Plants, which form the main source of oxygen for any living organism, is equally essential in an aquarium. Different types of hydrophytes are used in aquariums. They not only add to the beauty of the aquarium but keeps the fishes healthy as well. The hydrophytes absorb the carbon dioxide and nitrogen dissolved in the water and release oxygen which the fishes need for respiration. Apart from this these aquatic plants are a source of food for fishes and also act as shield from enemies. Certain fishes lay eggs on the leaves of these plants, during breeding. Acorus calamus, a type of hydrophyte has very good medicinal value.
Hydrophyte act as a medium of natural feed for fish, by attracting small organisms to it. These plants are of two types – ones that float on the water surface and the ones that are immersed in water. Floating hydrophytes are used during breeding as they prevent excess sunlight from entering the tank. Also the roots absorb the fish excreta and keep the tank clean. Azolla, Pistia, Salvinia and Eichhornea are some commonly used floating hydrophytes.