Blue-White Variable Area Flowmeters or Rotameters are low cost easy to use flowmeters designed for measuring water flow and corrosive fluids. This type of flowmeter has been used for centuries and is one of the earliest forms of flow measurement. These variable area flowmeters have distinct advantages over newer and more technically advanced flow measurement. They are very competitively priced, require very minimal maintenance and are very accurate across their flow ranges. Blue-White has done an excellent job of designing several models to address the specific needs of the water treatment community. Several materials of construction are offered to ensure long life and durable performance even in harsh duty environments.