Hard Water Stains On Showers And Glass

The hardness of water is represented by the calcium and magnesium ions in the water. The hardness of water is defined as total parts per million (ppm) of CaCO3 by weight. For example, the hardness of water 10 ppm means 10 g of CaCO3 in one million grams of water or 0.01 g of CaCO3 in 1-L water.

You may remember waking up to your car littered with white spots after a sprinkler being on top of it. Over time these may build up on shower screens or glass facing close to any tap water sources. It is difficult to remove and requires specialist techniques. In the industry this is labelled as glass restoration and would not be included with a general window clean.

Phosphoric acid can remove hard water staining but extreme care must be taken on all the seals around windows as it may damage, rubber, wood and plastics.