cupped under leaves outta flowers

Hello fellow puffmasters.This is my first grow in a dwc sterilite tub with drip system. I vegged under a 400 MH and am currently 3 weeks into flower under a 400 HPS. Temps are at 80-90 lights on and 75-80 lights off. Ph is at 5.2-5.6and am using tap water. TDS is at 412 because I overferted a few weeks ago and had to flush. After flush plants looked sweet and started to stretch like crazy without bushmaster. My recent problem is top smaller leaves outta flowers are curling under. Looks like a upside down canoe and tips go straight down. Wondering if anyone can help and how serious this prob is? Using flora nova bloom and floralicious and koolbloom for nutes atm. Res temps around 70Any help would be greatly appreciated and just wanted to say wouldnt have got this far without you guys. Thanks and rock on:)

ive had that problem also with the leaves curling i havent been able to figure it out, but i would say ur temps are too high, i try to keep it between 75-80