BioGuard Natural Clarifier - 1 Qt BioGuard Natural Clarifier - 1 Quart This once a week clarifier keeps water clear and sparkling without the risk of over dosing your pool It causes fine sediment particles to bind together to make big particles easier to filter through Significantly improving your filters efficiency, and giving you clear sparkling water. Biodegradable, Contains no dyes or fragrance, for all pool and filter types. Cannot overdoes!