Hard water is a description for water that contains a high dissolved mineral content. Water is soft when it falls from the sky as rain. As it travels through rock and soil, it dissolves calcium and magnesium, and, to a lesser extent, other minerals in small amounts. Unless you have a private well, your tap water is processed by a municipal water treatment plant to remove some of the mineral content and other impurities, but calcium (calcium carbonate) and magnesium (dolomite) will generally not be removed since they are dissolved in the water. Depending on the type and amount of processing by the municipal water treatment plant, water softness will vary from place to place. Still, in most of Canada , water is relatively hard when it leaves the treatment plant. The calcium generally originates from limestone rock, which is very common in Canada. The magnesium comes from dolomite rock which contains both calcium and magnesium.

While these minerals aren't harmful at all to your health, they do affect the properties of water and its effectiveness for washing and cleaning and for our discussion - the harm that it can do to your espresso machine! Hard water causes scaling inside the machine. Scale is the left over mineral deposits that are formed after the hard water passes through; this is also known as limescale.

You may already know if your water is 'hard' or 'soft'. Soap that lathers up easily is a good indicator of soft water. But testing is a simple, effective and more accurate way of determining how hard the water really is. This information will allow you to set your superautomatic espresso machine at the right setting (if it is a digital model). Not only will this provide the proper de-scaling schedule, but will save you money in the long term in reduced maintenance and repairs. You will also save time and money by not de-scaling unnecessarily. If you have a manual machine it will give you an idea on how often to descale your machine.

Test Strip

For commercial applications it is very important to know the numerical value of the hardness of your water, to determine the frequency of backflushing/recharging your resin water softener or when to change out your softening filter cartridge. This will require doing some basic math.

Many home espresso machines (especially the superautomatics) will have a water hardness test strip included with them. If not they can be easily ordered from our website ('teststrip').

At least ten different scales of hardness measurement have been in use over the years in various countries of the world. British, French and German to name only a few who have devised their own system over the years. Fortunately, only 3 scales are really useful in North America and it is simple to convert between them.

In Canada , the municipal water people usually chart the water hardness in mg/L( milligrams per liter equivalent to calcium). Mg/L is basically the same as ppm (parts per million) which is used on most test strips (see chart below and test strip picture above). Another common scale is gpg (grains per gallon) and the chart below shows the relationship. The actual conversion factor is 17.11 if you need to convert. The last row shows the common numbering system (1-5) used on most espresso machines.

Chart #1

Now, many of you may already be using alternate methods or sources to reduce the hardness, or to improve the taste of the water. It is very important to test this water too, especially if you are using bottled water or filtering with a Brita system or using another system. Bottled water comes from a myriad of sources with varying degrees of hardness and must be tested for hardness. It may be harder or softer than your tap water. The same with Brita and other systems (filtering is not the same as softening). Brita systems may reduce, but will not eliminate, calcium and magnesium hardness from the water when the cartridge is new. Again testing with a strip or other method is the only sure method. Similarly, the Saeco Aqua Prima cartridge and the other in-tank filter cartridges will reduce, but not eliminate the hardness. They are designed to supplement regular de-scaling routines.

So you can't see anything in the water - you're thinking ? How bad can it be? Even if I don't descale my machine regularly - no big problem, right?

Plugged Pipe

OK, try this math. A grain is defined as a unit of weight equal to 1/7000th of a pound. Another way to think of it is that a common aspirin tablet is approximately 5 grains. A household with a water hardness of 10 grains per gallon (Hard water) would have the equivalent of the weight of 2 aspirin tablets dissolved per gallon of water. So each complete fill-up of a home espresso machine (say 2 litres) will be leaving 1 aspirin's worth of scale in your machine. In a year that would be 52 aspirins for a machine in light use. That is larger than the size of many home boilers!
Or, put another way, an average household of 2, with water hardness of 7 grains per gallon, would have the equivalent of 73 lbs. of rock in their water supply in a given year!

Lime scale on element

In full sized commercial espresso machines, if the incoming water is not softened, the calcium and magnesium carbonates in the water precipitate out as solids on the surfaces of pipes and especially on the heat exchanger surfaces, boiler walls and the heating element. The resulting scale buildup can seriously restrict water flow ? causing very poor espresso delivery. In boilers, the deposits act as thermal insulation that impedes the flow of heat into the water; this reduces heating efficiency and causing damage such as failed heating elements. Most serious espresso machine damage and failure is directly related to scale buildup.

If you are using a home style superautomatic, most machines will prompt you when to descale. As mentioned, if you have a digital machine ensure you have the correct setting programmed in (chart 1).

If you have a manual espresso machine, the following chart will provide a rough guide.

Most commercial espresso machines need a reliable water softening supply. Undercounter tank style catonic ion exchange water softeners are an economical solution to this problem. The principle behind ion exchange water softening is really just simple chemistry. A water softener contains resin beads which hold electrically charged ions. The resin has been coated with sodium ions, taken from salt brine when the softener regenerates. When hard water passes through the softener, calcium and magnesium ions are attracted to the charged resin beads. It's the resulting removal of calcium and magnesium ions that produces "soft water. Espressotec carries the Rancilio DP2 Commercial Water Softener.

When the resin beads in the softener become saturated with calcium and magnesium ions, they need to be recharged. Sodium ions from the water softening salt reactivate the resin beads so they can continue to do their job.

Obviously, it will be necessary to due some volume calculations for your own particular location, in order to determine the regeneration frequency.

Full instruction are available here in PDF format
You can use common table salt, although Kosher salt is recommended.

Many undercounter filtering systems (such as the Everpure system) have water softening capability. Everpure softening cartridges are the ES0 and the 7S0. These cartridges are not meant to be recharged but are replaced after their rated service life. Generally a formula is used to calculate service life. The cartridge will have a Capacity measured in grains of softening. The formula is Cartridge Grain Capacity/Grains per Gallon(gpg)= Total Product Water in Gallons. Eg: 2,000 grain capacity/10 gpg = 200 gallons (800 litres) of softened water.

Everpure water softener cartridge