HTH Drop Out Flocculant Clarifier 1 Qt.

Flucculant clarifier ideal to clear dull or cloudy water overnight. The fast-acting, dual-action formula drops fine particles like dirt and dead algae to the pool floor for easy vacuuming, so it will not affect pH balance or damage your filter. It also effectively removes phosphates that feed algae and improves filtration. This product is designed to work only with pools that can vacuum settled material directly to waste and not through the filter.