If you are running Aero then I would say 24/7. Since Areo's closest cousin would be DWC and we all know it bad when the air pump dies
tinytoon Reviewed by tinytoon on . Water Exchange When doing water exchange how do you keep the plants happy? Should some excess water be left in the AeroFLo 36 growing chambers? How long can plants go without any water on their roots? What is the best method for keeping plants happy during water exchange? Rating: 5