- Simply place in pump basket or skimmer basket
- Eliminates all types of Algae
- Reduces Chemicals
- Effective for up to 6 months
- Simplifies Pool and Spa Care
The 4pack of Black units is just that. 4 individual Units, each Unit supports 20,000 - 30,000 gallon pools. is an easy to use algaecide that reduces chemical demand, improves water quality, lasts for up to 6 months, and really works! contains a proprietary blend of minerals that continuously and effectively eliminates algae. Simply pick the correct sized unit based on total gallons, clean your filter first, then, drop the unit into the pump basket or skimmer. The specially treated alloy cylinder is packed with the mineral formulation.