Water hardness scale – when is hard water a problem?

Water hardness scale UK

More of the UK reportedly lives in hard water areas than not. Hard water is not always an issue, but it can cause some problems. For manufacturers and other businesses using water for processes, hard water can cause damaging mineral deposits on machinery and products.

In domestic settings, hard water can increase the amount of limescale build up in appliances and plumbing. You can see hard water marks left on glassware, crockery, and shower screens.

What is hard water?

Hard water is water that contains high level of minerals such as calcium and magnesium. These minerals are picked up as water flows though rock, meaning that hard water is more likely to be present in certain geographical areas.

See the map for where hard water is present across England and Wales


How is hard water created?

Hard water is formed when water passes over or through limestone and other rocks, for instance, when rainwater flows over land before reaching a reservoir. The rocks contain magnesium ions and calcium ions, which gets into the water. The diagram below shows the process of rain water hardening as it flows through the earth collecting dissolved minerals, before gathering as groundwater. 


Water hardness scale

The hardness or softness of water is measured by testing the water and finding out how many milligrams of mineral per litre are present. Soft water contains up to 50 milligrams per litre of these minerals, slightly hard to moderately hard water contains around 200-300 milligrams and hard to very hard water contains 300+ milligrams and above.

Water hardness scale graphic

Water hardness scale table 

What happens if you have hard water at home?

Your drinking water at home is tested for safety by your water provider. If you have hard water, there’s nothing you need to do and it’s completely safe. You may want to filter your drinking water if you prefer the taste.

You can tackle limescale using home remedies including vinegar and lemon juice and there are cleaning products for glass and showers to cut through water marks. Fabric conditioners and washing on colder delicate cycles protect your clothes. 

Should businesses ignore hard water?

Businesses who use water for manufacturing or other operational processes shouldn’t ignore hard water. Over time, the hard water leads to scale build up on pipes and heating elements. More energy is needed to penetrate the thick coating and obtain the required heat, increasing running costs. If left untreated, the coated pipework will also start to restrict the water flow too.

When hard water is left to build up on precision tools, production is stopped to clean or replace the tools, so that they continue to work at their optimum performance, resulting in costly downtime.

How can businesses hard water-proof their operations?

If your water supply is hard, then it’s important you take the appropriate action to minimise the impact it can have on your business operations.

While it’s not possible to remove hard water without using acid descales, you can arrange to prevent hardness build-up with commercial water softening systems. Once in place, it’ll immediately set to work on softening your water. The advantages of taking this route are vast, including the fact you:

  1. Will use less energy – businesses that install a water softener typically use 30% less energy.
  2. Will save money – businesses won’t have to spend thousands of pounds on acid rescaling their boiler, not to mention the cost of downtime whilst this is being done.

It’s amazing just how many businesses don’t take action to prevent water hardness because they’re put off by the perceived complexity of it when, in actual fact, it’s a really straightforward issue to tackle. All that’s required is a water softening system that’s:

  • The right size
  • Compatible with their flow rate
  • Suited to their level of water hardness

What’s more, water softeners require very little maintenance, just a service every six months and a salt supply to create brine, which is used during regeneration to replace the hard metal ions.

This article is designed to provide you with a quick  guide on hard water and it’s potential implications. For more details or to find out what impact hard water is having on your business, contact us on 0113 232 0005 or sales@excelwater.co.uk.