if they're actually drying out between waterings, then that's good enough. if it only takes them two days , then water every two days, but if 5 gallon pots are drying out in two days, i'll bet your RH is very low. i try to keep my flower room in the 40% rh area...thats plenty low enough for pm and mold to not be a problem, but not so low that it causes the plants to over transpire, or get leaf edge curl
having the rh too low can cause leaves to burn. they have to transpire in low rh, and all they have to transpire is what you're feeding them, so leaves can build up toxic amounts of salts in low rh and burn themselves from the inside out