FAQs on Marine Algae Identification
Related Articles: Avoiding Algae Problems in Marine System,
Control, Marine Maintenance,
Nutrient Control and Export,
Marine Scavengers, Snails, Hermit
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"/(Cyanobacteria), Diatoms, Brown
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 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 34,
SW Algae ID 35, SW
Algae ID 36, SW Algae ID 37, SW
Algae ID 38, SW 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,
Pesky Sea Weed 1/7/11
In the last couple months I have had this pesky weed showing up
in my aggressive tank. What is it and is it good or bad and if
bad how do I get rid of it.
<Hard to say. What is going on? Feeding, system, filtration,
Thanks for your help
get rid of it?
<Please, pretty (I am sure you are) please, start here:
Algae ID -- 12/28/10
First, may I just say thank you for putting together such an
informative website. I have looked across your site to try and ID
the algae I have in my 20g Nano. It covers the substrate and
<Yes. Tis a Cyanobacteria...>
I have attached a photo and a very brief video which shows the
algae more clearly. Is it a problem algae and should I take steps
to remove it?
<Yes I would. Toxic. Please read here: http://wetwebmedia.com/bluegralgae.htm
and the linked files above...>
<As many welcomes. Bob Fenner>
Re: Algae ID 12/29/10
Many thanks for your help!
<Very glad to aid your efforts James. BobF>
Algae (?) ID 9/11/10
I have two (new) unidentifiable "things" growing on my
tank glass. The first (photo 2.jpg) appears to be a green
filamentous algae; however, I'm not sure and wanted to
<Can't tell from your images... do you have a
The small "clump" is anchored by a brown dot (if that
helps). If it is, should I scrape it away? Or let it be?
<I'd do the latter. Will likely "pass" of its
own accord in succession>
The second object (photo 4.jpg) is a small white dot with what
looks like filaments coming off. They kind of look like really
really tiny brittle stars.
<These are Hydromedusae... See here: http://wetwebmedia.com/hyzoidf5.htm
Maybe hatching pods for little crustaceans (I have a lot of
amphipods crawling around on the glass as well, though know
Just so you know, I don't have any brittle stars in my tank.
Well, not that I know of. I guess something could hitched a ride.
Sorry the picture is a bit blurry, but they're really
Thanks for all your help! You guys rock!
<Be chatting. Bob Fenner>
Re: Algae (?) ID
I do have a microscope!
<Figured... w/ the .edu suffix...>
Unfortunately it's not set up with a camera, but I was
able to take some pictures through the scope with my camera
that are ok, though the light isn't the best. Sorry for
that. Since I wrote you yesterday the algae has definitely
become more established, though it's still just on the
glass. I'm guessing it's a Cladophora, though
definitely much smaller than most of the pictures I've
seen (the scale in the scope view is mm), so may also be a
type of Bryopsis?
<Mmm, maybe... a uniseriate branching Green/Chlorophyte
in any case>
Your help is much appreciated.
Red Circles 9/6/2010
Thanks again guys for all of your help. I just have a quick question
about my tank. When I bought it from the guy who owned it first it had
these red circles on it. I was able to scrape it off and clean it well.
I've had to clean it about every 6 months now. It's not soft or
hair-like. It's hard red circles that range in size from tiny to
quarter sized. A fingernail can
take them off with enough effort but I use a metal scraper. They grow
very low in the tank. either just above or below the gravel line. Any
idea what they are, what causes them, and how to get rid of them for
good. They do not seem to be affecting the fish and my nitrates all
seem to be in order.
