I am on my 3rd grow and I am having the same problem with all the grows. I got root rot on the first two. I am an expert on cleaning out the reservoir, almost every 3 days, which is too much and using H202. My reservoir is very clean and it only 1 1/4 gallons. It's for two plants. I know its not the nutes or environmental issues. The pc planter I am using is built for what I am doing. Every time I add nutes, I get the brown roots and spots start to appear on the lower leafs. The system came with a small pump and small air stone. It can only be the air supply I think. I am charging my camera at this time. Thanks for the informatiom. Very helpful.