Do you need to change you lighting when going from...

All you have to do is give it less than 12 hours of light per day to start flowering.

Don't expect to get a decent yield with a cfl bulb. They are only good for the first month of growth. You can get a good led for $100

Hi, a 125w CFL wouldn't be enough light I wouldn't think, once the plant get to a certain stage it will require more light. Also, most CFL's are either red or blue spectrum. Do you know if yours covers both? As you want light from the red spectrum for your flowering stage, blue is for veg. Something like a 400w CFL maybe more suitable but I've no experience using CFL's in flowering. I have used blue spectrum CFL's for veg a few time but found you need to get them pretty close other wise growth is slow. I would then switch to a HID for flowering. On my last grow I just used the CFL's for the first week or so then Vegged on the HID for a few weeks before switching the light cycle to flower. Hope this helps.