I did have a random ammonia spike recently from removing some fake
ornaments and replacing with more driftwood. (wanted to make my tank
more real). The spike has returned to normal since then. Thanks
<This sounds like calcareous red algae, sometimes called coralline
Common in marine tanks, but as far as I know not found in freshwater
Usually they are in areas where there is bright light, so having them
grow below the gravel is weird. So they might be something else,
perhaps another type of red algae like those called spot algae. Spot
algae is usually green to blue-black, and notoriously difficult to
remove because it adheres to the glass so well. Again, a cosmetic issue
rather than anything more serious. In any case, if you can wipe them
off the glass, they're unlikely to be anything toxic, so I'd
not worry about them too much. Cheers, Neale.>
Strange White "Hair" on Rocks
Hello Wet Web Crew,
About two months ago, I bought 3 pieces of "base rock"
that looked like white manufactured rock, even though it was said
to be "Reef Rock" (from reefcleaners.org). Silly
enough, I cycled it in water for two weeks, just in case there
was anything living on it that could be harmful to my
Anyway, to get to the point, during the last week, (only) these
three rocks have sprouted what looks like 1/4" clear hairs
everywhere on them (see photo). The "hairs" sway in the
current and almost look like a velvet fuzz.
My tank has been established for 2+ years, without any new
additions in the last few months except these rocks. Any idea
what the "hair" is and if it could be harmful to my
fishes and corals?
<Is likely an algae or mix of algal and Protists... not
harmful... and will "go" of its own accord in
Also, I've checked all of my tank conditions and all seem
fine (Nitrates are close to 0 most of the time due to skimming,
water changes, etc, so I am in doubt of it being a bad algae even
though it could be).
Any help in identifying this would be greatly appreciated!
<A microscopic examination would very likely be more
definitive, but barring such investigation, I would not worry.
Algae hitchhiker ID: Acetabularia crenulata
Mermaid's Wineglass 7/26/2010
Check this out........I just spotted this in my fish only
It has no live rock or substrate, or should I say it was started
<Looks like some crushed shells in any case.>
What is it, I assume a plant/algae of some kind.
<It is an algae, and a relatively rare one (in the pet
It is Acetabularia crenulata, or commonly known as mermaid's
wineglass algae. A nice find!>
<You can read some about it here:
Algae Control, reading 6/15/10
Hello crew. I need help with an algae problem. I have a
28G Nanocube that has been running for about 6 months.
I have been struggling to control algae for most of that time.
<Small volume/systems are hard to maintain... harder than
Right now I have three types of algae that are out of control. The tank
looks like a jungle. The first is short brownish 'hair' with
gas bubbles at the tips. I believe this may becalothrix Cyano from the
research I've done. This stuff covers most of my live rock. The
second is a bright green slimy film which grows very quickly over my
substrate. It peels off in layers taking a good amount of substrate
with it. The third is long brown 'hair' algae.
Here is more information about my tank. Ph is 8.1. Ammonia, nitrite,
nitrate, and phosphate are all zero. These have been confirmed by my
LFS. I have about 20 to 22 lbs of live rock, and livestock consists of
a clown and a scissor tail goby.
Based on research, I've tried the following to control the problem
with no success:
- Shortened my lighting cycle from 12 hrs of daylight to 10 hrs per
- UseRODI water (have been doing this since my first water change after
tank was set up)
- Increased frequency of water changes from once every other week to
once per week. I typically change 3 gallons, but increased to 4a couple
of weeks ago.
- Decreasedthe amount of food put into the tank.
- Physically removed rocks from the tank and scrubbed. The rock looks
good immediately following this, but the 'gasbubble' algae
- Physically harvested the long hair and green film as best I could,
but again it returns in 24 to 48 hrs.
- Lastly, I installed a HOB skimmer last week. It's been running
for about 4 days since break-in and is pulling a nice amount of tea
colored skimmate. So far the algae'snot been affected, but it may
be too early to tell.
About the only thing I don't have is a cleanup crew, although I
don't see how a handful of snails and hermits could make a dent. I
had a lawnmower blenny which died recently (he was my favorite) -- he
did a good job on the long brown hair algae but wouldn't touch
anything else. My LFS suggests using a chemical
but that won't address the root cause whatever it is.
I'm running out of options -- what more should I do? Thanks.
<Read here: http://wetwebmedia.com/avoidingalgaeproblesm.htm
and the linked files above... esp. re DSB's, Refugiums, Nutrient
Export... Bob Fenner>