bad root root?

not sure how bad this is i flushed w/ ph water and washed all slime of. ran new water w/ h202 what else shld i do to keep at bay i use organic so no neuts till i flush h202 again gonna get some hygrozem unless there is somethin better out there

hygrozyme will sort you out in 5 days, but what can be discouraging is when it takes effect, the water gets nasty, this is ok cus that is the dead roots falling off into the water, for great results change the rez water everyday and add fresh water with hygrozyme for 5 days, by then you should have cleaner water and major new root growth, after that you need to monitor your water temps, above 75F is wreck your setup

I'm a pretty new grower so take what I say with a grain of salt...
It doesn't look like root rot to me. Are the roots brown and brittle? If not, and there's just a dark slime, my guess is it's algae growth. I have a similar problem, check out my thread:
https://www.rollitup.org/hydroponics-aeroponics/187179-algae-problem-dwc.html

It looks like your res isn't lightproof. Also, did this problem just suddenly appear? If so, what did you do in the few days before it appeared? Thanks.