Is it the light or the heat?

[Mr.RiverBed]

I am growing two kinds of plants. A chronic and a purple kUsH. So far I have them both under a 65 watt plant light. Time and time again, day after day, I rotate them so that hopefully they each get the same amount of light. I had a watering problem aswell but I managed to fix that (R.I.P. First Grow) I am guilty of drowing it, transplanting it unsucessfully, and burning it. Typical first time growing mistakes I know but it still hurts.
Thankfully I learned that plants need a good supply of water, but to not over water them. The possibilities of a plant surviving a dried up environment for a day or two are greater than surving them underwater. Plants need a good soil mix. SO at the risk of exposing myself as a true beginer, my question is: What does the plant need most, the light of the bulb or the heat the light produces?

[motorheed]

the light mate,but heat helps too,so both ,lol..............but if i had the choice of good light & no heat or vice versa,then it'll be the light mate(can rig up a heat source).......that answers your question ,but you do need heat so dont think you can grow with a light only in a cold room as wont get you too far.........

peace.................