Time for 12 hour cycle? and other advice wanted

You can link the diary to the question if you ask it from within it without the need to waste your text allowance on its URL. Yes you could switch to 12/12 and prob should. that's a long veg cycle. The plants will stretch a bit and should kick into full flower in 2 weeks from switch. Good to note they still need N in bloom and a good amount in the stretching period, so don't flip to bloom nutrients till after the stretch is done.