When to sex

Hey all 1st time grower here.

I have 13 seedlings that I started 03-24-07. They are now all approx 3-5 1/2 inches tall. Some of them are already getting there 2nd set of leaves and working on 3rd. I have them on 24hr cycle with low watt fluor grow light.
I know a better light will be needed soon. Probally going to use Cfl's.

I want to know when it would be ok to change to 12/12 to sex and put the the males down.

if you're only using fluoros, you'll want to flower real soon. about 8 inches soon. but if you get a lot of cfls and position the bulbs around and on the side of the plants.....12 inches soon

thanks I was looking at cfl's.
Any idea of how many watts of cfl per plant.
Also what of cool or warm cfl.
I live in a small apartment and I am trying to keep costs down. I also like the stealth with smaller light setups.

warm bulbs for flowering, cool bulbs for vegging. you should get some of both. your lighting needs are directly proportional to the goals you set.

sounds good
thanks for info.