Do shower filters actually work?

Shower filters promise softer hair and calmer skin, so it is reasonable to ask whether they deliver. The honest answer is that they do one job fairly well, but it may not be the job you are expecting.

What they do well

Most shower filters are designed to reduce chlorine. Chlorine is added to the mains to keep it safe on the way to your home, and it can leave a noticeable smell in the bathroom. Some people find it drying on skin and hair.

A good filter can take the edge off that. The usual filter media is KDF, a copper and zinc material that holds up better in hot water than plain carbon. People with sensitive skin are often the ones who notice the most difference, though results vary from person to person.

What they do not do

A shower filter does not soften water. This is the big misunderstanding. Hardness comes from dissolved calcium and magnesium, and removing those takes a softener. A small cartridge in a shower line cannot do this, so you will still see limescale on your screen and shower head.

It also will not purify your water in the way a drinking water system does. Water flows through a shower filter fast and hot, so the time in contact with the media is short.

Who they suit

A shower filter is a low cost thing to try if:

• You notice a strong chlorine smell in the shower.
• Your skin or hair feels dry after washing, and you want to rule chlorine out.
• You rent, or cannot fit anything larger.

If limescale is your main complaint, a shower filter will disappoint you. Look at a water softener instead.

Fitting and upkeep

Most filters screw on between the shower hose and the head, or between the hose and the mixer, and need no tools or a plumber. Check that your shower has enough pressure, because a filter adds a little restriction. Electric showers can be fussy about this.

Cartridges need changing, typically every few months, depending on the model and how many people use the shower. An old cartridge stops doing anything useful, so follow the maker’s guidance.

The verdict

Yes, they work, within limits. Buy one to reduce chlorine, and do not buy one to stop limescale. If you would like to treat the water for the whole home, see our guide to whole house filtration.