Although its common name is the tropical ramshorn snail, Planorbis rubrum can be kept in coldwater aquariums and even ponds. It can grow to 3 cm but 2.5 is more common it comes in a veriety of colours from brown to red ,blue ,pink ,orange and black. They are great algae grazers and will graze algae from rocks, glass and plants (they rarely eat live plants). They are also excellent scavangers feeding on detritus and left over fishfood. While it can survive in an outdoor pond, it is better suited to coldwater and tropical aquariums. Snails make up an essential part of a pond or aquarium ecosystem and would make an excellent addition to a wildlife pond.