Question about drain and fill frequency. I have my...

It actually depends on a few factors, like the media you are using. A fast draining media will require more frequent floods; on the other side a media that retains more water, will require less frequent floodings. Also, warmer temperatures will require more frequent waterings. What you must keep in mind is that the roots must never dry out and let your plants health be your guide From your pictures you are using hydroton, right? Try flooding for 15 min every 2 hours. You will have to dial your system from there; if you notice it is thirsty, flood more often (but keep the 15 min flood time), over watered? flood every 3 hours.