How to Properly Size a Water Softener For Your Home

Many online and in-store tools designed to help consumers pick the right sized water softener overlook the concept of softener salt efficiency, leading to selections that may be properly sized but are inefficient, resulting in excessive salt consumption and environmental impact.

Why Should You Care About Efficiency?

Efficiency dictates the amount of salt needed, impacting cost, environmental discharge, and ease of ownership. An efficient softener uses minimal salt, translating to significant savings and less environmental impact over its lifespan.

Calculating Daily Softening Requirement

To properly size your water softener, the first step is to calculate the daily softening requirement, which is a measure of how much hardness the softener will have to remove daily. This requires knowledge of your water hardness and daily water consumption.

Understanding Water Hardness

Water hardness, measured in mg/L or GPG, indicates the amount of calcium and magnesium in your water. Knowing this value is crucial as guessing can result in an improperly sized system. Additionally, the presence of iron in the water requires a correction in the total hardness value.

Estimating Water Consumption

Your household’s water consumption is a vital factor in calculating the daily softening requirement. This can be accurately estimated from water bills or by multiplying the number of people in the household by 75 gallons per day.

Matching Softener to Conditions

After determining the Daily Softening Requirement, a water softener is typically sized to regenerate about once per week. However, misinformation online can lead to choosing a system that appears ideal but requires excessive salt for regeneration, impacting both cost and environment.

Calculating the Daily Softening Requirement

Calculating an accurate estimate for your daily softening requirement is an important step in properly using water softener for your home. This can be done on your own or with the help of a professional.

To do this, multiply your daily water use by your water hardness (corrected for iron). This number is your Daily Softening Requirement.

Here's an example:

Hardness: Measured at 10 grains per gallon.

Daily Water Use: 4 People X 75 Gallons per day = 300 gallons per day.

Daily Softening Requirement = 10 grains per gallon X 300 gallons per day = 3,000 grains per day.

Selecting a Softener to Match Your Conditions

After determining your daily softening needs based on local water conditions and usage, it's time to select the right water softener. Softeners typically regenerate once a week to balance maintaining the resin bed and avoiding excessive wear on the valve, which only moves during regeneration. This schedule also helps in conserving water, with a softener using about 50 gallons per regeneration.

For a daily requirement of 3000 grains, you’ll need a softener that can handle 21,000 grains weekly. However, choosing the right model can be tricky due to misleading information online and in stores.

Many available models, like the ones with 24,000 or 32,000-grain capacities, might seem suitable at first. But it’s essential to look beyond the numbers. For instance, a 24,000-grain system actually requires a substantial 27 pounds of salt for regeneration and is more accurately described by its resin amount, which is "0.75 cubic feet."

Similarly, what’s commonly marketed as a "32,000" grain system is more accurately a "1 cubic foot" system, which would require 36 pounds of salt for full capacity. Interestingly, using just 6 pounds of salt on a one cubic foot system still yields 20,000 grains of capacity. Opting for this unit, despite the slightly higher upfront cost, results in notable salt savings, making it more economical and environmentally friendly in the long run.