If in need of keeping them short, why did you chose a sativa dominate strain?
If you are really short on vertical space, I'd FIM the crap out of 'em, and put them under 12/12 a little early. You may still have to tye-down rogue branches in flower though...depending on the strain's propensity to stretch.
Fimming will cause some injury that delays growth, which will add a couple of weeks to the harvest date.

I have plenty of headroom and I prefer not to FIM, but it can be an effective tool if used right, for the right reasons.
Rusty Trichome Reviewed by Rusty Trichome on . FIN cut advice Plants are in their 5th week. Did 1st FIN cut about 10 days ago and plants have responded very well. Question is, can/should I continue this method? Our goal is to produce short, bushy plants that will better accommodate our grow space. Space is very well lighted from above as well as from the sides. Plants are from seeds that I was told are a sativa "White Shark/Great White" strain. Rating: 5