“…In large systems the water hyacinth is difficult to control, but in small lagoon systems it can be regulated manually. The plant has an extensive root system and is able to efficiently absorb nitrogen, phosphorus, magnesium, and iron from the water (Cooley et al 1978). Water hyacinths effectively utilize nutrients in sewage system (Boyd 1970: Gossett and Norris 1971: McDonald and Wolverton 1980.…”