A monovalent anion. Fluoride is found naturally at low levels in some well waters, but normally its presence is due to injection into municipal water to provide a residual up to 2.5 ppm for the control of dental caries. Fluoride levels in potable waters above 5 ppm can cause mottled and brittle teeth. The rejection of fluoride by a [....]
Ion Exchange and boiler water chemists frequently report the concentration of hardness as "Grains per Gallon (as calcium carbonate equivalents)". One Grain per U.S. Gallon (as calcium carbonate) is equal to 17.1 ppm (as calcium carbonate). [....]
Conductivity is a measurement of the ability of water to transmit electricity due to the presence of dissolved ions. Absolute pure water with no ions will not conduct an electrical current. Conductivity is measured by a conductivity meter and is reported as micromhos/cm or microSiemens/cm. Conductivity is a convenient method of determining the level of ions in a water [....]
A monovalent anion. The solubility of chloride salts is high and does not create a RO scaling problem. Chloride, in seawater, is the prevalent anion. Chloride is the anion used to automatically balance a RO feed water analysis. The recommended upper limit for chloride in potable water by the US EPA and WHO is 250 ppm based on taste [....]
Color is a non-specific test that measures the relative level of organic compounds in water based on their contribution to adding color and is reported in APHA units relative to the platinum standard. [....]
A divalent anion. The solubility of calcium carbonate is low and can cause a RO scaling problem in the back-end of a RO. Calcium carbonate solubility is measured using LSI (Langlier Saturation Index) for brackish waters or SDSI (Stiff-Davis Index) for seawaters and is lower with increasing temperature and increasing pH. Carbonate is one component of alkalinity and its [....]