I using tap water, same as I have been using in my E&F systems for over a year now. I get my yearly water report but dont have a clue wtf it says since there isnt a ppm are anything of the sort in it. added 2 capfuls of H2O2 last night to the 3 gal of water in res and this morning the roots look ALOT better. Doesnt appear to be slimey and brown color is disapating. When I changed water on Sunday I wiped out the bucket and rinsed best I could and whaite rag I used for wiping did remove a brown film from sides of bucket and tops of stones. I starting to think maybe H2O2 is gonna be a constant add to the mix. Also added 2 24" flouro's to the lighting setup.