Difference Between Hard Water and Soft Water

Hard Water Vs Soft Water

Hard Water and Soft Water are the two terminologies generally used for classifying the types of water. You must be thinking, plain water is always crystal clear then how can one say it is hard or soft water.

The nature of water whether it is hard or soft is classified on the basis of the presence of the concentration of minerals (calcium and magnesium) in the water.

Hard Water

Water that has a high content of dissolved minerals such as calcium and magnesium sometimes iron too is known as hard water. Generally, if a liter of water has around 60 milligrams of mineral concentration in it then it is regarded as hard water. With the increase in mineral concentration per liter the level of hardness of water also increases.

Soft Water

Water that has a low or negligible amount of dissolved calcium or magnesium in it is called soft water. In a liter of water if the concentration of carbonates of calcium or magnesium is less than 60 milligrams then such water is regarded as soft water.

hard water vs soft water

Difference Between Hard and Soft Water

Mineral Constituents

The basic factor that differentiates hard water from soft water is the quantity of mineral constituents presents within it. Hard water specifically contains a higher amount of calcium and magnesium. Whereas, unlike hard water, soft water does not have a high concentration of calcium or magnesium rather such water contains a high amount of sodium ions or salt.

When reacts with Soap

When hard water reacts with soap then it does not produce lather. While soft water forms lather when it is reacted with soap or detergent.

Which is beneficial for health?

Hard water is comparatively healthier to drink than soft water. Basically, the presence of a high amount of minerals in hard water makes it suitable for drinking as it makes a contribution to the dietary requirement of essential minerals in our body. On the other side, low or almost negligible minerals are present in soft water thus, it is not regarded to possess that much healthy nature.


On visually noticing both hard water and soft water appears to be the same i.e., plane and transparent. However, the taste of the two types of water is quite different. Hard water has a somewhat better taste than soft water because the presence of sodium ions in soft water makes it salty in taste. While hard water has a characteristic taste (tasteless or sometimes little sweet).

Boiling Point

The boiling point of these two types of water is also different. Hard water has a high boiling point in comparison to soft water. Thus, hard water when used for the purpose of cooking consumes comparatively more amount of fuel than soft water of the same quantity.

Ease of Cleaning

When hard water reacts with soap it forms soap scum rather than forming lather. Whereas, soft water when reacts with soap produces leather. Due to this reason, it becomes difficult to clean soaps using hard water.

Effects on Skin, Hair, and Clothes

In terms of cleaning benefits, soft water is more advantageous than hard water because the former cleanses out soap easily. Thus, the former puts harmless effects on skin and hair. On the other side, hard water is quite harmful to skin and hair as the residual soap on the skin after bathing in hard water traps bacteria resulting in disturbing the normal pH balance, thereby drying the skin.

Fading or Water Spots

When hard water reacts with the surface of a material, then it results in limescale deposits on the surface while this is not the case with soft water. Due to this reason water spots in utensils, or windows are left behind in case when hard water is used.

Efficiency towards Appliances

When any electrical appliance like a water heater is used then their amount of energy usage depends on the type of water it is using. Appliances that use hard water consume more power than soft water. Also, the equipment that makes use of soft water possesses longer life of about 30% to 50% than the ones that use hard water.


Generally, the use of hard water leads to the chances of galvanic corrosion which takes place when electrolytes of hard water react with other metallic surfaces. As against, this is not the case with soft water. Thus, by observing the metallic surfaces which come in contact with water on a regular basis one can say whether the water is of hard nature or soft. If the surface is getting pale yellow or becomes dull then the water is hard otherwise it is soft.

Quick Comparison: Hard Vs Soft Water

BasisHard WaterSoft Water
Mineral contentHighLow
ConstituentsMagnesium and Calcium ionsSalt or sodium ions
Reaction with soapDo not form lather rather forms grayish scum.Healthy lather is formed.
Boiling pointHigh Low
TasteCharacteristic taste (i.e., tasteless) Salty
Limescale depositsPresentNot present
Health benefitsMoreComparatively less
Effect on clothes, skin and hairHarmfulHarmless
Energy usageMoreLess
Corrosive natureIts use corrode the material.Its use does not corrode materials.
How to recognize?Surfaces with continuous contact with hard water turns out pale yellow (showing scale deposit).Surfaces with continuous exposure to soft water remains as it is.

Rainwater is considered to be one of the best examples of soft water. But it reacts with minerals like lime, calcium, and magnesium on its way towards the ground. Thus, becomes hard.

In order to get soft water from hard water, there are water softening schemes that are to be utilized. For softening a small quantity of water that is moderately hard, boiling of water or using vinegar helps in the removal of minerals. However, sometimes hard water is passed through ion exchange resins which are nothing but complex sodium salts.  When water flows through it, sodium gets dissolved in water leading to the precipitation of minerals on the resin surface.

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