18/6 I suggest especially under high light. So 12/12 flower means about 1/3 less but always go by plants.
With co2 some adjustments need to be made as increased co2 actually reduces transpiration rates. So you may find a bit higher ppm and lower humidity make up for that.
I'd love some insight on what I should do in my new setup, sealed LED veg room with co2. I have rooted clones in solo cups right now and about to transplant into 2gal(final containers) of pure coco. My temps are from 73/79, night/day. I have my co2 set to 800ppm, but it ranges from 700-900ppm. Par levels were high at 600ppm until I got my par meter and now have it averaging around 450par.
My humidity at canopy level ranges from 75-85% and I feel this might be where the issue lies.
First thing I noticed is the plants are not drinking as much as they should. I keep my plans in solo cups and usually after 2 good dry-backs over a 4 day period I would be feeding daily and solo cups would be light the following day. Now in the new room I get to this point at about day 10, typically would happen by day 4.
Tonight I'm transplanting into 2gal container that have (2)0.5gph emitters per pot and I was really hoping to be able to feed these plants multiple times daily. I'm concerned I will have a similar watering schedule to how the plants were in solo cups which defeats the purpose of the automated drip system.
My plants look super healthy... considering sealed, LED and Co2 in veg is all new to me, I'm very pleased with how nice the plants look. Root development in the solo cups is on point too, no complaints. I'm just concerned they are drinking slowly.
Any insight to all of the above is much appreciated... mainly want to know in this type of setup where your co2 levels, par #'s would be and if I should try and lower the humidity or if it aint broke don't fix it.