Natural Chemistry PHOSfree Extra Strength is formulated from lanthanum (rare earth) compounds. When added to your skimmer, a thin coating of PHOSfree forms on the filter media. As pool water flows through the filter, phosphates are reduced to very low levels due to the lathanum and phosphate molecules sticking together. PHOSfree works inside the filter, which means no clouding of the water.

This extra strength formula removes more parts per billion or ppb of phosphates per application than any other competitive product. PHOSfree Extra Strength provides commercial properties and pool professionals an excellent tool for reducing the time spent trying to lower very high phosphate levels reliably. It will also work well on large commercial and institutional swimming pools or large residential swimming pools.

Do not add more than 1L (33.81oz) at a time. If more than 1L is needed to treat, be sure to clean or backwash the filter between treatments. Do not allow the pressure in the filter to rise to 10-12psi above the starting pressure.

Please Note:Algae must be treated prior to testing and lowering phosphates. Chlorine must be under 5ppm before testing phosphates.