Signs of acid water are corrosion of fixtures, pinhole leaks in plumbing, and blue staining (from copper pipes) or rust staining (from iron pipes). Often these waters are great for drinking or household use, but are low in buffering calcium minerals, and contain dissolved carbon-dioxide gas, which can cause a low pH and acid condition. Without treatment, these waters can be contaminated with copper, lead and other metals from piping, fixtures and appliances, turning good water into contaminated drinking water.

Treatment is accomplished by neutralizing the water with the use of an automatic neutralizer filter. These are water filter tanks filled with a media blend of calcium and magnesium carbonates made from naturally occurring minerals. This media, one brand of which is called Calcite, slowly dissolves into the water, raising the pH and making it less corrosive.

More mineral can quickly and easily be added as needed to the filter tank. This is typically done once per year for most residential applications. No special tools are required. This type of neutralizer also acts as a filter removing sediment and small amounts of iron.

Calcite Media

Calcite is a crushed and screened white marble media which can inexpensively be used to neutralize acidic or low pH waters to a neutral, less corrosive effluent.

Calcite is a naturally occurring calcium carbonate media. One of the advantages of Calcite is that it will only dissolve until the water reaches a neutral pH. It does not over-correct under normal conditions.

Upon contact with Calcite, acidic waters slowly dissolve the calcium carbonate to raise the pH which reduces the potential leaching of copper, lead and other metals found in typical plumbing systems. Periodic backwashing will prevent packing, reclassify the bed and maintain high service rates.

As the calcium carbonate media neutralizes the water, it will increase hardness and a softener in some rare cases becomes necessary after the neutralizing filter. However this is unusual and only occurs on water that is very low in hardness and alkalinity. Most homeowners rarely find they need a softener.

Calcite can be effectively combined with Clack Corosex to combine the high flow neutralization properties of Corosex, along with the slower reacting low flow properties of Calcite, increasing the ability to correct low pH.

How to Install Calcite Neutralizer Filters

Calcite neutralizer filters are easy to install. They need to be located in the piping after the pressure tank on a well water system, but before the copper household piping. If the pressure tank is piped with copper, it is best to remove any copper piping before the neutralizer and replace with PVC, PEX, or stainless steel piping, in order to avoid the corrosive effects of the acidic water.

Neutralizer filter tanks for home water systems typically measure 10 or 12 inches in diameter and 48 to 54 inches in height. The tanks have a center tube about 1 inch in diameter, called the distributor tube, which have a screen at the bottom of the tube. When the neutralizer tanks are assembled, the distributor tube is first placed in the tank and some tape or a cap put on the top of the tube to prevent media or gravel from entering the tube when the filter is built. Approximately 10 to 20 pounds of aquarium gravel 1/4 inch in diameter is first poured into the tank to cover the bottom distributor screen. The calcite media, which looks like white sand, is then poured in until the depth of the media reaches about two-thirds of the tank.

The top one third of the tank is left as free space. This free space allows the media to expand when the neutralizer is backwashed.

Neutralizer filters need to be connected to a drain to allow the filters to backwash. The backwashing is done automatically based on a simple timer typically once every one to two weeks. This flushes out any sediment or iron that the neutralizer filter has trapped and keeps the calcite clean and properly settled so it can filter and raise the pH in an optimum manner.

Up-Flow Neutralizers

An effective neutralizer filter uses an automatic backwash control valve, which allows the owner to have the neutralizer tank be automatically cleaned every one to two weeks.

In some cases, no backwash control valve is used and instead of the water first flowing down through the media and up the distributor tube, the piping is installed so the water flows down the distributor tube and up through the media. This is called an "up-flow neutralizer" and they are not backwashed.

There are some disadvantages to up-flow neutraliers despite the lower costs. In some cases calcite media can wash out of the neutralizer and enter the home water piping system causing damage. If the water flow is not sufficient the media can become solidified in places, causing the water to bypass the media.