# Question on BGA and Perioxide?



## LindaC (Nov 7, 2005)

I have just noticed a recent outbreak of Cyanobacteria (BGA) in my 29 gallon tank, it's on the subtrate in the front corner of the tank. Funny thing is, every night I put a powerhead in the tank and place it right in that corner, up at the top of the tank, could it not be effecting that area?

I have antibiotics but would much rather get rid of this without using medication or doing a blackout, if possible. I've read in different posts that spot treating it with peroxide works but I don't quite understand how this is done. Isn't it dangerous for the fish? If your suppose to squirt it on the effected areas with a syringe, do you do this under the water or do you drain the tank down or pull the plants out, etc etc? Can this be done if it's on the subtrate? Most importantly though, will it harm the fish? I've read that you should use full strength too. Can somebody please walk me through exactly how it is done?

Any help or advice is greatly appreciated! I hate to black out my tank. I seriously believe that my problem is due to high nitrates, mine are around 40 and stagnate water on the right side of my tank. My filter is an XP2 and I love it but it doesn't give a whole lot of water motion.


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## trenac (Jul 16, 2004)

Here is a article that will help... Eliminating Algae with H2O2

Although I don't know that it will help with BGA, since it is actually a bacteria rather than an algea.


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## werner (Jul 6, 2006)

H2O2 has worked well on BGA for me in the past. Apparently the bacteria (like many organisms) is sensitive to its metabolic byproducts- in this case, oxygen. This is why getting more oxygenated water flow to stagnant areas sometimes helps.

Manually remove as much of the BGA as possible first & vacuum the gravel. When little bits start growing back, fill a syringe with full strength hydrogen peroxide and squirt directly on the spots. The amount is hard to quantify- not a ton, but enough to "cover" it.

I never had to resort to a blackout, but reducing my photoperiod helped too.

Cyanobacteria at The Skeptical Aquarist


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## LindaC (Nov 7, 2005)

Okay, I'm going to have to give this a try before I do a complete blackout. I only wish I could figure out why I'm getting this stuff. My nitrates have been sort of high, even though I'm dosing ferts EI and doing a 50% water change once a week. I have a little over 2 wpg and a heavy fish load so I'm thinking I better cut down on dosing KNO3. I also tend to be a little heavy handed when feeding my fish.

Only other thing I can think of is the lack of water movement due to my new Rena XP2, although the spray bar moves the water around okay. There are stagnant areas but I've been trying to fix that with a powerhead, it's just so frustrating.


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