What i do is frame the bottom so this would be the base that your cage sits on and raises your pool off the floor about three feet.And for your pool, frame a box with your existing cage floor and use plywood to case it in. And always make sure you frame the inside and not the out side of the box frame because you don't want it to burst out lol.Then cut the floor of the cage any shape you would like for your pool.Then take some expanding foam and foam all the way around your framed box under your cage floor till you cover all the sides of the pool box .Then use a nife to shape the foam with your cut out.Then cut out a hole for a drain cap like you see in your kitchen sink.It is now time to finnish your floor with heat mats with the pond liner over top and covering the hole floor and the pool.Then frame your walls on top of your floor so the pond liner is tight and even.Then feel for your pool hole and make a small x so your drain cap fits tight and use non toxic silicone or glue to secure the the cap.This way your snake can take a bath in his own bathroom.You can now drain your pool easy by adding a tub underneath for draining.The walls are vynal and can cover a 12x12 sqft cage.I hope this helps