Uncle Ben
Well-Known Member
You can put a bare 600watt that close, even 9-6 inches. With a cool tube 4-6 inches away is right.
Get a light meter. At 4-6" away with the usual conventional hood that is more light than the sun and will bleach (destroy) those top leaves as yellow as a canary. See my sig. A bare bulb less but the bottom line is, you can give a plant too much light.
UB