Could this be from wind burn?? I do have a couple fans that are pretty close to my plants and they are on 24/7Are you giving any micronutes? Don't overfeed! Hard to say with HPS light but possibly a zinc deficiency. The cupping shows heat stress like cassinfo has said or possibly over-fertilizing or over-watering them.
Could be.Keep the fans moving air 24/7 but back off a bit.Could this be from wind burn?? I do have a couple fans that are pretty close to my plants and they are on 24/7