Water Softeners and Drinking Water: The Complete Guide to Bypass Taps

One of the most common questions before and after installing a water softener is about drinking water. Can you drink softened water? Do you need a separate tap? What about making baby formula? This guide answers everything clearly and without jargon.

Can you drink softened water?

For the vast majority of healthy adults, yes — softened water is perfectly safe to drink. The ion exchange process that removes calcium and magnesium adds a small amount of sodium. In a hard water area like Sussex (300ppm), this equates to approximately 200mg of sodium per litre of softened water.

To put that in context: a single slice of bread contains around 200mg of sodium. A glass of softened water contributes far less sodium to your daily intake than most food choices. The World Health Organisation's recommended daily sodium limit is 2,000mg — drinking two litres of softened water per day adds around 400mg, well within safe limits for healthy adults.

Who should use a bypass tap?

Despite the safe sodium levels for most people, a drinking water bypass tap is recommended in specific circumstances:

Households with babies and infants

This is the most important case. Baby formula and infant foods should always be prepared with unsoftened water. Babies' kidneys are not fully developed and cannot process sodium as efficiently as adult kidneys. Using softened water for infant formula preparation is not recommended — a bypass tap providing unsoftened water at the kitchen sink is essential in any home with a baby or young infant.

People on clinically supervised low-sodium diets

If a doctor has prescribed a sodium-restricted diet for medical reasons — typically for certain heart conditions, kidney disease or severe hypertension — using unsoftened water for drinking and cooking eliminates one source of additional sodium intake. A bypass tap is advisable.

Personal preference

Some people simply prefer the taste of unsoftened water. Very hard Sussex water has a mineral flavour that some people find pleasant and miss when it's removed. A bypass tap gives everyone in the household the choice of softened or unsoftened water at the kitchen sink.

What is a drinking water bypass tap?

A bypass tap (sometimes called a drinking water tap or third tap) is a separate small tap fitted at the kitchen sink that provides cold mains water directly from the supply — bypassing the softener. It typically sits alongside the standard hot and cold taps, or through a dedicated hole in the sink if one is available.

It's a modest addition to a softener installation — adding around 30–45 minutes to the installation time and a relatively small cost to the overall price. Given the peace of mind it provides, we recommend it on virtually every installation we carry out.

Does softened water taste different?

Many people find softened water tastes cleaner and smoother — the slight mineral edge that very hard Sussex water can have is removed along with the calcium. Others prefer the mineral taste of unsoftened water. With a bypass tap, you have the choice every time — softened water for cooking (which also improves the taste of coffee and tea significantly) and the option of unsoftened for drinking if preferred.

British Water guidance

British Water's Code of Practice on water softeners recommends that a bypass tap or other means of providing unsoftened water for drinking should be installed wherever reasonably practicable. This is the industry standard guidance and reflects what we recommend to every customer as a matter of course.