Aquarium Freshwater Plants
In addition to making an aquarium look good, aquarium freshwater plants provide other useful purposes. They reduce the amount of carbon dioxide in the water (only when the aquarium is lit), they provide shelter, shade and sanctuary for the fish, they make the aquarium look natural, as well as providing spawning sites or food for certain fish.
Many aquarium plants are anchored in gravel by roots, but not all draw nourishment through them. Salts are also absorbed from the water through their leaves.
Aquarium plants can be classified for convenience into three groups – rooted plants, floating plants and cuttings. Of course, plants can be classified many other ways but these categories are fairly standard in the world of home aquariums.
The majority of aquarium plants available for home aquariums are rooted plants, of which there are many varieties. It is not necessary to pre-cultivate the gravel to any great extent in order for the plants to flourish. Once fish are introduced in to the aquarium, the aquarium plants will be provided with food by the action of bacteria on the excretions from the fishes.
Some aquarists provide a layer of peat or loam underneath the gravel when setting up the aquarium, placing it in nylon bags to prevent it being stirred up when the fish dig in the gravel. However this is not essential, it is perfectly possible to have gravel only on the base of the aquarium, and purchase special liquid or tablet fertilisers and foods for aquarium plants which are available from aquatic dealers.
Regarded as pests by some aquarists, floating plants do serve a useful purpose in an aquarium. They offer shade for fish from the glare of the aquarium lights, and can provide a sanctuary for newly born young fish. If there are any Gourami in the aquarium, they will utilise fragments of the floating aquarium plants when building their bubble-nests.
This is an artificially created group, because aquarium plants within this category do root in gravel, but they are more usually propagated by means of cuttings. The top section of a plant is cut off and planted in the gravel, where it soon roots and forms a new plant. It is quite common also for a loose piece of an aquarium freshwater plant to develop roots of its own accord.