Root rot?

Yeah, I meant pH. EC staid at 0.5. I'm lowering the pH as we speak. I used 220ml of h2o2 (12%) for 270L of nutrients. I didnt pick the larvea by hand. Just changed the water with h2o2 in it this time

Never had H202 cause roots to die back and rot. How much did you add per L. Most I have done was 1ml/L to treat damping off. And the 10 ml was applied directly to the stem at the base of the plant. Did you remove all the worms by hand? Could of introduced some bad bacteria while doing it. EC went from 5.5 to 6.9? EC that high would easily kill a plant so I am assuming you meant PH. What do you have your EC/PPM at and did it change at all when you had the PH swing. A swing that much that quickly can do all sorts of strange things. I would say to try to get your PH stable and drop your temp to 18

I have a chiller. So temp is around 20 celsius. Just changed water 2 days ago, EC went from 5.5 to 6.9 in the 2 days. Normally is only increases 0.5 after water change. What do you mean with bomb field? The larvea? That's why I added h2o2. The larvea shrunk and turned blackish. Some are still moving tho...

Houla , t'es racines on une salle mine , contrôle le ph, températures de l'eau. Et t'a nutrition

Oh yeah, pH increased a lot to.