I have 4" pvc connectors as water bowl holders and plastic Fabricare 8oz water dishes for my adult BP's. My tubs are 6" high and the pvc sits on top of my substrate (newspaper). My BP's have less than 2" to get into the water bowl. Is that about the same amount of room for your BP's? Since they are not going to be soaking, I don't see why this wouldn't be ok, but I just wanted to see what you experienced breeders do.