well it all depends on what kinda grow material you use, just check your roots and make sure they get oxygen, they want to look fresh and white...ish, im not using rockwool next time, becuase it holds alot of water and when they get big im getting like very litte root rot, dont want that so. Strait up hydroton in the netptos. in rock wool u do want to use a normal setting like 15-30min watering 2wice a day.