tips down

hi all can someone tell me whats going on with my plants/ i have 6 plants; 2 gdp , 2 grapefruit kush, 2 grapefruit diesel growing in 5gal net baskets in 5 gal buckets in a recirculating drip dwc system with a 40 gal tank .flowering stage 2 1/2 weeks into 12/12 . 1000 watt hps 18-24 inches...