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How Hard Is My Water? Water Hardness and Quality Map and Checker

How Hard Is My Water?

People often ask: how hard is my water? If you live in the UK, it’s quite possible that your water is very hard.

In some areas, it can be a serious problem that affects the quality, taste and cleaning ability of your water. It can also damage your home appliances.

How do I know my water hardness?

There are several things you can do to check the hardness level of your water.

You can test it yourself, go online, or have a professional come to your home to test it for you.

How do you know if you have hard water in your home?

There are a few ways you can check your water hardness yourself:

You might be able to taste hard water.

Pure, clean water has no taste, so if you can taste something in your water, it could be hardness causing minerals like magnesium or calcium carbonate.

You might notice that your washing machine needs more detergent to clean your clothes adequately.

Or you might need more soap or bath gel to lather when bathing.

The most obvious indication is the furry deposits

Check the heating element in your kettle and the metal parts of other household appliances that come into contact with water.

You can put some tap water into a clear container and adding 5 – 10 drops of pure liquid soap.

If you shake the container, soapy bubbles should form. If they don’t, you probably have hard water. The more drops you need to make your water soapy, the harder your water is.

Check the Map

Check this map of hard water limescale areas in the UK

If you're in a border area, most water suppliers in the UK have a webpage that indicates the levels of hardness in your area.

Vist your local suppliers website and enter your postcode.

What is Hard Water?

Most people know that the minerals in UK tap water – mainly magnesium and calcium – can affect the quality of the water in their homes.

These minerals make your water “hard” and give it taste, in addition to being responsible for the problems cause by scale.

How is hard water created?

Water is soft when it falls from the sky, but by the time it has arrived at the reservoir, it might have collected minerals after coming into contact with soil and rocks.

Water that runs through porous rocks, such as limestone, dissolve particles of the rock and they are absorbed by the water.

How is hard water measured?

Hard water is measured in the UK by 2 different scales: Either a CLARK degree or as Calcium carbonate CaCO3 “parts per million” (ppm) in mg/L.

Devices measure how many mineral particles are dissolved in your water to ascertain the level of hardness. Anything under 50 ppm is considered soft water.

Water Hardness Chart

If your water is between

- 0 to 50 ppm (0 to 3.5 Clark degree) is soft

- 101 to 150 ppm (7.1 to 10.5 Clark degree) it is slightly hard

- 151 to 200 ppm (10.6 to 14 Clark degree) is moderately hard

- 201 to 300 ppm (14.1 to 21 Clark degree) is hard

- Over 300 ppm (21 Clark degree) is hard

Issues related to hard water

It has been estimated that hard water costs the UK over £1 billion annually.

There are four main issues related to hard water:

- Poor taste affecting drinking and cooking

- Difficulty bathing or cleaning and washing

- Damage to home appliances, boilers and water systems

- Increased running costs due to inefficiency and wear and tear

Many people do not like the "stony taste" of tap water and prefer to use bottled or filter water for drinking and cooking.

(Hint: Bottled water is very bad for our planet. There is a wide range of drinking water filters you can choose from. These save you money and are much greener).

A big issue faced by households in hard water areas is washing and bathing.

Hard water prevents soaps and detergents from lathering, and this often means that cleaning or washing is difficult or that you need to use more soap or detergent to do the job effectively.

Hard water also affects home appliances, water pipes, and boilers.

It leaves scale deposits that result in damage or the breakdown of appliances and machinery, and often leads to higher running costs due to increased power consumption, inefficiency, and higher maintenance costs.

Limescale build-up also does not look very nice on your metalwork.

Is hard water bad for you?

Hard water is not bad for you. In fact, some people believe it is good for you because it contains minerals your body needs.

However, almost everyone gets these minerals in adequate amounts from the food they consume.

How can I reduce the effects of hard water scale?

The best way to reduce the effects of hard water on your home is to install a product that eliminates the scale from your water.

Most people concerned about hard water buy a water softener system for their home.

There are a several options depending on the needs of your household.

You should thoroughly investigate which is best for your household before making a decision.

If you simply want to drink filtered water, you could install a tap filter under your sink. If you want to eliminate scale you will need to purchase a water softener system.

What is a water softener?

There are two main options when installing a water softener system:

- A saltwater softener

- A salt-free water softener

Each system works differently, but both soften your water before it reaches your taps.

The chemistry bit:

Different types of water softener systems use different processes in order to soften your water.

