Lime from tap water can be a serious problem. Coffee makers and kettles get clogged, glasses are tinted with a white patina that is difficult to clean, and sometimes even faucets and shower heads get clogged.

That is why we are looking for ways to remove lime from tap water.

In this article we will see what lime is, what health problems it can cause, what types of lime filters exist and what is the best alternative to filter it.

What is lime in tap water?

Lime is basically the consequence of hard water. Hard water contains several minerals, including calcium, carbonates, magnesium, and manganese. If you start to see lime deposits on your coffee pot, kettle, pitchers and glasses, you probably have a “hard” water problem at home. According to the latest statistics, 85% of European and American households are affected by this problem.

Lime is a hard, off-white residue that collects on faucets, pipes, and even kettles. It is the residue left by hard water, water that contains a higher than average level of total dissolved solids (TDS) . Although hard water and lime are not dangerous, they are very annoying and can contribute to a bad taste in the water.

Is lime in tap water bad for your health?

Normally, the calcium and magnesium that form lime are not harmful to health . Lime, in the amount present in normal tap water, does not have any harmful effect on people's health. On the contrary, most of the mineral waters that are commercialized contain minerals necessary for the human body, such as magnesium and calcium. The recommended daily intake for calcium is 500-1200 mg and for magnesium 300 mg. If you drink two liters of water a day, you take in between 10 and 20% of the recommended daily amount of calcium. As for magnesium intake, drinking tap water you ingest a much higher amount, up to a third of the recommended daily.

And what about running water?

Hard water refers to water that has a high content of minerals, usually calcium and magnesium, among others. This water does not have any known harmful effects on health. According to the WHO, hard water, particularly very hard water, could represent an important contribution to the recommended daily intake of calcium and magnesium.

Epidemiological studies have been carried out indicating that magnesium or hard water have a protective effect against mortality from cardiovascular causes. Currently, these indications are debated, since they do not demonstrate causality. It is possible that people affected by some diseases should avoid hard water, such as those with kidney stones, but there is no conclusive scientific data in this regard.

How is lime removed from tap water?

Below you will find the different existing methods to remove lime from tap water.


Conventional softeners

They eliminate calcium and magnesium replacing them with sodium. This method is very effective in preventing lime build-up, but it is not very good for your health.

Inverse osmosis

It consists of installing a mesh with very small holes that allows “pure” water to pass through and prevents the passage of other elements such as calcium, magnesium or lead. Here you will find more information about reverse osmosis filters.

Ion exchange

Typically strong cation / acid resin (SAC) beads are used that reduce hardness levels and increase sodium levels by removing the calcium (Ca2 +) and magnesium (Mg2 +) ions that form. lime scale.

Its drawback is that the removal process can make the water slightly acidic (like natural soft water). If you've been drinking hard water your whole life, it may take a few weeks to get used to it. Its advantage is that with this method, you can make excellent tea and coffee. So much so, that many gourmet coffee shops use this method.

Scale inhibiting filters

These filters do not remove scale, but rather prevent it from forming to help keep your coffee maker clean. These filters use a phosphate-based chemical agent that reacts to hard water to prevent limescale build-up. Generally, the water produced by this method tastes more like carbon filtered water, although the result obtained is not as good as that of genuine scale removal cartridges.

Combination Scale Removal Filters

These filters use multiple types of media that typically incorporate granular activated carbon combined with phosphate, or that contain pyrolox or a water softening (ion exchange) resin. Depending on the type of filter media these filters contain, they either remove manganese and iron or prevent limescale formation by transforming calcium ions into calcium crystals.

A big advantage of this method is that the media mix can balance out any side effects, such as excess sodium or acidity.

Magnetic, catalytic or ionization devices

These are magic magnets that are sold in hardware stores and social networks whose manufacturers claim that they have the ability to soften water through magnetic force. Laboratory tests of these devices have generally shown that they do not work.

What method does TAPP use to remove lime from tap water?

TAPP Water has spent the last 2 years experimenting with different technologies to find the best combination of flavor, scale removal efficiency and capacity. The current version of TAPP 2 effectively removes limescale for 1 month, and no reduction in effectiveness is observed until 2-3 months. These time periods are based on tests done in Barcelona, ​​a city with very hard running water. In areas where water is hard or slightly hard, TAPP 2 will be able to effectively remove limescale from the water for a longer time.

To ensure the highest efficiency in limescale removal, we have developed a new cartridge for TAPP 2 that uses the latest carbon microfiltration block technology combined with a proprietary scale reduction formula by isolating the calcium and magnesium minerals that cause lime and corrosion.

These 3-month descaling capacity cartridges will ship from June / July 2020. We have designed them to be compatible with current TAPP 2 filters and can be used by everyone.

What are the advantages of a filter for lime in tap water?

If you live in an area where the water is very hard, with this filter:

The coffee maker or kettle will no longer have limescale.

Jugs and glasses of water will no longer have that off-white patina that is so difficult to clean.

The coffees, teas and the water you drink will taste better (if you are used to soft water).

Your Nespresso machine or other coffee makers and utensils that you regularly put water in will last longer and require less maintenance.


In summary

Lime, made up of calcium and magnesium, is the residue left by hard water.

Hard water or lime has not been shown to have harmful effects on health.

Several filtration technologies are marketed that remove lime from tap water, such as water softeners, reverse osmosis, ion exchange, and filters that combine various technologies.

TAPP 2 uses the latest combined water filtration technology to make tap water a lime-free water.