Are you talking a whole tray to catch and drain excess misting water or just to catch dripper water? I never mist my cage to the level of needing a drain system, it gets damp but drys before the next timed misting. To catch dripper water I use a tupperware container with a screen top, and it has a drain tube that leads to an empty 1 gallon milk container. I actually reuse this water a couple times if he hasnt pooped on the screen