Silica exits in a colloidal form (non-soluble) and in the dissolved (soluble) form.Reverse Osmosis removes essentially all of the insoluble form, but not all of the soluble form. Ion exchange anion resins remove most of the soluble form and ion exchange resins in general can remove most colloidal silica if any is still present in the water.

Improperly maintained resin or ion exchange beds can release a polymerized form of silica, which may be disruptive to manufacturing processes. Online resistivity meters are not sensitive enough to detect low levels of soluble silica that may pass through these beds though. It is therefore important to detect the soluble silica, the best indicator of an exhausted resin bed, before water quality interferes with production.

The most commonly employed assay is the colorimetric molybdate-reactive heteropoly blue silica assay. Our detection limit for this method is 0.05 ppb.