Silicates (silicic acid) cause unsightly diatom algae. This test is used to determine the silicate content of freshwater or saltwater aquariums for diatom control. Comparative laboratory system to compensate for the water's own coloration: fill the test tubes with water to be tested, add the reagents to a test tube, place the test tubes in the test block, read the values on the colour chart. Use: new water, tap water control and in case of diatom algae problems. Included in delivery: 1 Silicate Test for approx. 50 measurements, 2 reagents, 2 glass test tubes with screw caps, measuring spoon, syringe, comparator and colour chart. Reagent refills available separately.