Im not sure, but have to use it anyways. My wife and I spent $4500-5000 or so on a water refining system which covers the entire house and exterior faucets as well. We now have great water for bathing, cooking, washing, drinking etc, but im not sure what this does to my aquarium. All the contaminants/toxins are gone, but my water is to soft(lower PH) now. So with that said I have to raise my ph via chemicals or substrate.