leaves folding up brown

same with every strain hydro flower stage ebb & gro 1000 hps advanced nutrients hydro corn ppm-1000 ph-5.7 rh-55% room temp-78-80 solution temp-67 4 weeks in and leaves are turning a rust color and curling upwards. this isn't happening in veg. only when I transfer into bud room.

My buddie is having issues with tips curling up ward and turning brown its like tge leaves are folding upward. I leaxhed with ph 6 water and let chill for three days and went back into fert agaon and it seems as if they didnt like it im soooo confuzed