Hey Shake,

Nah, I don't think the H2O2 is the issue. Believe me, I did a lot of research and also talked to the AN tech support person.. For cure/prevention of root rot, 1 tbsp + 1 tsp per gal (1 tsp per quart). The other thing it does is help oxygenate the water (the extra O molecule is the only difference from water) and it also breaks down within a few days. The only bad thing about using H2O2 is if you have any beneficial microbes, it'll kill them along with the bad ones.

Farmer Rich