thanks WH, it souldn't be a ph problem, and I thought a overfert would leave the tips burnt before turning them like that?

he added a gallon of water last night( to weaken the the ferts in the resivor) and adjusted the ph to 6
don't know the ppm, but using the suggested amounts on the flro grow chart and it worked last time , and no burnt tips.

so far no difference between last night and tonight