light cycle question

This is the second day after i put the germinated seeds in the soil (8 solo cups). I started out the lighting (2CFL and 4 Florescent) 20 hours on (12pm on 8am off) and I am reading a lot of people saying 18on 6 off which I will more likely switch too. I am planing on switching to HPS in 2 weeks. I also have white poly in the closet.

My question: Will it harm the sprouting process if I change the light cycle or should I stay with what I am at? and If so when is the best to change it?

You can go ahead and change the light cycle. It won't harm the plants. It isn't advisable to keep chopping and changing light cycles, though, but a couple times won't hurt.

I would change it after the lights go out by adding another 2 hours of darkness before the lights go back on again.