Super Lemon Haze curling under... help! (PICS)

Hi there.. so my SLH is about a week and2 days old.. and the leaves are curling under. The only thing I can think of is its got something to do with the water.. 2 days ago I started using distilled water, but before then it was tap water. I haven't given them too much.. because I water when the soil gets dry an inch down, and I give little servings more often rather than a big one once every day or two. Not yet using nutes.. so that cant be it either.. my light is a 400w hps about 18 inches from the top.. could it be heat? The light is on 23 hours a day... and tempurature is usually around 30c. I need some help before my baby dies... anyone...? anything??

Heres some pics.

too much water

http://www.marijuana-seeds.net/Thanks-ThankYou.htm

lol my partner posted the same post as me.. overwater and too small of a pot greenthumb !