Pond covering can refer to a variety of materials used to cover the surface of a pond, such as a tarp or netting. Two common types of pond covering are SCUM and ALGAE. SCUM is a thin, film-like layer of organic material that forms on the surface of a pond, while ALGAE is a type of plant-like organism that grows in water. Both SCUM and ALGAE can be used to cover a pond, providing protection from predators and helping to maintain a healthy ecosystem.