This skimmer can be installed directly into the side of the pond or without making a hole in the liner. It attaches to a PVC arm that protrudes from the wall of the pond via a bulk head fitting. Another method would be to use hard PVC and have it attach over the side of the pond. The basket inside the skimmer floats up with the water level which gives a little room for lower water levels before it begins to suck in air.