burnt top

[florida boy 3]

hi all, i have a inside grow. woke up this morning and one of my plants was burnt from my light. i have a 400 watt, my plants are about 3 wks old. my question is how far away should i keep my light from the top of my plants? thanks for any replies.

[latewood]

try 16 " for 400w...if it burns move it farther away 6", try to keep it as close as possible w/out burning the tips...

[fhydro]

And try a fan also ...
Fhydro