Help Needed Leaf edges starting to point up

[dontei]

How long can you keep your hand in between the light and the plant? Depending on your level of ventilation, the plant might be getting burnt by your light.

Cheers,

SMG

I could just hold my hand there all day if i wanted. Its warm but not hot. what height should i have a 600w hps light from the plant. i have seen lots of different heights on the net i saw 50cm n that did not cause it to turn the leaf edges up but i feel thats to far and taking forever to grow.