Feed times hydro

I use flood trays 4x8...last run i fed as lights came on for about 15 min once a day..im thinking i want to feed twice just shorter time..whats your feed time on and how.many times a day..ty

flood at lights on , mid way, then again at lights out, and once more mid lights out. 15 minutes of flood will raise your RH higher than 5 minutes but if you can handle that its up to you. it really only needs to flood up to the drain and stop if your res is maintained