ok ill explain it now and post a pic later. there will be a sturdy 2x4 frame with 1/2" plywood and with some sort of decorative wood paneling. the plywood and frame will be sealed with a marine sealant and silicone for the edges. then a pond liner will be inside that for a leak proof design. ill post pics of it later to clarify it but thats basically how it will be. so frame, plywood, decorative paneling, and pond liner on the inside.