Figured I'd share this here as well. I used 1/2 inch veranda PVC trim to construct the false wall and wave box on our upcoming 75 gallon display. I used mortise joints for added strength and to provide a channel for the PVC solvent cement. The internal dimensions came out to be roughly 3x5.5x12H. The hole for the WP-25 is 1-3/4 inches in diameter. This box is able to create a fairly adequate standing wave utilizing only a ~$50 pump and a ~$20 sheet of 1/2 inch PVC available at big box hardware stores.