Treating Acidic Water

If your water pH is below 6.8, you may be experiencing blue or green stains on your fixtures or a blue-green color to your water caused by a reaction between the water and your copper or brass pipes or fittings. Acidic water conditions are normally caused by dissolved carbon dioxide as well as a lack of bicarbonate alkalinity. Acidic water itself can be an issue as well as causing high concentrations of lead, zinc and cadmium caused by corrosion of plumbing fixtures.

In order to properly treat acidity in your water, you should first test the pH to determine the best method of treatment. You can test the pH of your water with an inexpensive test kit or a basic handheld electronic test meter. For more industrial applications or for multiparameter (multifunction) meters we recommend the Myron L series of handheld meters.

Correction of Low pH using Calcite

If your water is between a pH of 5.5 and 6.8, a bed of calcite (calcium carbonate) can be used to effectively raise the pH. Calcite reacts with the carbon dioxide dissolved in the water to form Calcium Bicarbonate (calcium hardness). Because hardness is increased by 3 to 5 grains for every point of pH increased using calcite, the use of a calcite bed ususally precedes a water softener which is used to remove the subsequent hardness. An advantage of using calcite to correct low pH is that you cannot overcorrect for pH. Under normal conditions, water treated with calcite will level off around 7.2 pH.

For low flow applications like undersink filtration, refillable water filters can be filled with calcite bulk media and used in a standard filter cartridge housing. A disadvantage to using calcite in cartridge filters is that a backwash cycle is not performed so pressure drop may necessitate the changing of the calcite media before the media is exhausted.