Hard VS. Soft Water: Can I Drink Soft Water?

16 million UK households live in a hard water area and the popular solution to this is to install a water softener. Despite the many benefits of having access to soft water, there has been a debate for some time about whether or not it is safe to drink. In this article, we provide all the facts on soft water including how it is made, what is in it, and whether it is safe to drink. 

What is Soft Water?

Soft water is water that contains a low concentration of dissolved minerals including calcium and magnesium ions. Rainwater is naturally soft when it falls from the sky – it only turns to hard water when it hits the ground. However, you can find soft water when rainfall is collected in the basin of rivers formed of non-porous rock such as granite. Naturally occurring soft water is most commonly found in the north of the UK. In the UK, water is considered soft if the hardness is less than 50 mg/l of calcium carbonate (hardness minerals).

Soft water is also produced as a result of the water softening process that takes place in a water softener. Water softeners are typically used by those living in hard water areas. Soft water is often seen as more desirable in households because it helps the soap to lather easily and no soap scum is formed. It also produces no calcium deposits and reduces limescale buildup, extending the life of your plumbing, washing machine, and kettle. Soft water is also beneficial for reducing dryness in skin and hair. 

Does Soft Water Contain Sodium?

The debate on whether soft water can safely be drunk is large because of its sodium content. Water softeners use a process called ion exchange to produce soft water. Triggering this process requires water softening salt (sodium) to be added to the hard water. In the ion-exchange process, the sodium cancels out the magnesium and calcium ions, turning the water soft. However, once the process is complete there is sometimes a small amount of sodium that remains in the water. The amount of sodium required for the ion-exchange process depends on the water hardness levels where you live. In areas with high hard water levels, more sodium will need to be added to trigger ion exchange in the water softener.

Can I Drink Softened Water?

Softened water is considered safe to drink and there is no concrete proof that there are any negative effects in drinking it. For medical reasons, the Water Supply (Water Quality) Regulations maximum sodium content for drinking water is 200 ppm (200 mg/l). The majority of areas in the UK will be well within this limit. In areas where the water is very hard, there is a small chance it might exceed this amount.

How Do I Ensure My Soft Water is Safe to Drink?

When you get a water softener fitted in your home, check with the manufacturer to ensure that the sodium levels in your water will not exceed 200 mg/l after softening. They will be able to test and confirm with you whether it will be safe to drink. If you would prefer not to drink the softened water from your supply because you are on a low-sodium diet or prefer the taste of hard water, you can always have a hard water tap installed separately. This can be installed in your utility or kitchen sink and will bypass the water softening system to provide hard tap water for drinking. Alternatively, you could install a reverse osmosis drinking water filter to reduce the sodium content in softened water.