I went ahead and got things started since we finally have a sunny and dry weekend. My method is going to be slightly different. I don't want to take an enclosure out of use while I do this, and I don't want the fiberglass to be permanently fused to the tank. My goal is to make a removable false bottom that will hide a container with water and a submersible pump. The shape of this false bottom will allow a little water to pool before draining into the container hidden beneath it. The tube sending the water upwards will be hidden behind a "tree trunk" fitted in the corner of the tank. The tree trunk will have a piece of mopani wood fixed to it. The water will then seemingly spring from the mopani wood, trickle (free fall about 3 inches) into the fiberglass false bottom, and drain into the water container.

I moved my snakes temporarily so I could shape the wire roughly to the shape of the tank and desired shape. I then took it outside, being careful not to distort the shape, double-checked measurements, and went ahead and laid the first layer of fiberglass. It went well. Fingers crossed.

I'm going to go ahead and hold off on showing pics right now. It's probably better if I wait until the project is completed, or nearly completed, then post pics and describe what I did all at once.