How To Size A Water Softener: Basic math to determine how large your softening system needs to be

When it comes to sizing a water softener, choosing the right size for your water use is very vital. Water softeners vary in sizes with each size, stating how many hardness it can remove from water before regeneration. If you choose a small-sized softener, it will soon exhaust its capacity, decrease water pressure, and affect flow rate.

Choosing a softener that is too large, on the other hand, will result to inconsistent regeneration. Either way, it will cost you more money to maintain it and keep it working at an optimum level. That is why properly sizing a water softener is essential. This article will teach you what you need to understand about how to size a water softener.

Despite the different sizes of water softener flooding the internet, the issue of incorporating water efficiency hasn’t been thoroughly factored. A vast majority of water softeners have a massive salt consumption of more than 2000 pounds a year, against highly efficient models that uses 300 pounds over the same year.

The size of a water softener is determined by gallons per day (GPD) - how much it needs to filter in one day. There are three main methods for sizing a water softener: GPD, grains per gallon (GPG), or an equal number of people served in one hour.

A water softener is a device that removes calcium and magnesium from hard, untreated water. If you're not sure what size of water softener to buy, here are the three main factors to consider:

  • Your household's daily total number of person-days-of-water usage
  • The amount of water your household uses per day
  • Your household's hardness level

A few other things to consider before purchasing a water softener:

Is there anything that needs to be considered? (such as kidney disease) Do you wish to use softened water for laundry? Do you want the softened water only for drinking or cooking as well?


Table of Contents

What is a water softener?

A water softener is a filtration system that removes excess calcium and magnesium minerals in the water. These calcium and magnesium minerals are responsible for water hardness.

What Is A Water Softener

Hard water is detrimental to livelihood. It makes modern homes uncomfortable and unsafe. It destroys the lifespan of some home appliances, like coffee makers, dishwashers, hot water appliances, etc.

They build up as deposits in pipes and decrease water pressure. Once the temperature of your heater rises, the deposits of minerals will solidify and expand, making a cracking noise in your water tanks.

Hard water makes the laundry a living hell. You will need a whole lot of extra detergent before the water can foam. It doesn’t form lather with soap and bathing in hard water will leave your skin dry and itchy.

Hard water will also leave filmy soap scums in your bathrooms, kitchen, etc. A water softener is the only solution to water hardness as it will remove these minerals, causing water hardness through ion exchange.

Why Should I Care About Efficiency?

Why Should I Care About Efficiency

You should care about the efficiency of your water softener because it dictates how much salt you have to purchase, the quantity of salt you have to add, and how much salt that gets discharged to the environment.

Factoring a softener salt’s efficiency when sizing a softener will ensure that you purchase a softener that uses a minimal amount of salt. This goes a long way in cutting down costs and saving more.

Why should you care about sizing a water softener?

Here are some tips for choosing the right size water softener for your home or considering it.

First of all, let's talk about what a water softener does. Water softeners filter out hard minerals from water. This results in purified, softened water. The purpose of the water softener is to make it easier for you and your family to drink.

Hard minerals can be very hard on your plumbing, decreasing water flow and causing clogs. Softened water is great for all the plumbing in your home. It also provides better taste, cleanliness, and health benefits to everyone who drinks it. Water softeners come in various sizes and costs, depending on the water needs of your home.

One question you may ask is how large my softener should be? That depends on what size your family is and how much water they will use. You will learn in this article what you need to know about water softeners and what size you might need.

Undersized and oversized problems

The undersized and oversized problems are not always easy to spot. One may notice that the problem is undersized but not realize it is oversized until it has caused more damage than usual.

How To Properly Size a Water Softener?

How To Properly Size a Water Softener

The key to properly sizing a water softener is by, first of all, identifying your water quality, use, and making sure it concurs with the size of your water softener to bring about effective soft water capacity. Five steps are involved in sizing a water softener properly. They include;

Determining your water hardness level

Like explained, hard water is water that has a high concentration of calcium and magnesium ions in it. If you can’t determine your water’s hardness level, it will result in improper sizing.

Determining Your Water Hardness Level

Water is generally classified as soft water, moderately hard water, or hard water, depending on the amount of calcium and magnesium ions in it. These amounts are measured in milligrams per Litre (mg/L), parts per million (ppm), or grains per gallon (gpg). The table below represents the water hardness chart; 

Water level

mg/L

gpg

Soft

0-60

0-3.5

Moderately hard

61-120

3.56-7.01

Hard

121-180

7.06-10.51

These measurements determine the hardness of your water, which is essential in properly sizing a water softener.

You can determine the level of water hardness by buying test kits online or having someone test your water in the laboratory. If you use city water, you can determine the hardness level from your local water provider as an alternative. They usually publish their annual reports online.

Estimating your daily water consumption

Estimating Your Daily Water Consumption

Determining the quantity of water you use every day is the second step in this list. If you don’t want to be racking your brain and, in the end, miscalculate the result, check your water bills. It shows your total water consumption over a period.

If you don’t have the luxury of accessing such information, you can calculate your average daily water use by multiplying the number of people using the water in your home by 80 (for regular users) or 100 (for extreme users). This will give you an estimated daily water consumption.

For example, if it’s a 2-person family, multiply 80 x 2, which equals 160 gallons of water consumed daily.

Calculating your daily softening requirement

Calculating Your Daily Softening Requirement

Now that you know your estimated daily water use, next is to calculate the daily softening requirement. Multiply your everyday water use by the number of hardness in the water. Hardness is 10 grains per gallon, which means that if your daily water consumption is 160 gallons, your water softener will be removing about 1600 grains daily.

