Silica is found in all natural waters in the dissolved mineral form. Silica is only slightly soluble in water; solubility and therefore the form of silica in water depends on the pH level of the water and on the minerals containing silica in contact with water. Its presence in industrial applications is undesirable since it causes scale. In particular, high pressure turbines are highly effected by this factor. Heating systems and reverse osmosis plants also require monitoring of silica.