Silicate occurs especially in tap water or in purified water when the RO or DI unit is not functioning properly. Silicate not only results in diatom bloom but might also block some essential trace elements such as vanadium and molybdenum.
Salifert offers a very sensitive and accurate silicate test kit. Silicate content can be decreased by using the granular Phosphate-Killer or the liquid Phosphate-Eliminator. Although both are designed for phosphate removal they have also a very high affinity for silicate.

Approx. 60 tests per kit. The range is 0.03 - 30 ppm as SiO2.