Hey Danny, i saw this coating over at my local hardware store you can coat cinder blocks with to make them water proof they even had this little display with a fountain it looked like it works good. I was thinking of using rhino lining also for my own set up but i have a friend who housed a water monitor and used that rubber lining for his tank and his monitor scratched and ripped some of it which created small leaks, although i don\'t think crocs have as long and sharp nails to do that.