Having a little problems with my hydro

I am running into the problem have tried everything cal mag just plain ro I don't understand what happen it started after pruning the roots ph is 6.0 any help would be appreciated

Have you changed your set up at all? I had issues like that when I went to LEDs but it turned out it was just a temperature problem - my GR was sitting at 21C lights on!

An extra heater sorted it out though.