What is the difference between a water softener and a water filter?

A water filter takes out the bad tastes and smells from water, making it safe to drink, but a water filter does not filter out limescale. A water softener takes out only the minerals that cause Limescale from the water, protecting your household plumbing and appliances from the damages and cleaning requirements of limescale.

This is the basic difference between the two systems. Some customers have both installed for the best of both worlds.

How does a water filter work?

The vast majority of filters used by consumers once water reaches our homes are made of activated carbon. Activated carbon is popular because just a very small amount has a very large surface area; just a single gram of activated carbon has the surface area of four tennis courts! A large surface area in such a compact volume means there are a greater number of very small pores available to absorb organic compounds and pollutants.

What are the different types of water filters?

Here are the different types of filter systems available and their functions.


Reverse-osmosis devices, usually installed underneath the sink, use a membrane with pores tiny enough to screen out inorganic chemicals such as chloride and sulfate. They can be expensive to purchase and may be difficult to install. In addition, they can waste as much as three gallons of water for every gallon that is treated.

Activated Carbon Filters

Carbon material—such as coal, charcoal, and wood—is used in these devices to reduce organic chemicals, such as those that can cause offensive tastes and odors. They are less expensive to purchase than many other types of treatment units and don’t waste water. Some units can enhance bacterial growth, so frequent replacement of the filter cartridge, which adds to the cost of the operation, is necessary.


Distillers are effective at reducing the levels of most chemicals except organic chemicals. A distiller boils water and then condenses the steam, removing contaminants in the process. A distiller is less expensive to purchase than a reverse-osmosis system but more expensive to operate since it uses more energy.


The simplest type of point-of-use devices, filters trap particles in a porous material while allowing water to pass through. They can reduce particles like sand and rust but cannot remove anything dissolved in the water. Filter devices are relatively inexpensive to purchase but do require regular maintenance, which adds to the cost.

Ion Exchange

Ion exchange devices—such as iron removal, softening, and chlorination systems—are normally installed at the point that the water enters the home; however, these type of water treatment devices may also be installed at the point of use.

As with most things, there are different levels of filters with associated costs. Filters with a higher grading of filtration, can often be the more expensive filters.

When shopping for a water filter, it is good practice to have in mind the reasons why you are looking for a water filter and a known your budget.

Speaking with a water system specialist like Greens Water Systems is always advised as they have expert knowledge and can advise the best system for you and your needs.

How much will the ongoing filter costs be?

As with most water systems, there are ongoing cost associated with filters.

Where as water softeners have an ongoing salt cost, the entire filter will require changing (just the filter unit, not the filter surrounds).

A water Softener system of Ion Exchange will only need changing around the 20 years mark.

A water filter will need changing much more frequently as a built in filter cleaning system is not possible to the same degree as with a water softener.

Greens would recommend the average family with average water usage, to look at new filters between 1 – 2 years depending on the filter installed. Smaller fridge contained filter jugs will need to be changed much more frequently than this dependant again on brand and type.

How often will my filter need to be replaced?

When installing a new filter, it is a good idea to confirm its average life span.

Different filters have different life spans, so you will need to consult with your product specifications or speak with a Greens expert to determine the exact life span of your chosen filter.

I might be interested in a water filter, what are my options?

So, you have decided that a water filter system is the right system for you.

We would highly recommend speaking with an expert at Greens Water Systems to discuss your specific needs before purchasing. For local customers, Greens Water Systems will also be able to install your filter as well as provide expert advice and assist you with regular free health checks should anything not be working as you expect it to.

Please call one of our friendly advisers on 01522 509 383
Or alternatively you can email: hello@water-systems.co.uk

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