A water softener can be an excellent addition to any home. However, figuring out how to size a water softener is often easier said than done. Despite the number of water softener buying guides on the market, it can be incredibly difficult to understand what you should actually be looking for when you’re searching for something to suit your family.
The good news is that we’ve put together this guide to provide you with everything you need to know about sizing a water softener. Here, you’ll learn how to answer the question, “what size water softener do I need?”. By the time you’re done reading, you’ll understand the concept of grains per gallon, how to calculate your daily water consumption, and even what kind of impact water hardness has on your water softener size.
What Is a Water Softener?
A water softener is a mechanism that can help to remove some of the excess hardness in your water by filtering out certain products like calcium. Softening your water can change its taste, and also protect your appliances and pipework from damage.
Water Softener Setting, Hardness, and Sizing
One of the first things that you’ll need to evaluate when conducting proper water softener sizing is your water hardness. This basically highlights how much magnesium and calcium is dissolved in the water that you get in your home. Depending on where you live, this information will usually be given in the form of grains per gallon. Grains per gallon is the industry-standard measurement for discussing water hardness. Most water softeners will come with a gallon rating.
What Does 30000 Grain Capacity Mean?
If you’ve been shopping for water softeners for a little while now, then you may have seen things like “32,000 grain” or “48,000 grain” per gallon ratings on your water softeners. This implies how much water hardness your water softener can withstand. Crucially, the mg/L gallons per grain measuring on a water softener can be dependent on how much salt you use in your system and various other components, too.
Look at the annual reports from your city on the water hardness in your region. You can usually find this information online. Remember, when iron is present in your water, you’ll have to correct the hardness value. For every 1.0 mg/L of iron, you’ll have to add 3 gallons per grains to the hardness value.
What Size Water Softener for Family of 3 Is Suitable?
When answering the question “how big of a water softener do I need?”, one of the most important things to consider is your average water use. You’ll have to think about how much water is consumed in your house per person. Hence, the number of people in your household will make a significant impact on the appropriate size of water softener for your home.
The most common way to measure a water softener is to multiply the number of people in your home by around 75 gallons per day. So if you’re wondering what size water softener for family of 4 is recommended, you’d need something capable of managing at least 300 gallons.
It’s also worth noting how many places your family can use water simultaneously. You could have two sinks running, bathtubs filling, and toilet flushing all at the same time. Your flow rate will be measured at gallons per minute. A well-engineered system will be able to deal with significant use from all members of your family. This is another important thing to remember when learning how to size a water softener.
For those with larger families, you might still be asking “what grain water softener do I need?” While the average domestic water use usually stands at around 75 gallons per day, you might want to account for a higher consumption if your household uses more for 7 days regularly. Consider upgrading to 100 gallons per day or more for each user.
Water Quality and System Capacity
Aside from focusing on the question “what size water softener do I need?”, you’ll also have to look into the water quality in your home and the capacity of your potential water softener. Water softeners can remove various substances from your water, including magnesium and iron. When sizing your softener, think about all the minerals that your water softener will have to contend with.
In some cases, it may be more efficient to use an iron filter for removing iron and manganese from water instead of a softener device. Keep this in mind when you’re considering things like your grains per day and the softener’s capacity.
The system capacity of your water softener will also play a part in your decision. Water softener machines come with ion exchange resin beads inside of them. These beads remove hard minerals by withdrawing them from the water. A softener’s capacity is based on the amount of resin in the unit. Most devices come in systems up to 2.0 cubic feet in length. However, once a system has reached its capacity, the resin beads will be incapable of softening the water.
You should add around 30% extra allowance on top of your calculated grain capacity to make sure that you don’t run out of performance between regenerations.
Speaking of which, it’s also worth making sure that you know how frequently you will need to regenerate your water softener. These mechanisms require regular backwashing when the ion beads are fully used up. Metered water softening systems can measure your consumption and try to regenerate frequently enough to keep up with your needs. However, the excess load on the softener can reduce the life of the mechanical components in your system.
A good size of water softener should be able to last at least 4 days between regeneration.
Calculating Your Water Softener Requirements
There are a number of points to consider when calculating your ideal water softener measurement. Your softener hardness settings and grains capacity will make a huge difference in how long your system can run without regeneration. The more grains per day it can handle, the easier it will be to keep your system running smoothly.
However, even with a system that can manage a large grains capacity, you should still consider the number of people, the overall hardness of your water, and how frequently the grains are going to be refreshed. Some families might require at least 1000 grain capacity per person. Others will want something much smaller, falling under the 1000 grain benchmark.
Here’s an example of how you might calculate a grains requirement in a household with a lot of water use, extremely high hardness, and a very demanding flow rate capacity per person.
• Flow requirement: 10 gallons each minute based on a washing machine, dishwasher, and two sinks split over 8 days
• Volume requirement: At least 400 grains each gallon per day. Measuring for 100 grains per person.
• Water quality: About 25 grains each gallon for total hardness.
400 gallons multiplied by 25 grains per day equals at least 10,000 grain per day. Since you want that system to last for at least four days, multiply the 10,000 grain per day load by 4. This means that you’d need a 40,000 grain unit. Since you want a little bit of leeway for your softener, you’d probably add a 10,000 grain reserve at least. This means that you’d be able to get either a 48,000 grain unit – which is common for 1.5 feet options, or a 64,000 grain unit. That’s usually what you would get in a 2 cubic feet product. Anything under 48,000 grain would require too much work to maintain.
Can Your Water Softener Be Too Big?
Since it can be difficult to ensure that you have the right grains per gallon, even with a massive 64,000 grain unit, you might be wondering whether you could ever have a machine that’s too big. Instead of worrying about “how many grain water softener do I need?”, you might consider buying the biggest option around.
However, if you get a 64,000 grain device when you only require a 58,000 grain unit, your system might regenerate too infrequently. What could’ve been more than 7 days cycle, might become shorter. This could lead to resin damage within your softener. Moreover, if your 58,000 grain solution is too big for your home and your water softener hardness settings, then you could risk an inefficient system.
An inefficient 64,000 grain system would increase the amount of salt that you have to buy to keep your device working properly. It would also mean that you’re working harder than you want to in order to remove the hardness and grains from your water each day.
Are You Making the Right choice?
Figuring out how to size a water softener can be tough. Only you can decide how many grains your system needs to run efficiently.
Evaluating your household requirements will help you to make the right choice when asking “what size water softener do I need?”. Most large 4-person families that use a lot of water will need at least 48,000 grain units. However, your home could require a bigger grains capacity than this or fewer grains, depending on how you live.
