Oxygenators
Lagarosiphon major and Myriophyllum species are oxygenators—submergible, fast-growing plants that clean and oxygenate water and are used as garden accents. In sunny weather, submerged algae may turn a new pond green within a week of installation. Oxygenating plants, however, compete for the dissolved mineral salts on which algae thrive. The introduced plants starve out the mineral salts, so the water eventually becomes clear once more. Such oxygenators are essential if fish are kept in the pond.