The Hemp Goddess said:
Do not trim any anything (but dead leaves) this far into flowering.
Well some people dont like to cut away at their babies.
Yes trimming your plants CAN stunt growth, shock em, stress em, and all of the above. But if your going from HPS to CFL you can pretty much gaurantee that they will go through stress one in the same. Adding to it doesnt sound smart, but switching the lights is going to cut into yield the most. Why not go ahead and do something that may reverse this, even if it causes a few nanners or makes you wait another 1-2 weeks until harvest, you can pick off the nanners and the bud will still be there for you.
Just make sure you dont go crazy on em, just trim whats dead of course, and maybe a little something extra where the plant is more leaf than anything else. Please make sure when you go to trim that they have just been fed, watered, and they will have plenty of daylight hours left. You shouldnt water 5 hrs before light off as a rule anyway, but if your this far into the grow Im sure you know this.
This helps ease the added shock.
Its like this....
With hps you can just let em grow, its the most convenient(arguable the most economical, matter of opinion mostly) way of doing it that provide what they want.
With CFL you have to change up the whole idea of the grow, this is why CFL is the most controversal way of growing things are done to maximize yield and densify bud sites that growers from the days of HID dont understand because they have never done it personally.
Its kinda like the diff between Vinyl DJing and MIDI/CDJ Djing. They both have their perks and qwerks, both do the same thing, but the style and technique is changed. Vinyl DJs will murder those who speak of CDJs and CDJ users will argue that times have changed and this new equipment allows them to do just what they want and more.
Ultimately its up to you what you do. Keep the HPS and let them finish.
Or go get your CFL lighting setup, get it set up, trim to shoot growth where you want it, get the light super close and see what happens.