FillFast Pool & Spa Home version uses two sumps and two filters to remove high levels of metals from your swimming pool fill water. Water flow through the FillFast is 6-10 gpm. FillFast removes up to 90% of all stain-causing metals like rust, iron, copper, and manganese. FillFast even removes lead. Fill your pool with metal-free, stain-free, and brilliant water. Fill fast.