I just came home from my buddy's house... I was checking out the clones I recently gave to him and the leaves are curling... I'm thinking his ph is off.... His temps are low so im not thinking heat is his issue.. Any advice... ?
Ph issues don't cause leaf curling by themselves. It looks very much like heat stress. Keep in mind that temps often increase the longer the lights are on. Also, both the room air temperature as well as the heat radiated from the bulb need to be considered. You should be able to hold your hand under the lamp at canopy level for any length of time without the top becoming warm.