Hard water causes many problems
What is limescale?
Limescale mainly consists of calcium and magnesium - two minerals that by themselves have a healthy effect on the human body. However, what is good for living organisms quickly becomes a limescale problem as scale deposits in the piping system, in machinery or on surfaces around the house. So-called hard water holds high concentrations of calcium: the more calcium in the water, the harder the water and more hard water problems.
These are typical problems caused by hard water.
The birth of scale deposits
Limescale builds up as soon as hard water flows through a pipe. Calcium in untreated water crystallizes into a sticky structure (1). These crystals adhere to each other, adhere to surfaces and immediately produce solid scale deposits that have a very destructive effect. Limescale grows in particular when the water pressure changes. This happens when water changes direction in a bend or intersection which then causes turbulence; or when it leaves the piping system through a faucet. This drop in pressure enhances the formation of calcium crystals, which form a burr-like structure that adheres anywhere. Scale also particularly forms in warm areas such as on heating elements or radiators. The hotter the surfaces, the more scale will develop. Typical problem spots are heating elements, water heaters etc.
More hard water problems:
rust and bacteria
Limescale is a foreign substance to the pipe wall that causes tremendous problems by acting as blockage. It also has a destructive effect on machinery parts. Unfortunately, scale deposits also attract other unwanted substances which again create even more hard water problems and threats:
Rust - a common hard water problem in combination with limescale
Limescale consists of the main components calcium and magnesium. This would lead us to believe that scale deposits have a white color. However, most scale deposits are red. The reason behind this lies in the relationship of limescale and rust. As soon as scale deposits have built up in the hard water, all iron and oxidizediron particles imbed into the limescale. This creates the red color.This means, that rust is firmly attached to the pipe which causes a serious threat to the pipe by pitting corrosion.
Dangerous bacterial growth due to hard water
Scale deposits are a perfect breeding ground for bacteria and other unwanted micro-organisms. As the scale deposits have an uneven, rough surface, these little sockets are a perfect hide-out for bacteria to nest in. Whether it is cold or hot hard water you will face an increase in potentially dangerous substances that linger on the limescale.
Typical problems caused by hard water
Blocked piping system
Loss of water pressure due to a reduced pipe diameter
Rust accumulation in the pipes that may lead to corrosion
Bacterial growth in drinking water carrying pipes
Repeated repairs or replacement of household appliances
Replacement of the whole piping system
Loss of energy in the hot water circuit and high costs for heating
Dull surfaces in bathroom and kitchen (hard water deposits are hard to clean)
High cleaning costs and the need of aggressive cleaning agents
Hard water causes malfunctioning machinery
High production costs due to maintenance
Long pauses in production when machinery has to be maintained and cleaned leading to inefficient production planning
Decrease in productivity due to hard water
Water hardness classification
Water hardness |
ppm Parts per million (mg/l) |
GPG grains per gallons US |
°dH German hardness |
°fH French hardness |
very soft |
1-70 |
1.0 - 4.2 |
1.0 - 4.0 |
0.1 - 7.0 |
soft |
71-125 |
4.3 - 7.2 |
4.1 - 7.9 |
7.1 - 12.5 |
medium hard |
126-250 |
7.3 - 22 |
8.0 - 14 |
12.6 - 25 |
hard |
251-500 |
23 - 30 |
15 - 21 |
25.1 - 50 |
extremely hard |
501 and more |
31 and more |
22 and more |
51 and more |