White Amur are a start. However copper sulfate works wonders but you gotta be careful not to kill too much moss at one time. There are several other products that work very well but caution is advised and if you kill too much moss at once, you will deplete Oxygen and kill your fish. Also, Moss can be removed mechanically we used to have a steel frame with pool noodle floats and hardware cloth to a depth of 8 inches. drag is across the pond with a tractor and amazing how much moss you can drag off in an afternoon (The moss is great compost)