Spa Perfect is specifically formulated for hot water temperatures and is a patented natural enzyme and botanical extract formula that powerfully, yet gently biodegrades body oils, cosmetics, suntan oils, and other non-living organics. No more waterline rings, clogged filters or cloudy smelly water. Spa Perfect is also a continuous cartridge filter cleaner. Since oils and non-living organics don't build up, soaking with nasty chemicals and acids is rarely required. 1 liter size.