A foot and a half already ?
Unless you want to have huge trees you should out them to flower right now. You have to figue they could stretch over 3 times their size in flower.
Cap K
Tatan aint shitin ya bro. Mine went from 6" and 8" to over 25" in 5 weeks. Yours could be 5' tall.
You could super crop or lst. I would top it like I said before, veg a week then go 12/12 and throw as much light on it as you can. It seems from the treads I have read most of the cfl grow tall. Like hps, cfl is missing that blue spectrum.
I seen a comparison on veg between hps and mh. The hps stretched more and was not as bushy. The mh stayed shorter, tighter nodes and bushier.
I veged with a 4' T5 HO 8 bulb, 5 blue and 3 red. Kept it 1" from the plants. At 6" - 8" they had like 8 nodes and the stem was as big a a lighter.
I tried Uncle Bens topping method and it worked great. The only thing was it was a male, they only one I tried.