ok,??so is it exspensive??evertytime I see something like this I think ,is this sanke oil??Im a heating tech,and I work on some complicated plumbing and heating systems as well as large pools,and as heat eneregy saving method Another company came in and sold the city a heat save rproduct that pumps a liquid into the pool at night and a thin alcohol based film holds the heat in,its ben a year with no savings.except there product has gummed up my heat exchangers ,Im wondering how safe this stuff is?