Best dishwasher salt, plus how to use it
Do you live in a hard water area or simply want to prevent a build-up of limescale in your dishwasher? Here are the best dishwasher salts to help protect your appliance, plus tips on how to use them effectively.
By Lucy Cotterill | Last updated Apr 12, 2024
Adding an energy-efficient dishwasher to your home can certainly be a wise investment. Using less water than washing dishes by hand, the best dishwashers can be a quick and efficient way to clean up after dinner - taking just a touch of madness out of midweek mealtimes.
Whether you opt for a freestanding or integrated dishwasher, once you’ve chosen your appliance, it’s important you look after it to keep it running at its best. While rinse aid can improve drying performance and add shine, using dishwasher salt can help protect your dishwasher from limescale and residue build-up. This can not only ensure good cleaning performance, but it can also prolong the overall lifespan of your dishwasher, especially if you live in a hard water area.
With much debate about dishwasher maintenance on our forums, we sought out tried-and-tested views and tips from Mumsnet users. We also then consulted expert feedback and authentic consumer reviews to find the dishwasher salt products real people like you have in their own homes and would happily recommend to others.
Here are the best dishwasher salts you can buy today, plus guidance on how to use it effectively.
Best dishwasher salt UK: at a glance
Mumsnetter trusted brand
Softens water to improve cleaning performance
Prevents residue build-up in your dishwasher
Helps remove watermarks and spots
Brand recommended by dishwasher manufacturers
Costly
Price on writing: £10 | Size: 4kg
When it comes to dishwashers, Finish is a brand that is trusted by Mumsnet users and industry experts alike. This dishwasher salt comes widely recommended by dishwasher manufacturers including Bosch, Siemens, Beko and Neff, which offers significant peace of mind when making your choice.
Made from coarse 99% pure and premium quality salt, Finish effectively softens the water to prevent residue build-up and improve cleaning performance, so you won’t find watermarks or spots on your glassware.
While it seem pricey initially, this 4kg box offers good overall value for money and is easy to pour into the salt reservoir directly from the box.
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Budget-friendly price tag
Easy pour spout
Smaller box more convenient than storing large bags
Reviewers found salt lumps were larger than competitor brands
Price on writing: £2 | Size: 1kg
While Finish is the leading dishwasher salt brand, you can pick up smaller packs of supermarket own brand dishwasher salt at a more budget-friendly price.
Sainsbury’s Dishwasher Salt may not be as coarsely grained as leading brands, but reviewers found it performed well, dissolving well in the wash to prevent limescale build-up and watermarks.
With an easy pour spout that allows you to use it straight from the box, this smaller package is also easier to store than larger bags, reducing the risk of spillages in the cupboard under your sink.
A large 5kg bag offers good value for money
100% pure coarse grain salt
Prevents spots and watermarks
Effective in hard water areas
A larger bag is harder to store between uses
Price on writing: £9 | Size: 5kg
If you are happy to store larger bags, this 5kg bag of HSD Dishwasher Salt offers excellent value for money and impressive performance.
A 100% pure coarse grain salt, it works well even in hard water areas, dissolving well to soften the water during the cycle, preventing spots and watermarks without leaving any residue behind.
Recommended for use every four weeks, HSD Dishwasher Salt can help improve your dishwasher's performance by descaling the pipes, spray arms and filters.
What is dishwasher salt?
If you live in a hard water area, excess minerals such as calcium and magnesium that are found in your water can lead to a build-up of limescale on your appliances - including your kettle, washing machine and dishwasher.
If left untreated, limescale in your dishwasher can not only look unsightly - it can affect its overall performance and even reduce its lifespan.
Dishwasher salt, in the form of coarse granules, can help combat the effects of hard water when added to your dishwasher by softening and removing minerals from the water during the wash.
Related: The best kettles for hard water
What does dishwasher salt do?
Dishwasher salt helps ‘soften’ the water during the wash cycle, removing excess minerals that can cause limescale and residue build-up. Not only can this improve your dishwasher’s overall cleaning performance, but it can also prolong the lifespan of your dishwasher, protecting the arms and spray heads as well as hard-to-reach areas where residue can build up inside your appliance.
I use all-in-one tablets. Do I still need to use salt?
If you live in a soft water area, using all-in-one dishwasher tablets may be enough to protect your dishwasher. However, they only contain a small amount of salt. If you live in a hard water area, it is recommended you still use a separate dishwasher salt to adequately prevent a build-up of limescale.
You can check how hard the water is in your area here.
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How do I use dishwasher salt?
The amount of dishwasher salt needed will depend upon the size and make of your dishwasher, so be sure to check the manual before using salt for the first time.
In most cases, dishwashers will have a salt reservoir underneath the bottom rack, with a screw top that needs gently removing to fill. Gently pour in the salt being careful not to overfill or spill loose salt onto the floor of the dishwasher - you may want to use a funnel to do this.
Once filled, close the compartment and reapply the cap. Some dishwasher brands suggest that you run a rinse cycle after refilling to ensure that any loose salt is dissolved before use.
Can I use normal salt in the dishwasher?
No - dishwasher salt is not the same as table salt or cooking salt. Dishwasher salt is not only specially formulated for dishwashers, it's also made from larger granules that dissolve more slowly to help prevent limescale build-up.
What is rinse aid?
Rinse aid works by lowering the surface tension of water, preventing droplets from settling on the surface of your dishes and glassware. It can be added to your dishwasher to enhance the drying performance and prevent unwelcome watermarks, streaks or spots from forming, especially in hard water areas.
How we chose the best dishwasher salt
Advice from real Mumsnet users
Mumsnet users love their dishwashers, but maintaining them can be a bit of a mystery. As such, there are lots of chats in the Mumsnet forums on how to add rinse aid and dishwasher salt, particularly for users in hard water areas.
Expert opinions
Next up, we considered reviews and feedback from trusted industry experts. We want to be confident that the dishwasher salts we recommend are fit for purpose, so we looked out for award-winning and high-quality products, including those endorsed by dishwasher manufacturers.
Authentic consumer reviews
Finally, to bring you our definitive list of the best dishwasher salts on the market, we thoroughly investigated genuine, in-depth customer reviews on retailer sites such as Amazon, Sainsbury's, and other online supermarkets to get wider consumer experiences regarding the products on our shortlist.
About the author
Lucy Cotterill is a mum of two and a Content Writer at Mumsnet, specialising in lifestyle product round-ups. Having written reviews on her own blog Real Mum Reviews since 2012, Lucy loves to research and explore the pros and cons of products, scrutinising expert suggestions and consumer feedback to help people make confident purchase decisions.
Having bought her first ever slimline dishwasher in 2022, Lucy knows only too well the benefits that a clean and high-performing dishwasher can bring when juggling family life. While she lives in a soft water area, Lucy ensures she uses the best dishwasher cleaner, rinse aid and dishwasher salt to keep her appliance running at its best.
Lucy's also written several Mumsnet round-ups on dishwashers, including the best budget dishwashers, quietest dishwashers and most energy-efficient dishwashers, so she knows a thing or two about keeping appliances running at their best.
Why you should trust us
We work hard to provide honest and independent advice you can trust and we spend hours scouring the Mumsnet forums and online bestseller lists to find products that real parents rate.
Transparency is really important to us and that's why we're always upfront about where we find our recommendations. We write about products that we feel offer the best value to most parents – the ones that our users would recommend to their own friends and family.
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