Hard Water Stains - Electromagnetic Water Conditioners

Electromagnetic water conditioners are a relatively new invention. The idea is that by passing water through a magnetic field, the calcium and magnesium ion's are altered in such a way that they loose their ability to cause scale.

See below for two types of electronic and magnetic water conditioners that help to reduce scale formation in pipes which may help to save hundreds of dollars on heating bills as elements in boilers and kettles do not "fur-up". Efficiency is also improved in washing machines and dishwashers as scale cannot form inside causing loss of heating control.

These devices have a number of benefits and many are used in industry; although the water is not technically soft, it has the useful properties of soft water, that is, it may reduce limescale in your pipes and may increase heating efficiency as well as lengthening the lifespan of any clothes washed in the conditioned water.

However, the jury is still out on whether these devices work effectively in a residential environment. The magnetic current that passes through the water does not technically remove the unwanted minerals but simply changes the chemical make-up of them. This is supposed to prevent the minerals from "sticking" to the sides of pipes and fixtures around the home - thus reducing hard water stains and scale formation. However, as they are still present in the water, they can still cause problems around the home. There was a period of time in the 60's and 70's where many of these anti scale devices were installed in industrial systems, however they are not used as frequently these days.

On positive aspect of the devices is that as calcium is an important dietary element, the conditioned water still retains its calcium content as it is not physically removed from the water.

Have you had any experience with these electronic descaling devices, and what did you think of them? Let me know your thoughts by leaving a comment or email me at support@hardwaterstainstips.com

Water Softeners and Filters - Discover How They Can Improve Your Water Supply

It may be useful to invest in a water filter for your home to make sure that your drinking water is clean and free from contaminants. There are different forms of water filters available today, all useful as a water softening treatment:

•Granulated, activated carbon water filters – These are portable filters that are found in water jugs. They are the simplest type of filter and removes contaminants such as chlorine, large particles and parasites. They are available at most kitchenware stores and are reasonably cheap if you have a low budget. However, they have a short filter life and don’t filter out many chemicals and bacteria.

•Carbon block, activated carbon water filters – These types of filters are generally built-in to the water supply in your home. These filters are more expensive than granulated types, but they do give better filtration and do not need to be replaced as often.

•Ceramic carbon water filters – This type of filter is comprised of a ceramic part and a carbon part; this gives it an ability to filter out a broad range of contaminants from the water supply. Some are infused with silver, as this is a good antibiotic and reduces the number of micro-organisms present. These filters are good value for money. They are built-in to the home water supply and need to be replaced about every 12 months in the average household.

•Reverse osmosis water filters – These filters are often considered the best form of water filtration available today. The water is passed through a semi-permeable membrane, which filters out almost every contaminant. They are more expensive than other types of filters but have reasonably low running costs, effective filtration and can be used to filter water to the whole house, and remove minerals that cause hard water stains in the home.

•Combination Systems – This filter has become available in recent years and are seen as an alternative to reverse osmosis systems. They have a number of different filters, and each filtration process removes different contaminants.

•Alkaline Water Machines – These systems not only filters your drinking water but it make it more alkaline. They are promoted as a good system for those with environmental illnesses where there is too much acid in the body. However, the jury is still out on how effective these machines are and whether they do indeed have any health benefit by altering the pH of the water. They do have effective filtration but can be expensive and waste a lot of water during the filtration process.

Mechanical Water Softeners

Mechanical water softening units can be permanently installed into the plumbing system to continuously remove calcium and magnesium and prevent the formation of limescale around the home.

Water softeners operate on the ion exchange process. In this process, water passes through a media bed, usually sulfonated polystyrene beads. The beads are supersaturated with sodium. The ion exchange process takes place as hard water passes through the softening material. The hardness minerals attach themselves to the resin beads while sodium on the resin beads is released simultaneously into the water.

When the resin becomes saturated with calcium and magnesium, it must be recharged. The recharging is done by passing a salt (brine) solution through the resin. The sodium replaces the calcium and magnesium which are discharged in the waste water.

Hard water treated with an ion exchange water softener has sodium added. According to the Water Quality Association (WQA), the ion exchange softening process adds sodium at the rate of about 8 mg/liter for each grain of hardness removed per gallon of water.

For example, if the water has a hardness of 10 grains per gallon, it will contain about 80 mg/liter of sodium after being softened in an ion exchange water softener if all hardness minerals (which cause hard water stains) are removed.

Because of the sodium content of softened water, some individuals may be advised by their doctor, not to install water softeners, to soften only hot water or to bypass the water softener with a cold water line to provide unsoftened water for drinking and cooking; usually to a separate faucet at the kitchen sink.

Mechanically softened water is not recommended for watering plants, lawns, and gardens due to its sodium content.

Packaged Water Softeners

Basically, these are chemicals which help to control water hardness. There are two types, precipitating and non-precipitating.

Precipitating water softeners include washing soda and borax, see image below...

These products form an insoluble precipitate with calcium and magnesium ions. The mineral ions then cannot interfere with cleaning efficiency, but the precipitate makes water cloudy and can build up on surfaces. Precipitating water softeners increase alkalinity of the cleaning solution and this may damage skin and other materials being cleaned. Washing soda is great for cleaning clothes in hard water areas but it's not used for drinking water, as explained above, the water becomes cloudy from the minerals precipitating out of the water. It would certainly not be a good idea to drink!


Non-precipitating water softeners use complex phosphates to sequester calcium and magnesium ions. There is no precipitate to form deposits and does not cause hard water stains on surfaces and alkalinity is not increased. If used in enough quantity, non-precipitating water softeners will help dissolve soap curd for a period of time.

How The Softening Process Works...

