Start Vegitative State in 12/12 then Increase to 16/8? Possible?

I wanted to know if I could start a seedling in 12/12 conditions for about 3 weeks and then switch to a 16/8 lighting schedule.

I have read there is not much problem in doing so. Increased time in the vegetative state doesn't have a big negative effect. However, decreasing time with show some symptoms

Any input?

It would eliminate the need for a Veg/flower room.
You can simply start Veg four weeks into flowering. Once you harvest, you can revert to 16/8. then back down to 12/12. repeat.

Might work, might not. I had one day loss of power due to Irene, and my week and a half old clones started to bud. I understand why you want to do it, and it isn't a bad idea. If the plants are somewhat portable you might consider putting them under some cheap flourescents for a few hours when you have to turn off the bud room.

I was growing 12/12 from seed and they were just starting to show hairs. My pumps for my wilma's died and they never got water for 3 days and nearly died. I gave them 2 weeks of 18/6 so they would recover. Ended up with loads of bud sites