How hard is your water?

How hard is your water?

As we know, laundry detergent packaging includes the recommended doses to be used depending on how hard or soft our water is. But what does this mean? Every city has a water supply with different characteristics, depending on the origin of the water and the route this water takes to reach the waterworks closest to our taps.

In Italy, if you visit the webpage http://assocasa.federchimica.it/DUREZZAACQUA.aspx, you can type in the name of your local area and discover how hard or soft your water is. Hard water has a negative impact on the washing process as detergent molecules combine with the calcium ions in the water, forming insoluble mixtures which, in addition to increasing the amount of detergent needed, also leave deposits on the fabric fibres meaning they become matted. Furthermore, substances forming lime scale may cause damage to plumbing and to household appliances, due to both their corrosive action and the lime scale they create.

The Italian association ‘Assocasa’ identifies 3 main types of water: soft up to 15°f, medium between 15°f and 25°f and hard above 25°f. Hardness is normally measured in French degrees indicated with °f (whereby one degree represents 10mg of calcium carbonate for each litre of water). Italian Legislative Decree no. 31/2001 recommends values between 15 and 50°f for all Italian waterworks. You can reduce the hardness of water by passing it through a water softener (manual or automatic) with an ion exchange resin filter: the calcium and magnesium ions are stopped by the resin which can then be used again by treating it with concentrated salt water (brine).