Natural Chemistry PhosFree 3 Liter, 05121

PhosFree is Natural Chemistry's phosphate remover, here in the 3 liter bottle, part number 05121. It is built on lanthanum, a rare earth compound, and it does its work inside the filter rather than in the body of the water.

How it works

You shake the bottle and pour the dose into the skimmer with the filter running. A thin coating of PhosFree forms on the filter media, and as pool water passes through, phosphate is pulled down to very low levels. Because the reaction happens on the media, the pool does not go cloudy the way it can with other phosphate treatments.

Getting the dose right

Treat any algae first, balance the water, and clean or backwash the filter before you start. Then set the dose from the chart using a measured phosphate level, which your dealer can give you accurately. After dosing, run the filter 8 hours a day for a week or 48 hours continuously, and do not backwash or clean it during that window. On a DE filter, if pressure climbs above its normal range, bump the filter per the manufacturer instructions and restart until pressure settles.

Keeping it there

Once phosphate reads 100 ppb or less, the program moves to maintenance: a weekly dose of Pool Perfect+PHOSfree at one cap, 4 oz, per 8,000 gallons.