davemonkey

I've squirted H2O2 directly (via syringe) onto cyanobacteria. It bubbled profusly and vanished in 24 hrs.

playthecello

I'd say 2ml/gal dosed two consecutive days killed 90% of my BGA, along with 90% of my anacharis, hornwort and milfoil. Another day probably would have taken care of it entirely, but when I saw my plants disintegrating I panicked and stopped treatment. The plants are growing once again, but the BGA is slowly coming back too. I removed the sensitive plants last night and dosed again, and ordered some Marycin just in case. I'm tired of paying for the stupid algae-causing mistakes I made a month and a half ago and I want this stuff dead.

mudboots

I used better than 4ml/gal one day after using 3.??ml/gal and killed 99% of the snail population. The fish seem fine, except a couple zebra danios have nipped-looking fins, though they nip at each other regularly, so this may not have anything to do with it.

I noticed pretty similar results on some of my mosses. While some pockets of them were untouched, others were nearly obliterated (using the 3.whatever and 4ml concentrations back to back).

However, I've just put in a significant order to InvertzFactory and hopefully can rely on critters to do my algae work from now on. Even though I did not many plants (yes, some did in fact perish), I lost 30-50% of my leaves (depending on species) and 100% of the leaves on my 2 red lotus. They're coming back as we speak, and now I have another baby coming up next to one of the mama plants.

H2O2 is awesome as a treatment, but overdoing it can cause more harm than good IMEO (E becaue I figure after blasting peroxide into the tank in such quantities I've killed enough plants to have formed an educated opinion). Buy some otos and other algae lovers; they're relatively cheap and make great tank additions.

P.S. - After all of this, the green water STILL did not vanish. If the conditions exist to support algae beyond the plants' capabilities, there really is no quick "cure" to your woes. Be patient, find the problem, and be patient some more...

wi_blue

I had green water earlier this year. I did a 3 day black out and when I saw that the water was still cloudy I put 2 willow tree cuttings (long enough to get burried in the substrate and protrude from the tank) into the tank. I was lucky enough to have cutting that already been rooted. I left them in till the water cleared.

The old man

I am trying the H2O2 treatment today in one tank. This tank has some string algae, BBA and a small clumb of Brush Algae.
The animals are corys, loaches, rummy nosed tetras, black line gobies, ottos, swordtails and baby mollies, one bristlenosed pleco and a lot of red shrimp. I started with one ml per gallon doses using a shringe. Will spot treat the plant leaves and driftwood each day for a week and see if I get any results. Will change about 40% water weekly. The tank gets about 5 watts per gallon of lighting 10 hrs a day and is running an Eheim canister filter. Algae did bubble a bit and some turned white today with the first treatment. No plants, fish or shrimp was effected yet. Will update this next Saturday.

The old man

Spent 5 hours with Microsoft upgrading to Windows 7 yesterday so I'm a day late with update.
No fish, plants or shrimp have been effected by the dosing which I increased to 2 ml after three days. Did water change today. I did cut back my lighting to about 2 watts per gallon during the treatment. Results so far: Most all the BBA has turned either red or white and the black line gobies and now the otos have been working hard on it. The string algae is almost all gone and the brush algae turned white and separated from the driftwood and I just took it out. Still got more BBA to go, but it does seem to be decreasing now. Will report back in another week. Oh yes, the blackline gobies in another tank are really working and reducing the BBA algae. This tank is not getting H2O2, but Excel overdosed instead.