We just set up our system last weekend using recycled hydroton. I just tested the levels: pH 7.6; NH4 1.5ppm; Nitrite .5 ppm; Nitrate @40ppm. Are we close to ready to add fish? I will do some more research on my end but just thought I'd throw it out there in case someone has a quick word of advice/answer for me. also, I just threw some seeds in (in cotton balls) and a parsley plant from under the snow in the garden.