I have 2 auto strains in week 3-4 they are becomin...

you will get stretch because of not enough lumens take light higher it will stretch more heat is not a factor its the light spectrum coming off the lamp the plant grows from

Hey, so when i use my cfls i keep them pretty close usually the 8-10 cm like mentioned. A handy tool i came across are lightbulb splitters so you can use multiple bulbs on the same lamp. It's helped me to stagger lights throughout the canopy. I'd keep the same distance...any further away and the plant will want to stretch more Good luck with grow.✌️

Like what was already mentioned, they should be fine at that distance, my plants didn't burn until they were literally touching my CFL. You don't want too much distance with that type of lighting to prevent stretching. Your leaves will start to curl if they're not happy. Also, a friend of mine made a pretty cool reflector out of a 2 foot length of 4" duct that I could see potentially beneficial for a setup like you have to help direct all the light downward.

You should be ok, as a test hold your hand just above the plant. It's to hot you should hang your light higher