No. The minerals are uniquely chelated. This is one of the things that sets us apart from other copper-based products. Our chelation protects our minerals at a molecular level, so they DO NOT fall out of solution and stain the pool due to overoxidation or pH fluctuations. Because of this chelation, if you test for copper after using PoolRx, you will not get an accurate or consistent reading. So, if you think you have copper coming into the water from some other source, (well water, old copper plumbing, old copper heat exchanger that is leaching copper in the water, other copper based products, etc.) be sure to TEST for Copper first. If you are at 0.2ppm or less, it’s OK to use PoolRx. If above that 0.2ppm, resolve those issues before using PoolRx. Once you have PoolRx in the water your copper reading will not be reliable untile 6 months later when the PoolRx minerals have been up and filtered out.