Hello. I have been having this problem ever since I started growing in my DWC system. Every time I do a water change, my roots seem to exhibit root rot. The water temps are fine PH is 6.5, I have 1 water stone per plant (2 of them) and I am using a 10 gallon DWC. It seems to go away after a couple days but still stuns my plants growth and destroys most of its roots. I even bought aqua shield to see if it would help this time around. I want to know if anyone has a solution or a reason that this would happen. Thank you! \t\t\t\t\t\t
I kinda had the same problem...couldn't cure it but this is what I did...emptied my 5 gallon bucket, ran a couple gallons of Peroxide mix through the hydroton pellets, provided new r/o water with K-N-L and superthrive...waited a couple days...didnt see any changes, roots were just dead. I decided to just start a new clone instead of dealing with long term problems. I believe the initial problem was that I tried to salvage a clone that had dead root at the bottom of the rockwool cube. Its important to make sure the clone has nice well developed white roots. I'm looking into some shit called H2O2 as a preventive measure...so far it seems to just be another form of peroxide.
Its might be because your ph is off hydro ph is typically 5.5-6.1 where 5.8 is optimal and for soil 6.3-6.8
adjust your pH; as bdm80 said, its off. Pics please? If roots are brown, it could be because nutes are staining them (ph 6.5 = nutes not readily available to the plant, stays in solution) Or it could be some sort of pathogen; run some H2O2 once if the roots are slimy