Saltwater softeners pass water through a tank containing resin beads.

Through a process of ion-exchange, the beads turn the hard water into soft water by attracting and trapping the hard-water-causing minerals.

The water then flows into your pipes after the process. The resin beads are then flushed with salt in order to regenerate them.

In effect, you are replacing the minerals, mostly magnesium and calcium, with salt water.

Salt-free water softener systems, use media - typically in cartridges - to filter the unwanted minerals from yourwater and inhibit the build-up of scale.

Technically, they are filters or conditioners, but the terminology most used and understood by the public is “water softener” which is why they have come to be known as saltless or saltfree softeners.

Types of water softener:

There are various types of salt-water systems, including those with single or twin tanks, and those that use block salt or salt purchased in bags.

Because saltwater softeners use salt, you must add a separate by-pass tap if you wish to use tap water for drinking.

Salt-free water softeners, as the name suggests, do not use salt because they condition or filter the water through media cartridges designed to modify the structure of the water in order to inhibit the build-up of scale.

Salt-free systems include smaller products such as tap filters, as well as larger whole of house conditioning systems with scale reduction.

Many people choose a salt-free water softener because of the benefits when compared to a system that uses salt. Salt-free softener systems:

· Use less water

· Do not contain salt, so the tap water can be used for drinking

· Require less maintenance.

Timed regeneration:

As saltwater softeners use salt to flush or “backwash” the resin beads in their tanks, salt must be continually added to the system to “regenerate” the beads.

The problem is knowing when the beads need regeneration.

To solve this problem, saltwater softener systems include a timer that schedules the process of regeneration. Most systems set the timer to regenerate at low peak times when high water demand is less likely – 2 am, for example.

The problem is that the system will regenerate the beads whether they need it or not, consequently increasing your water and energy consumption.

The other problem with timed regeneration is that the beads might need regeneration at 6 pm but the timer is set for 2 am and you have just arrived home and need to shower and do your laundry.

In this scenario, you will be using hard water until the regeneration cycle can flush the resin beads again.

Metered regeneration:

Metered regeneration is a recent technology designed to eliminate water and salt wastage in saltwater softener systems. It is also called demand or volume regeneration.

The system measures how much water is flowing through the softener system and then regenerates the beads as needed.

Once the metered regeneration system detects that your beads need regeneration, it begins the backwash so that your system can continue to work effectively.

What capacity options are there?

Almost everyone living in the UK can buy a water softener system with a capacity suited to their home.

Small bedsits or large homes, even commercial applications, can be accommodated.

The best way to find out what you need is to consult a qualified supplier with a good reputation for customer service. The system capacity you need will be determined by:

- The size of your household and average water usage

- The hardness of your water

- The system you choose

- Your needs (drinking only, whole of house system etc.)

Maintenance and installation

Purchasing a water softener system is not the only cost you should consider after you have answered the question “how hard is my water?”

Almost all water softener systems need maintenance and, depending on the system you choose, might require a plumber to complete the installation.


The maintenance requirements differ if you have a saltwater system compared to a salt-free system.

For a saltwater softener, experts say that every six months you should check the hardness level of your water and ensure that the settings on your system are aligned with your water hardness level.

Some people also suggest that you disinfect the water softener every year by adding disinfectant to the water tank and also clean out the brine tank every two to three years.

Of course, you must constantly add salt to your saltwater softener system as needed.

Less maintenance is required for salt-free water softener systems,

For example our Salt-free systems simply need the cartridges replaced every 2 years - which only takes a few muinutes.

More info here


Water softener systems can be installed in various locations around your home.

They can be installed under the kitchen sink, in a utility room, the garage, or other suitable areas of your home.

Some water softener systems must be installed by a qualified plumber. The installation is usually not complex, but you should get advice from your supplier to make sure you are aware of all the associated costs.


You should make sure your supplier offers a comprehensive warranty.

Most companies give a 12-month warranty and some even offer 3-year warranties.

Ask your supplier if they offer a money back guarantee on your purchase to further protect yourself.

Many have 30-day money back offers, and some (like us) offer up to 90 days.

Drink to your health

Our water filter systems can remove harmful pathogenic bacteria, cysts, parasites, and unhealthy chemical contaminants such as Chlorine, while at the same time leaving in the essential minerals your body needs.


Save money on bottled water purchases by regularly usingfiltered water. Get your highest quality water filters at the best price here.


We supply the widest range of water filters for any needs - residential or commercial.