Science Behind Filtered Water

The Science Behind Filtered Water

This page sets out what is actually in UK tap water, what a shower filter can and cannot do about it, and where the evidence is strong or thin. We would rather you bought a VORASSO filter knowing the limits than be disappointed later.

What is in British tap water

Chlorine. UK water companies are required to disinfect mains water, and chlorine or chloramine is how they do it. That disinfection is a public health success and we are not suggesting otherwise. The residual chlorine that reaches your shower is safe to drink by design; it is also what gives a hot shower its faint swimming-pool smell.

Hardness. Around 60 per cent of UK households are supplied with hard or very hard water, concentrated across the south and east of England. Hardness is dissolved calcium and magnesium picked up from chalk and limestone. It is harmless to drink. It is also what leaves limescale on your screen, dulls soap lather, and leaves a film on skin and hair after washing.

Trace metals and sediment. Water leaves the treatment works clean and then travels through decades-old mains and your own household pipes. Small amounts of iron, copper, rust and sediment can be picked up on the way, particularly in older properties.

You can look up your own supply. Every UK water company publishes a water quality report by postcode, and the Drinking Water Inspectorate regulates them.

Why a shower is different from a glass of water

A shower exposes a large area of skin to a large volume of water, warm, for several minutes. Warm water also drives some volatile compounds, including chlorine, out of solution and into the air of a small enclosed room. That is why a filter on a shower is doing a different job from a filter on a drinking tap, and why the chlorine smell is stronger in a hot shower than at the kitchen sink.

How the filter media work

KDF-55. A copper-zinc alloy that works by redox: an electrochemical exchange that converts free chlorine into chloride, which is inert and odourless. It is a genuine chemical conversion rather than simple trapping, it works well at shower temperatures where carbon alone struggles, and it is bacteriostatic, so the cartridge does not become a place for bacteria to breed.

Activated carbon. An enormous internal surface area that adsorbs chlorine by-products, organic compounds and the compounds responsible for taste and smell. Carbon is the workhorse of water filtration and the reason filtered water smells different.

Calcium sulphite. Neutralises free chlorine quickly and keeps working at the higher temperatures a shower runs at.

Ceramic balls and fine mesh. Catch rust, grit and sediment before they reach the finer media, which is what keeps the cartridge working for its full service life.

What a shower filter does not do

We would rather be straight with you.

• It does not soften water. Softening means ion exchange, which requires a plumbed-in unit with a salt reservoir. A shower filter reduces chlorine and sediment; it does not remove dissolved calcium and magnesium, so it will not stop limescale on your taps.
• It is not a drinking water purifier. Do not treat a shower filter as a substitute for a drinking water filter.
• It does not treat any medical condition. If you have eczema, psoriasis, dermatitis or any other skin condition, see a GP or dermatologist. A shower filter is a comfort and water-quality product, not a treatment.
• It does not last forever. Media are consumed as they work. Once a cartridge is exhausted it filters nothing, which is why replacement every three months matters more than any specification on the box.

What to realistically expect

Most people notice the chlorine smell has gone within a shower or two, and that soap and shampoo lather more easily. Beyond that, individual results vary a great deal, and how you get on depends on your water, your skin and your hair. We think that is worth saying plainly rather than promising a transformation.

Getting the most from your filter

• Replace the cartridge every three months, or sooner in a hard-water area.
• Flush a new cartridge for 30 to 60 seconds before first use.
• If flow drops noticeably, the cartridge is telling you it is full. Change it.

Questions

Email hello@vorasso.com or call 0121 236 9936, Monday to Friday, 9:00 to 17:00 GMT. VORASSO is a trading name of Art Engraving, 60 Northampton Street, Birmingham B18 6DX, United Kingdom.

The information on this page is general and is not medical advice. VORASSO products are not intended to diagnose, treat, cure or prevent any medical condition.