I have a new pool, filled with water 3 weeks ago. Pool absolutely perfect except am concern by the water level which seems to be dropping. Guess there is a small leak in the underground pipes but the problem is that all is backfilled and patio laid. Does anyone know of a product that can be put into the pipe work via the skimmers for example to seal small leaks like this. I have been told that it will seal itself over a period of a few months with buildup of calcaire etc but would really like to sort this out before it is closed up for the winter.