CuLator is a patented polymer contained in a little bag called a PowerPak. When placed into the skimmer basket or the pump basket, the CuLator removes and eliminates stain-causing metals out of pool water. CuLator prevents pool surface staining and water discoloration by removing metals from swimming pools. CuLator eliminates stain-causing metals like iron, rust, copper, and manganese. CuLator is manufactured in the USA by Periodic Products Inc.