BioGuard Zero Phos

Does not do what it promises on the label

The product does remove phosphates but the very small print on the back says you may require more than one treatment. It depends upon how high your phosphate level is. According to the BioGuard representative I spoke to, it lowers the phosphate level approximately 5,000 ppb per treatment. The BioGuard testing at my pool store only reads phosphates up to 4,000 ppb. According ti the BioGuard representative, a “dilution test” is necessary to get an acccurate phosphate reading above 4,000. With every treatment with Zero Phos you have to clean your filters. I treated with Zero Phos once and my phosphate level was still reading above 4,000. So no, it works, but it doesn’t necessarily bring your phosphate level down to zero with one treatment in 24 hours. It depends on what your phosphate level is.