What Size Grain Water Softener Do I Need?

September 27, 2016

I always thought water came in one of two ways: salt or drinking. You drank the pure and sunbathed by the rest. Right?

Wrong. Your household water supply – what you cook, clean and bathe in – can either be hard or soft. Hard water is full of minerals like calcium and magnesium, which basically negates any cleaning done with it. It leaves your laundry dingy, glasses splotchy, and shower walls, dishes, and appliances coated with a film.

Luckily, a water softener can solve all of your hard water problems. Each system comes with a different set of features, customized to your household’s needs.

So when picking out your device, consider this first questions: How many grain water softener do you need and what size water softener do I need?

How Many Grain Water Softener do You Need?

Water Hardness

First off, water is measured in “grains.” The softest water ranges from 0-1.0 GPG (grains per gallon) and the very hardest can be anywhere above 10.5 GPG. Note: A “grain” is equivalent to 1/7000th of a pound.

You can measure water hardness with a testing kit or, if you’re on city water, the hardness level can be found online in your local water utility’s annual reports.

Water Consumption

Next, consider how much water is used in your household. The average person uses about 75 gallons a day, so multiply 75 by the number of people in your home. That may seem like a lot, but think about every shower, a load of laundry and toilet flush—it adds up.

Grain Capacity

Once you’ve figured out the daily water consumption, the last step is to multiply that amount by the grains of hardness in your water. The final total will be the “grain capacity,” which is the number of grains that need to be removed daily to keep your water soft. A higher grain capacity means a larger water softener.

I realize this could be a lot to swallow at once, so let me break it down for you with a hypothetical.

4 people in the house X 75 gallons of water X 150 grains = 45,000 grains that need to be removed per day, or “GPD.”

Most water softeners regenerate or clean out their resin bed, about once every seven days. The resin bed inside the system becomes coated with hard water particles, so it must recycle the water used so it can continue to produce quality water. It’s important you purchase an appropriately sized water softener to avoid regenerating too often and wasting money, or not regenerating enough and the system wearing down quickly.

Keeping your water clean is important to keeping your household safe. If you have any questions about devices or water hardness, contact a professional to match you with the perfect sized water softener you need for your home.

Trusted by San Antonio Companies and Homes

Kinetico Water Softeners are rated 4.9 out of 5 from 628 reviews.

Jonathan Myers

We're very glad we got this installed. The technician, Alberto, was very polite and thoroughly explained what he was doing and what we would need to do.

Kyle James

Alberto kept me informed on his arrival time. He was professional and exceeded my expectations concerning the install of the water filtration system. I also need to put a plug in for Tracy for her patience and skills at making things happen behind the scenes...a true unsung hero. They both deserve a raise!


I just had my system installed by Alberto and Jay, and I wanted to say that they rocked. Got it all in and gave me some instructions to follow, all while being determined to detail and professional. Thanks, fellas.