Hard Water vs Soft Water? What is the Difference?

Hard Water vs Soft Water? What is the Difference?

We all just think -“Water is Water, let it be any”. But, there are many categories of water and one such is Hard water & soft water. But you give a view of differentiation parameters, you will come to know the actual difference – Hard water vs Soft water.

What is Soft Water?

Soft Water has very little mineral like calcium & magnesium in it. Another key point, most of the surface water like lake water, rainwater, river water is soft water.

What is Hard Water?

Main Features of Hard Water:

  • It is the water rich in dissolved minerals, namely Calcium & Magnesium.
  • Being rich in minerals, it owes many health benefits.
  • Toxic metal like lead & copper is less soluble.

Above all, in many industrial applications, hard water causes damage & inefficiency in work (damages in pipes and containers). This is when water softeners come into action. Also, in water softening processes, sodium ions take the place of water cations.

Important Note: Hard water is not harmful to health in general.

Hard water vs Soft water – Comparison Chart

Parameters Soft water Hard Water
Composition Rich in minerals – Calcium & Magnesium Sodium
Interaction with soap Forms a film or coating Forms froth/lather
Difficulties Faced Leaves deposits in pipes etc. leading to clogging. (known as Scaling or Film formation) None
Foam/Lather Formation No lather formation with detergent Lather/Foam is formed with detergent
Problem solved by Ion exchange process (Water Softeners) None

Differentiation: Hard Water vs Soft Water

There are many differentiation points of Hard water vs Soft water. Though hard water is rich in minerals still it gives a lot of dilemmas.

Here are a few signs which will clear the concept of Hard water vs Soft water:

  • First of all, it does not produce lather with Soap. hence, proper foam production does not occur
  • Washing hair with Hard Water leads to sticky & dull hair
  • Hard water can cause Eczema in children
  • Residues & spots on dishes
  • Clothes look dull after washing
  • Film formation on bathtubs
  • Coagulation due to Lime deposition or Scaling in pipes etc.
  • The cloudy & milky appearance of water in a swimming pool.

On the contrary, in the case of Soft water-

  • Lather formed is better with bubbles
  • No Residue on the dishes (white colored)
  • Hair becomes smooth & healthy
  • Skin becomes soft
  • Life of machines like heater, washing machine, bathroom shower etc increases.
  • Clothes get better washed & look brighter

Keeping these points in mind will help to compare Hard Water vs Soft Water.

What are the causes of Water Hardness?

Important to realize, the presence of multivalent cations in higher concentration, leads to hardness in the water. Magnesium (Mg2+) and Calcium (Ca2+) are the sources of these cations in hard water. When water flows underground, it imbibes these minerals.

What is Permanent & Temporary Hardness of Water?

When discussing Hard water vs Soft water, it is important to know about the permanent & temporary hardness of water.

Permanent Water Hardness – In this case simply boiling the water is not an effective parameter. But that does not mean it is fully permanent. In this regard, water softener helps to solve the purpose. This type of hardness is due to calcium and magnesium sulfate or chloride.

Temporary Water Hardness It is due to the presence of bicarbonate. Boiling cause carbonate formation from bicarbonate, which is then precipitated out. Hence, water becomes softer on cooling.

What is the process for Hard Water Treatment?

Here are the water softening processes-

  • By decreasing the concentrations of minerals – Calcium, magnesium.
  • Boiling it or by addition of Lime- (for treatment of temporary water hardness)
  • Ion exchange resins – (for treatment of permanent water hardness)
  • Chemicals like chelators also help to soften water.

What is the unit to measure Water Hardness?

The unit of water hardness is “grains per gallon” or “grains of hardness”.

One grain is equal to 64.799 (64.8) milligrams.

Here is the equation to convert grains per gallon (gpg) to mg/liter-

Mg/L = gpg times 17.1

One grain of Hardness = 17.1 milligrams per liter

There are many instruments which measure contaminants dissolved in water in the units “parts per millions” ppm. It is the ratio of the weight of insoluble contaminants to the ratio of the weight of the water.

  • Parts per million is the same as milligram per liter (as water weighs one gram per liter)

The measure parts per million (ppm) is also used as grain per gallons (gpg). Both ppm & gpg are different units, measuring the same thing.

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