Another Attack of Algae...

[catshanon]

This is how the top of my planted tank looks. Its so unsightly and it keeps coming back. Is this cyanobacteria ? Cyano is supposed to be slimy and blue green, but why is this stuff bubbly ?

Any suggestions of removal and identification is most welcome.

Conditions:

pH probe controlled CO2. pH is at 8.0.

Plants are growing healthily, although hair algae is present inside the tank.

Irregular fert dosing.

2 39W T5HO, on for 9 hours each day.

No surface agitation whatsoever.

Side of tank gets morning sun, so sides are covered with green spot algae. Will need to get razors to clean that up and cover the side.

Edited September 25, 2010 by catshanon

[werner]

Yep. That's cyanobacteria. Pick out as much as you can and then try getting some surface movement since it doesn't like well oxygenated water. If it gets worse, or all over the tank, go with the blackouts, etc.

[jvision]

IMO, it is not cyanobacteria. You see that stuff on lakes around here all the time, and I've seen it on tanks lots. It is what I'd call green slime algae. I see it in my high everything tank when I don't dose enough NO3 or when the CO2 is too low. When I was starting the MCI, I saw this stuff and BGA - easily different. When I upped the NO3, I stopped seeing it.

[CursiveDuck]

It doesn't look like Cynobacteria to me. In all my cases of coming across it in the tank world, it's more black. And I've never really seen it float or bubble like that, it likes to coat plants and ornaments and gravel. If it is Cyno, erythromycin kills it pretty quickly, I'm not sure how erythromycin will treat your plants, but it sure as hell kills Cyno lol.

[Vallisneria]

I had BGA in my tank a few months ago.It was like a weird coating sitting lightly on top of the plants/gravel, kind of like a spider web. It was easily removed when you touched it. Its colored varied from black/brown to bright green/teal. I would suggest cleaning out as much as possible, then doing a black out for a couple days. Then once most of its gone up your CO2, KNO3 fertilizing and water flow.

Even if its not actually BGA doing the cleaning, blackout and ferts will help get your tank back on track.

[werner]

Does it stink? <--- my cyano ID test

[catshanon]

I removed this stuff today morning and it was slimy and came off real easily. It didn't stink, but by the looks of it, I am guessing it was BGA. I will add some surface agitation as I noticed that it started when I had switched off my HOB filter.