The Problem (Iron & Manganese)
Iron and Manganese cause staining of sinks and baths and may also cause staining of laundry, especially whites. The Iron causes a brown rusty colour, whereas the Manganese, which is a metal similar to Iron, causes a blackish staining. Iron in water is often accompanied by Manganese and both have a tendency to clog pipes after several years.
Iron is often accompanied by a rotten egg smell i.e. Hydrogen Sulphide and that may come from a non-dangerous type of bacteria, or from sulphurous rock.
Iron and Manganese can also cause a bitter taste in drinking water, tea, whiskey and so on and may cause the whiskey to go black. The presence of Iron or Manganese is often detected when Milton is added to water to sterilise a baby’s bottle, as the Milton will cause the Iron or Manganese to oxidise and cause them to discolour the water.
Before Iron and Manganese are oxidised, they are said to be in solution, in that state the water will be perfectly clear as it exits from the cold kitchen tap, however, a high pH like Milton, or a high temperature like boiling, or simply by leaving it rest in the attic tank will cause it to oxidise i.e. to rust and become discoloured and very slowly deposit at the bottom of the tank.
If there is also Lime in the water, the scale formed will be brown in colour.