Rinse with vinegar. Pipe scale is a buildup of calcium and magnesium carbonates, and these dissolve when exposed to an acid like vinegar. Dilute white vinegar 1:1 with water and apply it to the scale. Let it sit for a few minutes and brush or rinse away the scale. Reapply as necessary to remove all the scale.
Commercial scale removal products are strong acids and care should be taken to use them in a well-ventilated area. Use rubber gloves and be careful not to splash the product on your clothes, skin or eyes. If you are exposed to a commercial scale removal product, rinse thoroughly with cold running water. Commercial scale removal products may discolor certain types of metal fittings, so read the manufacturer's warnings and instructions before proceeding.
Use an old toothbrush or a wire brush to remove thick deposits of scale. Brush away as much loose scale as possible. Apply vinegar or a commercial scale removal product and let it work for five minutes, then brush away loose scale and repeat until the scale is gone. Water softening systems will reduce or eliminate scaling problems.
Derm: Solving the scaling problem