re these genera... the search tool, indices>
Will they damage other items? Do I need to try and scrape/vacuum them? Are any beneficial?
Thanks for your time and Assistance,
<Thank you for helping yourself. Bob Fenner>

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: