The oxygenating plants are often not considered in setting up a pond, also saw their little ornamental value, but are essential plants together with purifying plants (plants for constructed wetland), for the creation of an aquatic ecosystem in balance, with clear water and well oxygenated; and offering shelter to small aquatic organisms.
A bit of chemistry, first of all!
These plants are oxygenating named for their characteristic to release oxygen in the water, the oxygen does not actually create it from scratch, but using water and dissolved CO2, as a source of electrons for photosynthesis. This biochemical process has been key to the formation of our atmosphere, in fact, cyanobacteria (primitive photosynthetic bacteria, also known as blue-green algae), through photosynthesis produced so much oxygen to make "respirable" our atmosphere and reduced the amount of CO2.
The characteristics of oxygenating plants
The oxygenating plants, in addition to their great ability to oxygenate the water, absorb carbon dioxide, many minerals and assimilate nutrients from the water and other substances responsible for the formation of single-celled algae, the typical greenish water, going to compete with them. Contribute strongly to keep the water clear. Also among the oxygenating plants, find shelter small fingerlings of fish, dragonflies and many other aquatic organisms.
The oxygenating plants live rooted in the seabed but absorb nutrients from the water. They prefer a heavy soil, even gravel, where you can cling to the roots.
Their amount should be proportional to the size of the mirror of water; insufficient quantities will create greenish or brown waters and favor the proliferation of filamentous algae and unicellular algae, while in contrast however, if their number was excessive could stifle or slow the growth in water lilies and other aquatic plants. We suggest planting oxygenating plants in wide and shallow bowls, filling the pot with soil taken from a field and covering the soil with a light layer of sand and coarse gravel.