How do water filters work?
Water filters pass water through one or more filtering materials designed to reduce particular substances.
Many jug filters use activated carbon to reduce chlorine and improve taste and smell. Some also contain ion-exchange material to reduce certain metals and minerals. More advanced systems may use several filtration stages or a reverse-osmosis membrane to reduce a wider range of dissolved substances.
No filter removes everything, so it’s important to check what the exact model and cartridge are designed to do.
Are water filters worth it?
Whether a water filter is worth the investment depends on your needs. For most UK households, a water filter is not essential, as tap water is already safe to drink; however, many people use one to improve taste and smell, particularly in hard-water areas where the chlorine scent may be more noticeable.
To decide whether a water filter is right for you, it's worth considering:
How much tap water do you drink
Whether you live in a hard water area
How pleasant tap water tastes without a filter
How much do you currently spend on bottled water (and the environmental impact)
Whether you’re prepared to pay more to reduce contaminants such as lead, PFAS, fluoride or microplastics
The ongoing filter replacement costs
Do water filter jugs remove limescale?
Water filter jugs can minimise limescale build-up, but aren’t as effective as using a water softener.
Filtering your tap water before boiling can reduce some of the calcium and magnesium minerals that cause limescale. However, if you live in a hard-water area, you'll likely still need to descale your kettle occasionally. Our guide to the best kettles for hard water includes models designed to make limescale easier to manage.
What do water filters actually remove?
Not all water filters remove the same things. Most jug filters focus on reducing chlorine to improve taste and smell, along with certain metals and minerals. More advanced water filters, such as under-sink or reverse-osmosis filters, may be designed to reduce a wider range of substances, including chlorine, heavy metals, microplastics, bacteria and viruses.
Always check the claims for the exact model and filter cartridge, as performance varies significantly between products.
Do water filters remove fluoride?
Some specialist water filters can reduce fluoride, but many standard jug filters do not.
Reverse-osmosis systems and certain dedicated cartridges may be designed to reduce fluoride. Always check the manufacturer’s claims for the exact model and filter used.
Can water filters remove bacteria and viruses?
Some specialist purification systems are designed to reduce bacteria and viruses, but most standard water filter jugs are not.
Never assume that a household jug or filter bottle can make untreated water safe to drink. If you’re filtering water from an unknown or natural source, use a product specifically designed and tested for that purpose.
Do you need a water filter in the UK?
It’s worth remembering that UK tap water is regulated and generally safe to drink, so for many households, water filters are used to improve taste rather than to remove harmful impurities.
Tap water can sometimes have a slightly chemical taste or smell, while households in hard-water areas may also experience more limescale. Running tap water through a filter can improve the taste of your drinking water, potentially saving you the cost and waste of buying bottled water.
If you’re living in an older home with ageing pipework or have specific concerns about your water supply, you may want to consider a more advanced water filtration system. However, it’s also worth contacting your water supplier for advice.
How often should you change a water filter?
You should change a water filter according to the manufacturer’s instructions, which may be based on time, water volume or both.
Many jug filters need replacing around every four weeks, while under-sink filters may last six months to a year. Replacing filters on time is important for keeping the system working effectively.
What is the difference between a water filter and a water softener?
A water filter is designed to reduce selected substances, while a water softener primarily targets the calcium and magnesium minerals that cause hard water.
If your main concern is limescale throughout your home, a water softener may be more suitable. If you mainly want to improve the taste of drinking water, a filter may be the more practical option.
About the author
Lucy Cotterill is a mum of two and a Content Writer at Mumsnet, specialising in baby/child and home product reviews and 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 opinions and consumer feedback to help parents make confident purchases that benefit their families.
Lucy is attempting to drink more water, so she has recently started using a Brita jug filter to improve the taste. She’s written several kitchen reviews and Mumsnet guides, including the best air fryers and top air fryer microwave combos.
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