Hard Water vs Soft Water Explained: What’s the Difference?

Although we may often think that water is simply water, there are actually two types: “hard water” and “soft water”. With more than 85% of the US having hard water, there’s a fairly good chance you might have experienced it. So, before we get into any of the details, what really is the difference between hard vs soft water, and how do they affect you?

What is hard water?

Put simply, the hard water is determined by the amount of dissolved minerals like calcium and magnesium contained in the water itself.

The higher the content of these minerals, the harder the water.

The hardness of water is measured and calculated in grains of hardness per gallon of water, or as parts per million or milligrams per liter. Water hardness is reported to be a problem for daily use when the concentrations of calcium carbonate and magnesium exceed 6-7 grains per-gallon .

How is Hard Water Measured
HardnessGrains per Gallon (GPG)Parts per Million (PPM) & mg/L
Soft<1 0 – 17
Slightly Hard1.5 – 517 – 60
Moderately Hard3.5 – 7 60 – 120
Hard7 – 10120 – 180
Very Hard>10>180

Benefits of Hard Water

  • Full of minerals essential for good bodily function
  • Safe to drink and often tastes better
  • Reduces risk of kidney stones & hypertension
  • Magnesium help prevent heart disease

Hard water can be seen as preferable as drinking water due to the fact that mineral content in hard water provides nutritional value that humans need.

As calcium and magnesium are two essential minerals to humans, their presence is a desirable benefit of drinking hard water. Not getting enough of either mineral and lead to increased risk of osteoporosis, kidney stones, hypertension, and a number of other conditions and diseases.

Disadvantages of Hard Water

  • Limescale buildup on appliances
  • Clothes don’t get fully clean
  • Water spots left on dishes and faucets
  • Hard water may cause appliances to be less efficient
  • Soap scum buildup in showers and bathtubs
  • Exacerbates eczema symptoms and dry skin

The dissolved minerals in hard water cause a plethora of issues, ranging from health effects like skin and hair irritation, to more mundane problems like clothes not getting fully cleaned, water spots on dishes, scale buildup, and staining in bathtubs and sinks. Many of these problems are caused because soap is prevented from lathering well by the calcium and magnesium minerals in the water, reducing its ability to clean clothes and surfaces. The issue of scale buildup poses a bigger risk of increase maintenance costs and even shorter lifespans for your appliances which use water.

hard water stains
Hard water spots

What is soft water?

Water in its ‘pure’ form though, as fresh rainwater, is naturally soft. It is the journey the water takes once it reaches the ground that changes its structure.

To return hard water to its soft state, water softening systems are employed to reduce the concentrations of minerals, leaving only sodium ions and water soft. This makes things like washing dishes, cleaning your shower head, and washing clothes a lot easier as soft water doesn’t leave soap scum or mineral stains.

Benefits of Soft Water

  • Increased efficiency of appliances
  • Moisturized hair and skin
  • Cleans clothes more thoroughly
  • No residue buildup in sinks, bathtubs or showers
  • Spot-free, clean dishes

When water is soft it promotes the lathering agents in soap, and improves rinsing efficiency and has a moisturizing effect on the skin and hair.

Similarly, using soft water to wash clothes and dishes allows the water to dry without leaving water spots and does not promote discoloration of clothes in the wash because it does not leave a mineral residue. However, the most prominent effect is that it doesn’t slow down and shorten the lives of your appliances by leaving scale buildup.

Related: Wondering if Soft Water is OK to Drink?

hard water vs soft water comparison chart

How to Deal With Hard Water?

The first reaction to unwanted hard water is “great, well how do we fix it?

Water softeners are systems that turn hard water to soft water using various methods. Luckily, there are several options to treat water hardness which we’ve outlined below.

Salt-based Water Softener Systems

These types of water softeners work by passing water through what is called a resin bed, using the ion exchange process to replace hard mineral ions with sodium ions, resulting in soft water. These systems have a resin tank and a brine tank, the resin tank containing the resin beads to remove the hard water minerals, and the brine tank storing the salt. Salt-based systems are the most effective solution, as they completely eliminate calcium and magnesium from water.

Electronic Descalers

These systems address hard water problems without the use of salt. They create a magnetic field when connected to your pipes, and when water passes through the hard water minerals are altered so that they no longer are able to stick to surfaces. This reduces scale buildup but does not remove the minerals from water like a salt-based system would.

Related: Read about the difference between descalers and water softeners

Template Assisted Crystallization (TAC)

Another salt-free water softening process is something called Template Assisted Crystallization, or TAC. The hardness minerals in are converted to a crystal that is not able to bind to surfaces. While this is actually a process of water conditioning, not softening, the results are comparable seeing as the minerals and impurities can still strained out from the water source.

Wrapping Up

It is a general consensus that soft water is typically preferred for residential households and businesses alike.

While water softening systems cost money upfront, their installation can save you thousands in repairs and replacements of appliances down the road, not to mention the soft water contributing to the extended life of your clothes, an increased health of your skin and hair, and the lack of waste in cleaning products.

If you are thinking about softening your water, its best to speak with a professional about how a system might affect your plumbing, as well as to understand the ins and outs of associated maintenance.