Use this kit to test for phosphates in water. A variety of visual kits are available using either the Stannous Chloride or Vanadomolybdophosphoric Acid method. Kits vary in Range (anywhere from 0-12,000 ppm) and MDL (anywhere from 0.05 ppm to 200 ppm). Each kit includes enough materials for 30 tests. Refills can be purchased.