Airmax D-Scale Fountain & Aeration Cleaner is a powerful multi-functional fountain cleaning solution that deep cleans and removes limescale, calcium, rust stains, and other mineral deposits. Quickly and easily clean fountain floats, boats, motors, waterfall pumps, impellers, air stones, diffusers, and more. 100% biodegradable, Airmax D-Scale Fountain Cleaner's fast-acting foaming formula works on contact without scrubbing or releasing harmful chemical fumes. This is a perfect replacement for other harsh cleaners such as hydrochloric or muriatic acid. Just spray, set, and rinse.