Algae ID, cure suggestions

[alexv]

My tanks are plagued by this weird algae and I'm trying to figure it out what it is and how to get rid of it.

It's a darkish blue-red algae that covers surfaces as if with a blanket. Looks like cyanobacteria in this respect but unlike cyanobacteria, seems to be doing just fine in higher nitrate levels.

This thing grows rapidly and is sensitive to light. I tried total blackout for 4 days and it cleared the tank, just for the algae to come back a week or so later. What I want to know what else I can do to get rid of it. I tried to doze more KNO3. I tried less, increased light, decreased light. I know that it will totally die without light but I can't keep them off all the time. So, there must be something in my water that makes it come back all the time.

This tank is a 55g with CO2 injection and I'm dozing fertilizers per EI method.

Oh, one more thing, this algae is not really attached firmly to the surface. It can easily be removed by hand or even sometimes vacuumed off the leaves/substrate. See the attached pic for how it looks like.

I really need help getting rid of it...

[Dekker500]

It really does sound like cyanobacteria...

Starve the suckers.

• Feed your fish the minimum required - all they can finish in a minute or two, and no more!
• Reduce your phosphate levels - Setup regular water changes to reduce/control your tank levels.
• CLEAN your tank - vacuum, and use your fingers or toothbrush to loosen the stuff that is on your tank. Repeat whenever you see it coming back
• If you don't have live plants, kill your lights for a couple weeks. This is rather drastic, and though it kills what is there, doesn't solve the conditions that brought it on in the first place - excess phosphates in your water.

If your house/well water is high in phosphates, you can use phosphate-removing media in your filter.

Hope this helped!

I've had it breakout occasionally when I got lazy (almost never do water changes in my planted tanks...) but every few months it becomes necessary... Control its food source to control the bacteria!

[HappyGuppy]

Have you tried H2O2 on it yet?  I'd bet a dollar that done properly it would solve your problem.  If I'm wrong you'll win the cost of the treatment back... which is about $1.

[alexv]

Ok, I may have some high(er) levels of phosphates. Is that proven (or well-known) that higher phosphate levels promote cyanobacteria growth? Just curious.

[Dekker500]

Ok, I may have some high(er) levels of phosphates. Is that proven (or well-known) that higher phosphate levels promote cyanobacteria growth? Just curious.

Here is one source quoting phosphates and cyanobacteria.

And here is another.

Let us know in a few weeks if your problem is under control... It'd be nice to have it confirmed!

[alexv]

Here is one source quoting phosphates and cyanobacteria.

And here is another.

Let us know in a few weeks if your problem is under control... It'd be nice to have it confirmed!

Ok, thanks. I will see if controlling PO4 more closely makes any difference. The only issue with the above articles is that they seem to be related to saltwater. I realize that cyanobacteria lives everywhere but their suggestions of keeping nitrate and phosphate low are hardly applicable to fully planted freshwater systems. Here is this article that mentions that higher phosphate levels inhibited growth of some strains of cyanobacteria...

Anyway, I will try to keep phosphates really low and see what effects it has on the tank...

[magnosis]

Have you tried H2O2 on it yet?  I'd bet a dollar that done properly it would solve your problem.  If I'm wrong you'll win the cost of the treatment back... which is about $1.

I had great success getting rid of cyanos with H2O2 applied locally with a syringe, using 2-5 ml per gallon of water (max), 3 treatments over a week and it was all gone.

[Dekker500]

This algae got me going again... and so I did some more research. If you're into the biology, http://www.who.int/water_sanitation_health/bathing/srwe1-chap8.pdf will give you more information than you probably want, but section 8.8 and 8.8.2 are good reads... Looks like excess nitrogen can also cause a bloom... and you mentioned dosing KN03, but you also mentioned you backed off. Perhaps backing off on that nutrient for a while, combined with a few regular water changes (and some cleanup) will help.

[alexv]

Thanks, I'll give it a more careful read. I'm doing another week-long blackout in my tanks. After that I'll do some careful cleaning/water changes and will try to watch ferts more closely and see if I can get it under control.

[Toss]

BGA is a sign that you need to clean your tank, that's all. A deep gravel vac, rinse your filter and water change. They will go away by itself.

[alexv]

BGA is a sign that you need to clean your tank, that's all. A deep gravel vac, rinse your filter and water change. They will go away by itself.

Well, I will do that. However my tank is on a constant water change drip system, changing about 70% weekly. And I clean filter media one every week or two.

[Toss]

Drip system is great and less time consuming but remember that 70% is not actually 70% if you look at it carefully. Cleaning the filter media every week or two is also work against you. How about gravel vac?

[alexv]

Drip system is great and less time consuming but remember that 70% is not actually 70% if you look at it carefully. Cleaning the filter media every week or two is also work against you. How about gravel vac?

Yes I realize that. And that's why 70% continuous will be more like 50% if done just once a week. Still a pretty decent water change schedule I think. And why cleaning filter media will work against me? I basically have a sump in the basement with filter sponges in. I clean them as soon as they get clogged to the point that water starts overflowing from the filter compartment.

And yes, I do some surface gravel cleaning. I don't do deep cleaning though.

Oh, and the substrate is heated so there should be some water circulation through it to prevent stagnation and the gravel is coarse sand, so it does not compact too much...

[Darth]

i'd go with h202 although it will kill benficial bacteria as well as the bad, just take out your filter sponges and keep them in a bucket of tank water while you are treating, or you can use eurithomycin again same thing applies, and don't run carbon while doing this, I had a bad outbreak of cyano in my reef, and used maracyn as my last result cleared it in 2 days again will kill good bacteria as well, but in an established tank this shouldn't be too much of an issue

[sas]

BGA is a sign that you need to clean your tank, that's all. A deep gravel vac, rinse your filter and water change. They will go away by itself.

This is the best advice to follow in my opinion.
Worked for me when I had an outbreak.
Watch your tank temps also, I found fluctuations into the high
levels didn't help.

[alexv]

Ok, just wanted to post some updates. I did thorough cleaning of the tank, multiple water changes, gravel vac, filter clean, all kind of things for a couple weeks. The algae was gone for a couple days just to return stronger than ever. It covered everything in a thick blanket. Both tanks were completely covered with the slimy carpet. Every leaf, every piece of wood and even the glass.

So I've had it with this and bought some erythromycin. I treated both tanks at 1/2 recommended doze for about a week (dozed every second day). After a couple days, a lot of cyano started to die and peel off. That's when I started to vacuuming the gavel like mad. There were so much stuff accumulating on the gravel.

Well, after this all was done, the tanks are completely clean. They have been like that for about 3 weeks now and so far I have not seen a trace of the cyanobacteria. I do hope it will stay like that...

Once the cyano was gone, the plans started to grow again. They were completely stunted and most of the plants were on the verge of dying. Now they are back to life and seem to be doing fine.

Anyway, here is how my 220 gal looks like today (see attachment)

[cory]

Used H202 on mine and it worked. Within 2 weeks it was Algae free!:)