when to start the next grow?

I agree with Chevron.. It's better to "cycle out" and clean out your tent and organize up.. Then start over with small plants and plants in flower. Your lights should be raised or higher for your big flower plants and won't be able to give your seedlings adequate light. And besides if you do things right you shouldn't have space in your tent for babies :). That being said I always start new plants outside the tents.. But I have access to a few grow lights.. So if you have an extra grow light kicking around and don't mind putting shit on a shelf or on the floor you can always start up that way.. It's not like small plants need a lot of space... And yea when you start seedlings, you wanna be able to devote some time to them so just make sure you don't get "in over your head". Good luck and happy growing.

Honestly, I would just wait until you harvest. You can start plants on a 12/12 and they go into flower right on week 1. Of course you could the reveg it and have a proper veg period, but who knows how that will affect you in the end? I don't trust it.