[UnaClocker]

Good suggestion. I'll do that.
I went to the hardware store today to buy some plexiglass. Wasn't too impressed with their selection. They had super thin, or super thick.. .080" or .250".. I was kind of hoping for around .187" or so.. I picked up some PVC pipe for the top of the waterfall. Made a test run with it in the sink. It's surprisingly powerful with my little pump. I think I'll mock up the form for the waterfall with cardboard this weekend, so when I finally do find plexi in the size I want, I'll be ready to start cutting.
Oh, and the other problem at the hardware store.. They didn't have acryllic cement. They just had some silicone based adhesive. Am I better off with the silicone adhesive, or should I order the cement online? I've never built anything out of plexi before.. This should be interesting.