holland secret abc follow directions on bottle, cal mag 1 tsp per gallon, hygrozyme... aeroflo2 36 for me rocking a 1700+ ppm mid flower not a sign of burn, always use a chiller imo, just part of the system along with an ro machine another key part to sucess doing any hydro gro. chiller and ro, dont be satisfied with 70 degree res temps, they will do better with 65 low as 61, more do. after removing the air stones im locked at 5.9 ph, was having rising ph issue until got stones out of the mix