plants need sleep for root growth. mimic the sun, veg i like 16on, 8 off. They really only need 6 strong hours of direct light to receive the amount of photons it can use in 1 day. but need more then 12 to stay in veg mood., a programmable dimmer would be ideal for 5 hours morning at 50% strength, then 6 hours @95% then back down to 50% for 5 hours, then 730nm for 15 minutes, lights out.
I use 24/0 for reveg and clones, 20/4 for autos, and 18/6 for veg. Work indoor clones down slowly to 16/8 when your region will have 16 hours of usable daylight to transition them to outdoor without making them shock into flower and reveg.