Fact: With the Mooiwater water softeners, a residual hardness level can be set

All our water softeners (with the exception of the Duplex power-free water softener) are fitted as standard with a mixing valve that allows us to set the residual hardness level very precisely. So if you’d like us to do that, we’ll be happy to.

Is residual hardness required?

So the question isn’t whether it’s possible, but why you’d want to do this. It’s sometimes claimed that you need to maintain a minimum residual hardness of 2dH, and sometimes even a residual hardness of 5.6dH. Well, to put it simply, you don’t have to do anything at all; it’s your water, and whether you want to make lemonade out of it or soften it to 0dH is entirely up to you.

It is sometimes claimed that the Drinking Water Decree stipulates a minimum residual hardness for water. This is not the case. The old regulations did contain a recommendation, but not a requirement. The new guidance documents no longer contain any provisions regarding residual hardness at all.

Criteria for the softening of drinking water

The old Waterwerkbad of the Association of Drinking Water Companies (Worksheet 4.6.3, June 2004) stated:

It is recommended that a residual hardness of 5.6dH be ensured.

The new Water Worksheet (Worksheet 4.6.4, January 2017) states:

4. Criteria for the softening of drinking water

4.2 Domestic installations

A monitoring programme is not required for domestic installations, nor are there any specific requirements regarding drinking water quality.

So, according to their own standards, the drinking water companies have now lowered the requirement from 5.6dH to “no specific requirements”. We can understand that, as there is absolutely no reason to remove only part of the calcium present.

Set residual hardness

With less limescale, you’ll naturally be less bothered by it, and it’ll take longer for your appliances to become encrusted with limescale and for your bathroom to lose its shine. But it will happen eventually! And why do you buy a water softener in the first place? To remove the limescale completely, surely?

If, however, you wish to retain a residual hardness (for example, 2dH), we can easily arrange this for you.

See also:

Does soft water damage copper pipes?