Trying Something New

I'm trying something new... using rock wool slabs instead of the rock wool block on top of the rock wool block method. I have it set up that the plant is in a rock wool cube and 2 cubes per slab. I water using the woodpecker drip stake... one in each plant cube and one in the slab. This is obviously indoor growing and I'm using 4 1,000 watt lights for 40 plants and they are in the veg stage. What my issue is... what would be a good watering schedule as far as how many times in a day and how long the water cycle should take place????? Another question is should they get the same amount of watering during their 6 off time as their 18 hour on time???

Thanks guys for any help you can give me!