How much h202

I have not had this issue before. I used bennies the first run. Temps are fine ph and ppm are stable. Did I hit them too hard too young? Running around 500ppm GH trio, bennies and floralicous. I’ve completely changed res. I’ve washed the roots down. Brown is normal with the floralicous but this is rot setting in.

I have 3% h202. It’s going to kill the bennies. And that’s fine. I’ll sterilize and redo.

My roots are getting the sludge. How much peroxide. 30ml/L