Just like certain houseplants can clean the air, some aquatic plants can clean water. Heavy metals, bacteria, oil and other pollutants can be removed with the help of wetland plants. Some of these pollutants are the result of the decomposition of dying plants and water life. While all plants are helpful, there are some that are better at pollutant removal than others.
Water mint, or Mentha aquatica, grows up to 6 inches high with light purple flowers and a mintlike look and aroma. The Water Garden website states that water mint does its best growth in full sun to shade conditions and will be hardy in USDA zones 6 through 11. It should be planted in a container then put into the water no farther down than 3 inches below the surface of the waterline. Water mint can remove bacteria such as E. coli and salmonella, according to Washington State University Extension.
The bulrush, or Scirpus spp., grows like a grass up to 10 feet in height, according to the Texas Agrilife Extension Service. It is in varying shades of green, depending on cultivar, with flowers just below the stem tip. Bulrush plants can remove oil, bacteria and other organics from the water, according to Washington State University Extension.
The soft rush aquatic plant, Juncus effusus, is another that appears grasslike and grows 3 1/2 feet high with green stems and upper stem half-flowers in a single cluster, according to the Texas Agrilife Extension Service. Washington State University Extension states that in addition to bacteria and oil, rushes also remove heavy metals such as zinc, copper and cobalt from the water.
Cattails, or Typha spp., typically grow between 5 and 10 feet high with a dark brown top that resembles a cat tail, according to Texas Agrilife Extension Service. Leaves are flat and twist on the plant. It provides wildlife cover and is a food source for some geese. Cattails remove metals such as zinc, cadmium, lead and nitrate from the water supply, according to Washington State University Extension.