I built mine with cement block my neighbor gave me. After the blocks were laid I covered the inside with cement and sand mixed with a liquid latex. After this dried I painted the inside with drylok extra. I also covered the outside with sand and cement. I built a waterfall by building a shallow pond that is elevated above the main pond and used cardboard tubes filled with cement to support it. The suspended pond is filled with local rock to use as a filter. We covered the outside with pebble mosaic. It took about a year to build but it still holds water. The mosaic has pealed in places but it still looks half way decent. I need to do some repair but its so dang hot right now.
