I need input on the best way to fabricate a drain for a small (12"x12"x18") vivarium. The vivarium is currently sittng on a shelf so it would be difficult to put a bulkhead in the bottom. will air line tubing secured to the bottom under the substrate work for syphoning. I could run the tubing up behind the background and out and hook up an airlifter pump to it, just afraid that dust from the ABG mix would sift down into the hydroton and harm the airlifter. Any thoughts, comments, or suggestions would be greatly appreciated. The vivarium will be for clown tree frogs and a second possibly for phelusma klemmeri.