my plants almost done in flowering, everything was fine, next day, all top leaves wher curled up yellow with burnt tips in constantly recirculating hydro..ph was at 6.3,, lowered ph to 5.8 and rasied lights.. was it the lights being to close?? in 1 day??? oh well they are getting flushed now,as they were already finished only had 4 days of flush ahead...think it was heat??