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Algae ID request: Black GSA???

2526 Views 15 Replies 5 Participants Last post by  longhornxtreme
HI all,

I've been fighting this dark algae for quite a while. I've posted a link to an outside gallery. Take a look at the pictures and let me know what you think. I realize that most of it is GSA - which I can't seem to shake. But look at the black stuff on the Valisneria... I get that on my Crypts too, however, I had just recently pruned a bunch of them so I didn't have any good examples to take pictures of... Is something just happening to the GSA that makes it turn black? The reason why I think no, is because I still get the black junk even if the GSA is under control. Typically, GSA isn't a big problem, but I've been mucking about for the last 2 months really trying to beat this black stuff... My PO4 must be a little low.

I guess what I don't understand is why some parts of the tank are pristine, and other parts of the tank look awful. Is it because the otos take care of the better looking parts, but avoid the high flow areas or areas where the angel might be aggressive?
The algae seems to occur in the higher flow areas of the tank and not so much in the low flow areas of the tank. Does that make sense at all to any of you?

Sorry for the lack of a pleasing aquascape... I'm still new at this, and school has been eating up all my time lately.

Tank specs:
  • EI dosing using homemade solution w/ dry ferts - I add Mg to the macros but not Ca, water is pretty hard around here
  • CSM+B for micros (I do have a full bottle of Fluorish, and Fluorish Iron sitting around if that would help)
  • regular dose of excel every other day
  • 29G
  • Eco-complete
  • Eheim classic canister
  • 2x36 w T5 Normal output coralife 30'' fixtures - only running 1 currently until I get this black algae figured out; I've played with photo period but to no avail; it is at 8.5 hours currently. A new canopy plus 2 24" T5HO giesemann's have a piggy bank that is about halfway there budget wise.
  • pressurized CO2 - bubbles are fed into intake on eheim - 1 bps, seems if I go any higher it really stresses the fish
  • I have a powerhead in the tank to occasionally blow O2 into the tank to clear up the surface crud.
  • The airstone you see used to be on a timer to clear up the surface crud, I really only keep it there in case of a CO2 emergency...
  • 7 H. Rasboras
  • 1 Koi Angel
  • 5 Green Cories
  • 2 Otos
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Hi longhornxtreme,

In some of the pictures it looks like regular GSA to me. I think the dark "clumpy" algae in a couple of the pictures it possibly a different algae. You might try more Potassium for the GSA and dry dosing with Flourish Excel, per the "sticky" in this forum, for the other algae.
I know that most of it is GSA; any ideas on what the dark clumpy algae is?
Sorry longhornxtreme, I have not seen it before. It doesn't look like the black brush algae, I have had that in the past, and it doesn't look like blue green algae. Maybe it's just algae?!!! If you haven't tried the Excel treatment you might consider it, but your Vals will probably suffer. Sorry, wish I could be of more help.
I appreciate your time!

I've tried excel overdoses... funny thing is that my Vals seem to do just fine.

In a month or so, all those plants are going to get replaced after I build my new plumbing parts.
The black spots may be small colonies of black beard algae that your otos chew down, but do not remove. Try releasing some hydrogen peroxide on them. If they turn pink, then it is definitely bba. I have ramshorn snails in my tanks, and they take care of green spot algae.
I have also seen what looks like black GSA from time to time in my tanks. It seems to show up particularly on old abubias leaves. I also don't know what it is. I don't think mine is BBA because I don't have anything in the tank that would chew it down. Next time I see it, I'll tank it to my algae professor so he can ID it.
I've got a syringe; I'll try some H2O2 today or tomorrow. Good idea to try and rule out BBA!

I've never used H2O2 in a tank; are there any guidelines as to dosage amount / concentration of the H2O2?

Zapins: Is your signature quote from a game called "Cannon Fodder"?
I've got a syringe; I'll try some H2O2 today or tomorrow. Good idea to try and rule out BBA!

I've never used H2O2 in a tank; are there any guidelines as to dosage amount / concentration of the H2O2?
I have never used the stuff, myself, but I recall seeing quite a lot of discussion on the algae forum about local dosing of algae and observations that black beard (or brush) algae turns pink. Somebody else who has done this will have to tell you about the strength to use. I am sure that somebody will!
THanks... I'll do some forum searching later on today!
Nope, its not from there :)

H2O2 will be broken down very quickly in your tank (a few seconds, maybe a minute). So it doesn't really matter what the concentration is. Try a 1:1 ratio in case it burns the plants that it is attached to. If the plants are frilly or delicate dilute it further and keep raising the concentration until it dies over a few days.
It's interesting that you have bba popping up in high flow areas, you're not the only one to say this. I'm having the same issue right now, even with crazy amounts of CO2. That's one algae I'd like to figure out. Common knowledge states low CO2 to light is the culprit, and you'd think the high flow areas would be supersaturated enough (as long as diffusion is close to 100%). Perhaps there's more going on there, like transfer time or something keeping the molecules from being usable right away, some kind of chemistry I'll never quite grasp.
The only reason that I haven't called it BBA yet is that it has NEVER gotten 'fluffy.' Does that make sense? I've had BBA no question about it in an older tank, and I've helped a friend clean up a 55, and spot excel treat it. But this stuff is dark black, and eventually gets on the glass as well.

Additionally, I wonder if there's something in the tap water around here that would combine with something in the tank to give the black tint? I really suspect that some of it starts out as GSA and then turns black... The glass gets a black agae that has to be scraped off with an old credit card - pretty tough stuff.

I'm going to pick up a bottle of H2O2 tomorrow and see what happens...
I know exactly what you mean, I went through the same thought process on this stuff. You mean the black coating that covers the tops of vals, and likes to cover anubias leaves. I still think there's a chance it could be something different, but from all the searching I've done the consensus is BBA. Incidentally I have seen tufts come from vals in the same area as the black coated algae, but I've had it cover rocks and never show tufts.

There were times in my own bad GSA days, that so much GSA would accumulate and cover anubias etc, then die and turn from brown to black. So, for a while I was convinced the black coating was the same deal, but I'm convinced it's not GSA now, since I haven't seen any of that in about 2 yrs. But I have lots of black stuff, along with black tufts, especially on vals, crazy CO2, lowered light and photoperiod, but still the high flow spots are the worst.
Gosh I was absent minded; I went all the way to the drugstore to buy bar soap and H2O2... and guess what I didn't buy.... H2O2!?!??!?!??!?! :mad::mad::mad::mad:

Stupid paper for school has got me all mixed up. :rolleyes:
Well I hit some of the spots with H2O2. I'm taking it slow because I really don't want to risk my fish at all. So far, it has bubbled, but no pink just yet.

However, I think I figured out 'why' the high-flow regions of the tank have BBA on them: the spray bar and output tubing looks like it has a bunch on the interior of the tubing. So shortly I'm going to soak the whole mess in a H2O2 solution. I.e., the spraybar is just flinging BBA around the tank, and it settles on the plants.

I'll post an update at some point.
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