If you’re considering buying your own water softener, one of the questions you might have is: “what size water softener do I need?” After all, every water softener has a specific maximum capacity, which dictates how much water it can reasonably process.
If you choose a water softener that’s too small, using it regularly could lead to an increased need for maintenance and poor efficiency. If your water softener is too large, you may be overspending on something that’s too powerful for your home.
Figuring out how to size a water softener can be complex. The exact solution you need will depend on your water consumption levels, your municipal water supply, and even what kind of water softener you’re planning on buying.
What’s the Most Common Size for a Water Softener?
The ideal water softener for your needs will be large enough to ensure the system doesn’t have to regenerate too often and small enough to save you money.
Water softeners are sized according to the “grains of hardness” a system can remove in a single cycle. When determining the right product to buy, you’ll need to look at the softening capacity and the salt efficiency of the system. Around 0.7 cubic feet of resin will yield about 15,000 grains, whilst 1.5 cubic feet will give a 30,000-grain capacity.
Usually, to turn hard water into soft water, the average home will need a water softener with about one cubic foot of resin. However, there are instances where a larger capacity water softener may be required to minimise salt use and preserve the water supply.
For instance, if your water is very hard – with a hardness level of 15 grains or more – you may need to upgrade your water softener to avoid overwhelming the resin beads.
How to Choose the Right Size of Water Softener
There are a few key elements to look at before deciding what size water softener you need.
First, you’ll have to determine how much hard your water is. You can ask for information from your city water group or conduct a DIY test at home using a clear water bottle and soap. After mixing the soap and water, the bubbles will help you to determine your hardness level.
The more suds or foam in the bottle, the softer your water is likely to be. Keep in mind that some regions are known for having much higher levels of hard water than others. If the total hardness of your water is particularly high, you may need to go beyond a standard 32,000-grain water softener.
Once you’ve found out about your water quality, you’ll need to consider how much water you use. A large family is likely to use more water than a single person, meaning the right size water softener may be much larger.
You can check your water bill for information about your water usage levels. You might not be able to track daily consumption, but you can get an insight into your monthly historical water usage.
If you don’t have a water bill, multiply the number of people in your household by 75 to get an idea of how much water you’re likely to use. For instance, a 3-person household will use around 227 gallons per day.
Water Softener Size and Grain Removal
Another factor that influences the answer to the question “what size water softener do I need?” is how many grains of minerals need to be removed from your system. One grain equals around 65mg of calcium carbonate. Most industry-standard water softeners are rated according to the number of “calcium grains” they can remove.
The grain capacity of a water softener can range from 24,000 GPG to anywhere over 64,000 GPG. The smaller the number, the less hard water your system can convert. The easiest way to know the grains you need to remove for your household is to get your water tested. Testing your daily water should give you an insight into the calcium and magnesium levels in your supply.
For instance, if you have a household with three people using 225 gallons of water per day, and your hardness level is around 10 grains per gallon, you’ll need a system that removes 2,250 grains of hardness per day. Since your system will regenerate weekly, you’ll need to multiply this number by 7 to get a clear view of the grains per gallon you need. In this case, the three-person household would need a water softener with a rating of at least 15,750 GPG.
What Size Water Softener Is the Right One for You?
Based on your knowledge of your water hardness level (grains per gallon) and your water usage, you should be able to calculate the right size for your water softener. For instance, in general, a 32,000-grain water softener should be suitable for most families of 4. However, if your local water utility reveals your drinking water has a higher hardness level, you may need to increase your capacity.
While a 32,000-grain capacity water softener might seem high for a family with an average level of water hardness, it’s also worth considering salt efficiency. While a 24,000-grain softener might fit the needs of a four-person family, it will require a lot more salt for the resin bed and ion exchange process. You may also need to use a water filter to improve efficiency.
The more members you have in your family, the more you’ll need to increase your water softener capacity. For instance, if you use around 75 gallons of water per day, multiplied by 5 for the five people in your family, and you have a water hardness level of 10gpg, you’ll need to remove 26,250 GPG of grains from your system per week.
Adding on the salt usage component, you would increase this capacity slightly, often by around 10,000 grains. This would mean you’d often look for a water softener with a capacity of around 35,000 to 40,000 grains per gallon.
Can a Water Softener Be Too Big?
Depending on your water’s hardness, the regeneration cycle of your machine, and how much you use your softened water, your water softener’s capacity may need to be a lot higher than you expect. Generally, it’s best to get a water softener with a slightly larger capacity than your required one to ensure you can continue to access good water quality in any condition.
However, the right water softener won’t always be the biggest product. A water softener that’s too large for your household might not regenerate often enough. This can lead to bacterial growth in your tank and damage to the resin beads. Larger one-tank systems can also consume more water and lead to additional upfront costs.
Ideally, your water softener should be capable of reducing your hardness level to between 0-3 GPG. A water softener doesn’t have to remove every single trace of magnesium and calcium. These minerals can actually be beneficial to your diet in small doses.
Choosing the Right Size of Water Softener
So, what size water softener do you need? As you can see, there’s no one-size-fits-all answer to our initial question. Before purchasing one softening system, it’s best to research your home’s hardness value, your usage rates, and the efficiency level of each water softener available to you. In most cases, a professional will be able to offer advice on how many grains per gallon you need from the right size water softener.