Purification of water for ponds or tanks containing fish

摘要

Water purification apparatus for ponds or tanks containing fish comprises a spiral/vortex settler 1 having means 5a for effecting physical flocculation of particulate matter by promoting particle to particle contact. The said means may comprise brushes or a loose or geometrically formed matrix of inert material. Water is introduced through a tangential inlet 2 and withdrawn through filters 12.