Contrary to popular belief, removing calcium stains from bathtubs should not be done using regular cleaning agents. Calcium is a mineral found in water in varying proportions depending upon the city water supply and when combined with magnesium (also found in the supply), hard deposits known as lime scales form. Lime scales render cleaning products much less effective so unfortunately, a bit more hard work is required when removing calcium stains from bathtubs.
Water containing lots of mineral deposits is called hard water and when it evaporates on surfaces, it is the cause of many inconveniences in the home. Larger quantities of soaps and detergents are required in order to be effective and yellow stains can be found on basins and bathtubs and reducing the life of washing machines and dishwashers.
Often when these yellow stains need to be removed, people will try a variety of regular cleaning products, only to be disappointed. Removing calcium stains from bathtubs is a matter for specialist products, formulated with just that job in mind.
With components such as citric acid as the active ingredient, these products come in liquid or powder form. Citric acid is a sequestrant, which breaks down the mineral deposits and renders them inactive as a chemical reaction. Sequestrants are used in denture cleaners as well, and this serves to illustrate its usefulness when removing calcium stains from bathtubs. Subsequently, the deactivated minerals cannot form lime scale by reacting with other materials.
Prevention is always better than cure, and the best way to avoid having to remove calcium stains from bathtubs is to install a water softener. This involves the installation of a water filtration system which can be as simple as connecting the bathtub faucet to a filter unit, or as complex as installing a whole-of-house water conditioning system. Preventing lime scale build-up in washing machines and dishwashers is considerably easier with the use of packaged water conditioners that can be added to the wash.
If you have tried removing calcium stains from bathtubs with specialist products and they have only been marginally effective, you may like to try rubbing the stain with a fine wet/dry sandpaper to break it down somewhat. Obviously it is best if this can be avoided because of the potential for scratching the surface of the tub.