Water Softening

It is important to use only soft water to run on any types of coffee machines. Most scale is calcium carbonate CaSO₄. CaCO₃ or MgCO will also make up a part of it, water softening is the most important step to follow in using any types of coffee makers.

Scale formation can cause serious problems to the machines, normally resulting in expensive repairs. It is often the main culprit to machine failure.
Restoration process like descaling is time-consuming and can cause damages to the components and metal in the process.
As such, keeping the water condition soft is the most important step to extend the longevity of an espresso machine, it is much better to prevent limescale from building than performing too much descaling.


Here are some photos of limescale formation on espresso machines used in Singapore.

Water unable to flow


Stuck valves



Clogged pipe

Clogged pipe


Water leaks when valves can’t seal.

That is not all. Scales can cover the sensors, the heating elements, and cause the machine to malfunction. As scales are solids, the restoration process will be time-consuming as time is needed to dissolve the minerals and rinse them out of the machine. Many tests are also required after the restoration.



There are many solutions available on the market.

Do note that most water softeners reduce the amount of mineral in the water but do not eliminate totally. Most solutions will have its efficacy reduced over time and require regular maintenance or replacement. If the condition of the water is very hard, the amount of limescale might not be sufficiently reduced.

On the other hand,  not all water filtration systems are effective in reducing limescale. Some will do well in removing microbes, toxic and metal but does nothing to limescale. Also, certain water filtration systems may remove all the minerals totally, this will be a problem because the water may not be detected by machines using electrolysis to conduct a signal on its water condition.  In addition to that, water which is aggressively filtered to have zero mineral, similar to distilled water, will have an erosive effect on the yellow metal within the machine. Which can thin the metal layers, and leach into the water.

Please consult a water filtration specialist to advise for more appropriate solutions.

Water softening cartridge (Recommended)











Purchase Bezzera Water Softener here
Purchase OEM Water Softener here


This is the most common solution recommended by manufacturers for semi-professional espresso machines and is only effective for home or office environment with smaller usage.
Base on the water condition in Singapore, which has a hardness of about 7 French Degrees, the cartridge works for approximately 40 litres before they must be replaced.  If you are using mineral water or if you are using in some other countries, then the hardness might be much greater and you will have to replace the softener much earlier.


Before using, rinse water softener with clean water for 10 minutes. It’s important the water softener remains in the water and does not dry out. If resins dry out, it will no longer be effective in softening the water.


For Bezzera machines with a water tank of 4 litres, this includes but not limited to Magica, Mitica, Strega, BZ16, Galatea Domus. The water tank will require a little modification to accept a water cartridge.

Bezzera modification kit for softener


For machines that have a silicon suction hose like the Bezzera BZ07, BZ09, BZ10, BZ13, Expobar Pulser, Brewtus with Vibration pump, Leva EB61.

This little cartridge can be attached to the inlet hose directly. Please remove the dirt filter before attaching the softener.

Dirt filter



BILT Oscar 150 Water Softener

BILT Oscar 150 Water Softener









Purchase here

This is a bag of resins which you can place inside the water tank. It will cure the water but it will take some time to be effective.


Effectiveness guide and softening time.

Germen DegreesPPM mg/L CaCO3Min Softening time (Hours) Max Treated LitresDrinks (100cc)

Singapore’s PUB Water Quality Rating

Average : 66 mg/L

Range across Singapore : 26 – 203 mg/L

Expiry: 12 months from purchase date or upon finishing the maximum treated litres above.

The “Min Softening time” is the time it starts to reduce hardness, it’s recommended to have the softening prolonged for 2 to 4 times longer.
Users may want to soften water in advance, done by treating the water to be used in another water vessel before pouring into the espresso machine.


They are not suitable for all Expobar or any machines with water tanks that do not have openings wide enough to insert the Oscar water softeners




Other solutions:


1. Water pitchers with filters











We note that certain brands of water pitchers with built-in filters work in reducing the hardness of the water. The filter cartridge in the water pitcher has to be replaced regularly.
As we don’t carry such products, users will have to check with the vendor or manufacturer if their models do have the capability to soften the water.

Do note that some water filters with activated carbon produce carbon dust, which might get into the boiler and cause adverse effects.


2.Water filtration systems











Some users will prefer to use a filtration system.
If you are plumping in or you are expecting heavy usage, this will be the most recommended.
Again, users will have to check with the vendor or manufacturer if their models work in softening the water.

If the filter has activated carbon, it might produce carbon dust which can transfer to the boiler.

Also some systems might purify the water too much and has absolutely zero minerals in the water, almost like distilled water. This can be an issue as distilled water has an erosive effect on the yellow metal, and it might not ignite the water detection system going by conduction via electrolysis.


3.Distilled water

It is possible to use distilled water, but the water must be remineralised by adding some minerals back. Remineralisation keeps the water from being too erosive, which reduces metal leaching into the water. If the process is properly done, it can form a layer of copper oxide on the yellow metal that protects it from further corrosion. Users who are particularly interested in exploring their coffee can use this method to control the taste by controlling the hardness.

To add the beneficial minerals back into the water.
We will suggest first adding 4.2 grams of sodium bicarbonate(baking soda) and dissolve it in 100 mL of distilled water to form a solution.
Add 2 mL of this bicarbonate solution to each litre of distilled water. This will give you 84 mg/litre.


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