From what I've heard, water snakes don't usually too great in tubs in snake racks? I'm about to be working with some green water snakes and hopefully breeding them next season. I'm thinking probably a 55 gallon tank with a screen lid to keep the enclosure well ventilated, a heat lamp, a water bowl... What's a good substrate to use for water snakes? Would some type of reptile bark substrate be better than aspen or sani chips?