You need to move to hydro section,you will get more help. Maybe too much heat in attic. Or needs cal-mag plus or could be overwatering, I see rockwool cubes . They are easy to overwater if your timer is not set right. Pic's are great help. Tell us about your setup. Temp's in attic and temp in rez. What's your PH and what nutes are you using ? What kind of water are you using ? It make a big difference. What kind of meters do you have