This innovative silicon based polish chemically bonds to the acrylic surface providing a luxurious, durable, coating without affecting your water chemistry. Helps in the prevention of scum lines and makes cleaning your shell easier. Each time you drain your spa clean the acrylic first with our "All Purpose Cleaner" and then apply "ThermoGloss". Wait 10 minutes and wipe clean leaving a beautifully enhanced and protected acrylic surface.