Pond film is a type of surface film that forms on the surface of still water, such as ponds and lakes. It is composed of a variety of organic and inorganic substances, including ALGAE, SCUM, ALGAE, and SLIME. ALGAE are microscopic aquatic plants that can form large colonies and are often found in ponds and other bodies of water. SCUM is a thin layer of organic material that floats on the surface of water, often caused by an accumulation of ALGAE or other organic matter. ALGAE are also microscopic aquatic plants, but they are larger than ALGAE and can form large colonies. SLIME is a slimy substance made up of bacteria, fungi, and other microorganisms that can form a thin film on the surface of water. All of these components together form the pond film.