Quote Originally Posted by jonathanling
hey, i've got 19x18inch space. according to your method, does that mean i need 142500 lumens?
19" x 18" = 342 square inches

342 square inches / one square foot (12" x 12" = 144 square inches) = 2.375 square feet.

2.375 sq.ft. x 5000 Lumens = 11,875 total lumens


One (1) 23w cfl produces 1,550 Lumens (at least the one I was looking at, could vary a little, so adjust accordingly)

11,875 Lumens needed / 1,550 lumens per 23w cfl = 7.66.... so you will need at least 8 x 23w cfl's to reach over 5,000 lumens per square foot.

If you can keep the temps in range, I'd throw in a few more just for good measure :jointsmile: