Magnesium sulfate (MgSo4) does not cause hardness of water.
FeSO4
Hardness of water pretains to the concentration of minerals and other trace elements in your local water supply. Well water-such in my area is "very hard"-meaning it contains a large amount of iron and other minerals-when boiled down in a pot of the water on your stove-it will leave a deposit on the pan once the water has boiled away. A water softener helps filter out these particles.
Permanent hardness is hardness (mineral content) that cannot be removed by boiling. It is usually caused by the presence in the water of calcium and magnesium sulphates or chlorides which become more soluble as the temperature rises.
Soaps get precipitated as insoluble calcium and magnesium soaps in hard water but detergents do not. Therefore, soaps but not synthetic detergents can be used to check the hardness of water.
no it's the mineral content
Sodium chloride is not the cause of water hardness.
FeSO4
Yes. it causes temporary hardness of water, which can be generally removed by boiling water.
calcium and magnesium
Permanent hardness in water is hardness due to the presence of the chlorides, nitrates and sulphates of calcium and magnesium, which will not be precipitated by boiling.
If the calcium is a result of pool chemicals, draining some or all of the pool water will lower the calcium hardness level. If the cause is the fill water, commercial hardness reducers or chelating agents will bond with the calcium to keep it trapped in solution.
Salt is sometimes used to remove water hardness. Borax and soda are generally used as well to remove water hardness.
Temporary hardness of water: CaHCO3, MgHCO3 Permanent hardness of water: CaSO4, MgSO4
The water supplier can provide you the details on hardness level if you are on municipal water systems, If you are using private water then you can get tested in laboratories. You can even measure it with water hardness testing kits which you need to purchase.
Hardness in water is usually characterised as temporary or permanent. Both are due to the presence of calcium or magnesium ions. If they are present as the hydrogen carbonate, when the water is boiled this is converted to the carbonate which precipitates out as a solid, leaving water which is no longer hard, so this is called temporary hardness. If they are present as the sulfate the solution is unaffected by boiling, and this is called permanent hardness.
There are two ways to help control water hardness: use a packaged water softener or use a mechanical water softening unit. Packaged water softeners are chemicals that help control water hardness.
Minerals are what cause water to be hard, tap water in east coast(NJ) is harder than tap water in CA. More minerals=harder water