Sequestering Antiscalants are used to prevent scaling and clogging of reverse osmosis membranes. Scale can consist of mineral foulants such as calcium sulfate, calcium carbonate, barium sulfate, silica, calcium fluoride, and strontium sulfate. Dosing of antiscalant should be done before reaching the reverse osmosis membranes to break down sulfate precipitates, calcium carbonate and other mineral foulants.

Antiscalant is the preferred pretreatment method for water systems due to its unmatched effectiveness in reducing membrane fouling. The antiscalant chemical is used to treat very poor quality feed water at very high recovery rates. When used correctly, Antiscalant extends the time between membrane cleanings from weeks to years in some cases. Without Antiscalant, ro membrane systems would not be as successful serving the water treatment industry.