Hydrogen Peroxide. H2O2

[Proteus]

Originally Posted by Dez

Hydrogen peroxide is commonly used for algae control in ponds. It doesn't harm the fish or plants. I don't know what effect it has in a reef though.

I came up on a farm in the south and we use to drop bales in the dugouts for that exact reason. As they decompose it releases peroxide. Helped control pond scum and winterkill