It is often desirable to soften hard water, as it does not readily form lather with soap. Soap is wasted when trying to form lather, and in the process, scum forms. Hard water may be treated to reduce the effects of scaling and to make it more suitable for laundry and bathing.

The Process

A water softener works on the principle of cation or ion exchange in which ions of the hardness minerals are exchanged for sodium or potassium ions, effectively reducing the concentration of hardness minerals to tolerable levels.

The most economical way to soften household water is with an ion exchange water softener. This unit uses sodium chloride (table salt) to recharge beads made of ion exchange resin that exchange hardness mineral ions for sodium ions. Artificial or natural zeolites can also be used.


As the hard water passes through and around the beads, the hardness mineral ions are preferentially absorbed, displacing the sodium ions. This process is called ion exchange. When the bead or sodium zeolite has a low concentration of sodium ions left, it is exhausted, and can no longer soften water.


The resin is recharged by flushing (often back-flushing) with saltwater. The high excess concentration of sodium ions alter the equilibrium between the ions in solution and the ions held on the surface of the resin, resulting in replacement of the hardness mineral ions on the resin or zeolite with sodium ions. The resulting saltwater and mineral ion solution is then rinsed away, and the resin is ready to start the process all over again. This cycle can be repeated many times.


Some softening processes in industry use the same method, but on a much larger scale. These methods create an enormous amount of salty water that is costly to treat and dispose of (see image on the left).




Temporary hardness, caused by hydrogen carbonate (or bicarbonate) ions, can be removed by boiling. For example, calcium hydrogen carbonate, often present in temporary hard water, is boiled in a kettle to remove the hardness. In the process, a scale forms on the inside of the kettle in a process known as "furring of kettles", and can also cause hard water stains. This scale is composed of calcium carbonate.

Ca(HCO3)2 → CaCO3 + CO2 + H2O

Hardness can also be reduced with a lime-soda ash treatment. This process, developed by Thomas Clark in 1841, involves the addition of slaked lime (calcium hydroxide — Ca(OH)2) to a hard water supply to convert the hydrogen carbonate hardness to carbonate, which precipitates and can be removed by filtration:

Ca(HCO3)2 + Ca(OH)2 → 2CaCO3 + 2H2O

The addition of sodium carbonate also softens permanently hard water containing calcium sulfate, as the calcium ions form calcium carbonate which precipitates out and sodium sulfate is formed which is soluble. The calcium carbonate (also known as limescale) formed sinks to the bottom. Sodium sulfate has no effect on the hardness of water.

Na2CO3 + CaSO4 → Na2SO4 + CaCO3

Health Issues of Hard Water

The World Health Organization says, "There does not appear to be any convincing evidence that water hardness causes adverse health effects in humans."

Some studies have shown a weak inverse relationship between water hardness and cardiovascular disease in men, up to a level of 170 mg calcium carbonate per liter of water.

Other studies have shown weak correlations between cardiovascular health and water hardness. The World Health Organization has reviewed the evidence and concluded the data were inadequate to allow for a recommendation for a level of hardness.

In a review by František Kožíšek, M.D., Ph.D. National Institute of Public Health, Czech Republic gives a good overview of the topic, and unlike the WHO, sets some recommendations for the maximum and minimum levels of calcium (40-80 mg/L) and magnesium (20-30 mg/L) in drinking water, and a total hardness expressed as the sum of the calcium and magnesium concentrations of 2-4 mmol/L.

Also, the National Research Council (National Academy of Sciences) advises that hard drinking water generally contributes a small amount toward total calcium and magnesium human dietary needs. It further states that in some instances, where dissolved calcium and magnesium are very high, water could be a major contributor of calcium and magnesium to the diet.

For some good information on how hard water may "stop" heart attacks, see this article at the BBC website at http://news.bbc.co.uk/1/hi/health/3396141.stm.

Testing for Hard Water

If you are on a municipal water system, the water supplier can tell you the hardness level of the water they deliver. If you have a private water supply, you can have the water tested for hardness. There are several different scales used to describe the hardness of water in different contexts.

•mmol/L (millimoles per litre)
•mg/L calcium carbonate equivalent
•grains/gallon (gpg). 1 gr/US gal = 17.11 mg/L
•parts per million weight/volume (ppm w/v or ppm m/v)

Various obsolete "degrees":

English degrees (°E) Clark degrees (°Clark) - conversion to mg/L calcium: divide by 0.175. One degree Clark corresponds to one grain of calcium carbonate in one Imperial gallon of water which is equivalent to 14.28 parts calcium carbonate in 1,000,000 parts water.

American degrees - One degree American corresponds to one part calcium carbonate in 1,000,000 parts water (1 mg/L or 1 ppm)

Degrees of general hardness (dGH)
One degree of general hardness corresponds to 10 mg of calcium oxide or magnesium oxide per litre of water

The precise mixture of minerals dissolved in the water, together with the water's acidity or alkalinity (pH) and temperature will determine the behaviour of the hardness, so single number on a scale does not give a full description. Descriptions of hardness correspond roughly with ranges of mineral concentrations:

Soft: 0 - 20 mg/L as calcium
Moderately soft: 20 - 40 mg/L as calcium
Slightly hard: 40 - 60 mg/L as calcium
Moderately hard: 60 - 80 mg/L as calcium
Hard: 80 - 120 mg/L as calcium
Very Hard >120 mg/L as calcium

As a guide, 60% of the UK and 85% of the US population live in a hard water area.

Most water softener companies will be able to supply you with a free water testing kit. Once you've tested your water supply, the hardness of your water will be reported in grains per gallon, milligrams per liter (mg/l) or parts per million (ppm). One grain of hardness equals 17.1 mg/l or ppm of hardness.