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How Hard Is “Hard”?

Soft water

Less than one GPG

Slightly hard

1-3.5 GPG

Moderately hard

3.5-7 GPG


7-10.5 GPG

Very hard

10.5 or more GPG

*One GPG is equal to 17.1 PPM

Hard water is the most common residential water problem in the United States. The issue occurs naturally when minerals like calcium and magnesium dissolve into your water supply. Hardness is measured in grains per gallon (GPG), which is a unit of weight equal to 1/7000th of a pound, or in parts per million (PPM). Any water that contains dissolved hardness minerals above 1 GPG or 17.1 PPM is considered hard.

Hard water is generally not harmful to your health, and it is perfectly appropriate to use around the house for activities such as watering a garden, general lawn care, and washing your car, so why is it important to soften it inside the home?

The issues caused by using hard water are more subtle than direct health problems, but they can have a substantial effect on your free time, the taste of your food, and your bottom line.

Why You Need Soft Water

When soap reacts with hard water, the result is a white precipitate known as “soap scum” instead of the frothy lather used to effectively clean your dishes, clothes, and skin. waterstains Waterstains on a bath faucet. Soap scum leaves unsightly blemishes on your glassware as well as a thick layer of limescale across bathtubs and showers. Bathing in hard water makes skin dry, itchy, and irritated.

Over time, this same build-up of scum begins to clog your plumbing and diminish the efficiency of your water heater, eventually necessitating expensive replacement costs. Additionally, hardness minerals can cloud your ice cubes and contribute to unwanted tastes in cooked foods such as vegetables and pastas.

Anyone who has ever had to hide their cloudy drinking glasses from guests or spent hours scrubbing stubborn stains in the bathroom understands the difficulties of living with hard water. By contrast, an effective water softener will save you money on clothes, dishes, soap and other cleaning agents, and electricity bills.

How Water Softening Works

The most common way to soften water involves an ion exchange process to replace hardness minerals in the water with another substance, such as sodium. Typically, water softeners are filled with beads of resin. Each bead of resin contains a slight electric charge which binds sodium ions to its surface.  As hard water pours into the softener, it flows through the resin beads. The hardness minerals in the water have a stronger attraction to the beads than the sodium. Therefore, they attach themselves to the beads and displace the sodium ions. This is why the process is known as an ion exchange.

Eventually, the resin is coated in hardness ions and can no longer effectively soften the water.  At this point, the softener will begin its “regeneration” cycle to cleanse the resin. In regeneration, a brine solution featuring an extreme concentration of sodium ions is delivered from the brine tank to the softener. The salty brine reverses the ion exchange process to scrub the hardness from the resin before being flushed away, leaving the softener once again ready to remove calcium and magnesium ions from hard water.

While the market offers other softening options such as chemical treatment and magnetic water softening, these methods range from significantly less effective to downright useless. Tried and true mechanical water softeners are the best performing, longest lasting softeners available. Recent advances in technology have greatly reduced the amount of electricity and sodium used by modern water softeners, and a high quality softener should be an essential part of any modern home.