Size Name:Pack of six Description CuLator PowerPak 1.0 removes metals up to 1ppm from swimming pool and spa water. Metal stains will start to appear on pool surfaces when dissolved metal levels reach 0.3ppm (copper 0.1ppm) - Removing metal staining is quite a complicated process and so prevention is much better than cure. In the UK the main "culprits" are copper and iron, although manganese too is putting in an appearance as faux stone surrounds are incorporated into swimming pool designs. Most metal removers work by sequestering metal ions in the pool water and then rely on the pool's filter to remove them over time. Sequestering agents can break down quite quickly releasing the metals back into the water. CuLator is different and unique in that metal ions are "captured" by the non-hazardous polymer in the CuLator bag and so doesn't rely on the pool's filtration system to remove them. Add bag to skimmer baskets. CuLator removes copper, Iron, Manangese, Cobalt, Nickel, Silver & Lead. It's non-toxic and contains no phosphates. It also lowers TDS. Change the CuLator 1.0 bag monthly (one bag will treat 75,700 Litrs pool water). (Culator will remove lanthanum in lanthanum based phosphate removers so either don't use lanthanum based phosphate removers with Culator, or don't use Culator with lanthanum based phosphate removers!)