Water Treatment for Commercial Glasswashers

Posted by Sara Malcom on

Hard water affects around 65% of the UK but primarily the south and east of England. It contains dissolved minerals which, when heated, become solid and form limescale.

Water Hardness Map UK

It left untreated, limescale will soon build-up inside commercial dishwashers and glasswashers, damaging key components such as the heating element, boiler and clogging water hoses, which will negatively effect the performance of your glasswasher and over time cause it to fail.

Untreated hard water will also have a detrimental effect on results. If you own a commercial dishwasher or glasswasher, you have most likely experienced issues, such as cloudy glasses and chalky residue being left on your plates and crockery, which can damage your reputation with clients.

Therefore, to maximise the efficiency and longevity of your machine, and ensure glasses are always presented without any spots or streaks, choosing suitable water treatment for your glasswasher is essential. 

Built In Water Softener

The majority of modern commercial glasswashers are available with the option of a built in water softening system, our Speedwash and Advantage Ranges included. Built in water softeners need to be regenerated regularly – at least once a day – usually when there is a break in service or at the end of the day. 

Top of the range machines, such as our Advantage Range, will alert the user when the water softener needs to be regenerated and automatically regenerate when drained down at the end of each day.

For the internal water softener to function effectively, commercial dishwasher and glasswasher salt will need to be added regularly when the warning light appears.


  • Automatic (apart from adding salt) so the softener will always function at maximum efficiency

  • Alerts the user when the water softener needs to be regenerated

  • Regeneration does not need to be carried out immediately and can be completed when there is a break in service or at the end of the day

  • Automatically regenerates when drained down at the end of the day

  • Built into the machine so doesn't require additional space


  • Only removes lime and calcium from the water - not all minerals

External Water Softener

External water softeners are required on machines in hard water areas that do not come with a built in water softener. They work by softening the water before it enters the machine and need to be manually regenerated after a certain number of washes


  • Cost effective

  • Ideal for older or less sophisticated glasswashers without a built in water softener

  • Regenerates only when capacity reached so no wastage


  • Labour intensive

  • Operator needs to regenerate the water softener manually which takes between 20 and 40 minutes, during which time the machine cannot be used

  • Additional space required to house the unit

External Water Softener – automatic

Automatic external water softeners offer a more advanced solution for machines that do not come with an internal water softener as standard. Like manual water softeners, they work by feeding already softened water into the machine. However, the water softener will automatically self-regenerate when required instead of needing to be done manually.


  • Perfect solution for older or less sophisticated existing machines

  • Suitable for any size of machine – subject to specifications

  • Low water waste – regenerates only when required


  • Space to house the unit must be available

  • Requires electric supply and plumbing

Partial Demineralisation

This method is suitable for water with ‘temporary hardness’. This means the levels of calcium ions and magnesium ions are relatively low and can be extracted by partial demineralisation filters.



  • Doesn’t remove all salts

  • Cartridges must be changed as water quality demands

  • Ongoing costs of cartridges 

Total Demineralisation

When water has ‘permanent hardness’, it will usually also contain calcium sulphate and/or magnesium sulphates which are very difficult to eradicate. Total demineralisation offers a complete water treatment solution by eliminating all major salts from the water so there are no impurities that will damage or stain glassware.  


  • A cost-effective alternative to reverse osmosis

  • Non mechanical

  • Brita Purity Clean Extra Cartridges are easy to replace

  • No electric supply needed

  • Helps optimise washing chemicals

  • Requires no maintenance

  • Cartridge needs to be changed regularly


  • Cartridges must be changed as water quality demands

  • Ongoing costs

Reverse Osmosis

Reverse osmosis first emerged in the 1950s as a possible means of desalinating sea water, and it’s moved on a lot since then. Essentially, it’s a system which forces tap water through a membrane to remove all deposits, minerals and micro-organisms. It is used in conjunction with an activated carbon filter which helps to remove many other contaminants. This method has a 99%+ filter success rate.


  • The best solution for very hard and/or contaminated water

  • Removes all impurities from the water

  • Guarantees perfect results without the need to hand polish


  • Wastes up to 6 times the amount of water produced

  • Requires regular maintenance

  • Expensive to run

  • If it fails or the filter is not changed, chlorine will cause damage to the membrane

  • If the pump fails, the machine cannot be used

To Summarise

In this article, we've explored the advantages and disadvantages of a variety of water treatment options that should help you choose the right water softening system for your operation.

If you would like some more information on anything discussed, please contact us on 020 8993 6199

glasswasher Glasswashing Guide

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