Thanks Blue. I put 20% less in the resivoir as directed on the bottle. Also used the main nutes as I was instructed to do so by the Hydro store. PPM is reading 600, should be okay I hope.

Talked to my friend who is taking care of them, and he said some slight slight curling on a few plants on the leaves (this has been a problem for over a week now) Doesn't seem to be spreading, said it doesn't look serious.

He also mentioned that the room is getting quite cold when the lights are off, is there any type of stress that the plant goes through if the difference between lights on temp is different than lights off temps?