Hard water contains a high level of lime particles in the form of calcium carbonates, also known as calcites, which come from areas where underground water sources are in direct contact with chalk-producing materials, such as limestone or marble. The water absorbs the calcites from the minerals and maintains them in a suspended state, leaving scales on surfaces that hold the water. When the water is heated, the scaling residue worsens, resulting in lime deposits on tea kettles and coffee pots. There are a few techniques for removing lime from water.
Soften hard water with a commercial water softener, installed on your water line before the water enters the hot water heater. A water softener uses specially-formulated salt pellets that slowly dissolve in the hard water and counteract the mineral deposit’s ability to adhere to surfaces. With this method, your household water will be “softer” and less likely to produce lime deposits.
Take a sample of your water for testing to set your water softener correctly. You must adjust the flow of water through the salt pellets according to the amount of minerals present. Call your country extension agency to find a local testing facility.
Install a reverse osmosis (RO) unit on your drinking water to remove lime deposits (see Resources). The water softener just counters the minerals with sodium salts but to remove them for human consumption, a reverse osmosis unit is in order. An RO unit contains a special membrane that does not allow large molecules to pass, effectively removing most minerals from drinking water. The downside is that these units service only one faucet.
Distill your water to remove lime deposits. Distilling is a method of heating water until it becomes a vapor and trapping that vapor in a series of tubes until it condenses into a different container. The condensed water will not contain the heavier mineral deposits that were present in the original sample.
Drop chemical additives into toilet tanks to alter the composition of the minerals present in hard water, thereby reducing lime deposits on the inside of the toilet tanks and bowls. These additives are in the cleaning aisle of the grocery and come in blue, green or clear colors. Make sure your pets do not drink the treated water.
Use municipal water in an area where reverse electrodialysis is one of the methods used to treat the water. Similar to the ion exchange system in an RO unit, reverse electrodialysis uses a large membrane to remove minerals and waste products on a bigger scale.