One of the most used of chemical treatments has been copper ion and chelated copper solutions. Their use has been extensive in public aquariums, as well as in home aquariums and ornamental ponds. However, recent scientific research has shown that the use of copper is decidedly detrimental to fishes. It should be mentioned that all of the Kordon NovAqua products, as well as Fish Protector, and PolyAqua remove heavy metals, including copper, from the water. They are highly recommended for use in water conditioning.