Hey mate, trying to not jack Al's thread, so i thought i would come here. I would start monitering the water temps and dont let them go above 75. H202 will kill anything it comes in contact with, But once the dose is used up and oxygenated, if there is any hint of that bad bacteria in the rez it will start forming again.
If you got some time on your hands and a bit of extra cash make some Heisenburg tea. Pm the hydro mod Hellraizer30. very helpfull dude and is/was a full time tea brewer.