Chlorine and monochloramine are both toxic to fish and aquatic life. Monochloramine is harmful to fish and amphibians when it enters the bloodstream from water that passes through their gills.
Therefore, like chlorine, monochloramine must be removed from water used for keeping live fish, amphibians and other aquatic animals. This includes Koi, fish, lobster, shrimp, frogs, turtles, snails, clams and live coral. To protect fish and amphibians, use treatment products to remove monochloramine from tap water. These products are readily available at most pet supply stores and aquarium dealers. Leaving water to sit for several days is not an effective method for removing monochloramine.