leaves turning yellow , could you please tell me what it is , i feed a 4th of the strength what on the dutch master bottle i give A+B 1 ml, per 1 liter, Silica 0.5 ml , Zone 0,5 ml , Max grow 1 ml / per 1 liter PH is at 6,1 , the are in root it plugs who got placed in rockwool cubes