First, decide how many gallons of water you use each day. Calculate how much water hardness is acceptable for your household based on your daily usage.

It is possible to find out how many gallons of water you use each day in a few different ways. One way is to take the size of your water heater and divide the gallons per minute by the size of your water heater. Another way is to use a gallon meter device that measures how much water is used in the household each day.

To calculate your daily usage, multiply the size of your water heater by the gallons per minute. For instance, if your tank holds 40 gallons and you can fill it in 3 minutes, you use 120 gallons per minute. This is not an average since the meter only fills up at 60 gallons per minute, so your daily usage would be 120/60 or 2.5 times more than what you expect to use.

  • An easy way to figure out how large of a softener you need is to take the size of your water heater and divide it by 2 (round down). This will give you the ideal size for your softening system.
  • For every 5 people in the house, you'll need to add 2 extra pounds of resin (for example, 10 ppl=2 lbs, 15 ppl=3 lbs, 20 ppl=4 lbs).
  • You'll need to add a few pounds if you have any water features in the yard, such as a fountain or pond.
  • No. If you have any appliance that uses water on-demand (meaning they run cold/hot as needed), you will need to add some extra pounds to the budget.
  • You need to add a few extra pounds if you have any hot tubs or Jacuzzis.#. A typical system can handle about 40,000 gallons per month. If your household uses more than this amount, you will need to add extra resin and/or salt.
  • You'll want to consider adding some capacity for future growth in the family or if you plan to add a water feature such as a fountain or pond.
  • You need to consider how much extra space is required for the softener and filter, typically placed in a utility closet or basement.
  • Older homes may not have the plumbing to handle larger water softeners, which can clog up the plumbing and be very costly to fix.
  • The most common sizes of water softeners are:
  • 1/2 pound per day units are the smallest and best for a house with one or two people. You can add extra capacity if you have more than this amount, but it is less efficient.
  • 1 pound per day units are the most popular. They provide added value for households with two or more people doing laundry and using a dishwasher weekly.
  • 2 or 3 pounds per day units are for larger households with very large amounts of laundry and dishwasher use. Water softeners can handle high usage, but it's more economical to size them for average usage.

Calculating your required total grain capacity

Regeneration is the process of washing and draining away minerals that have accumulated in the resin bed with either sodium or potassium. A water softener is only able to remove as many as hardness grains as possible before it regenerates.

Calculating Your Required Total Grain Capacity

As the softening undergoes, the resin beds inside the tanks will likely get saturated. It may not get saturated immediately, but it will, at some point. And when it does get saturated, removing calcium and magnesium ions will be limited or restricted.

Usually, a water softener is sized to regenerate about once in every week. Most experts advise this to improve high softening efficiency, protect the head valve against wear, and also conserve the resin bed, ensuring it is safe from iron and sediment.

Your total grain capacity is determined by multiplying your hardness grains by seven days. In this case, it is 1600 grains x 7, which equals 11,200 full-grain capacity per week.

Considering salt efficiency

Considering Salt Efficiency

From calculations, a water softener can regenerate about 11,200-grain capacity in a week without having to run out of water. However, this is still mere estimates because we haven’t factored in salt efficiency or brine efficiency as it’s called sometimes.

This is the trick to all this - most people are unaware that partial regeneration is more efficient and less costly than full recovery. That is because regenerating a resin bed to 100 percent will take up a large amount of salt, which is a little on the high side. And if a resin bed isn’t regenerating to 100%, it will likely to exhaust faster.

Take, for instance - a 15,000-grain capacity system would be ideal for you since you want to remove 11,200 hardness grains from water. What you do not know is it will take about 20 pounds of salt to regenerate the system to 100%, which is massive. It will take about 24 pounds of salt to fully regenerate a 24,000-grain water softener capacity system to 100%, which is still on the high side.

However, if you regenerate about 45% of the resin beds, it will take less amount of salt when you compare it to regenerating about 88%. What this means is since you have 11,200 hardness grains per week, you should choose a higher grain capacity of 33,000 and above. 45% of 33,000-grain capacity represents about 14,850 hardness grains, which means you have regenerated 11,200 hardness grains to 100% with less amount of salt and less exhaustion.

A 33,000-grain capacity removing 11,200 hardness grains is more efficient than a 15,000-grain capacity removing 11,200 hardness grains because of it’s of bigger capacity. It will result in fewer costs on salts in the long run and less salt discharge, which affects efficiency.

Considering flow rates

A water softener is as good as its softening capacity. However, you can’t expect your water softener to deliver soft water into the entire house all the time at an optimum level. Sometimes, you may experience hard water that may leak through. This may not be surprising, but when it does leak through, the results will likely be a decrease in pressure and flow.

Considering Flow Rates

For instance, this incident often happens in the morning, where there is a rush to meet work and school schedules. Different showers will be on; taps will be running simultaneously, there will be a lot of dishwashing in the kitchen, and so on.

So, you need to pay close attention and observe your water carefully flow rates. The usual standard for measuring flow rates in gallons per minute or GPM for short. Large homes do require higher flow rates than small homes.

In that case, families should get systems that will provide gpm that will be sufficient. We advise that large families should use a minimum of 15 gallons per minute, while small families should use less.

Available tank sizes and capacities

Tank sizes and capacities are usually measured in gallons, but the most common unit is liters. Three and a half liters equal one gallon. Tanks can be any size or capacity so long as the total volume is less than or equal to 10,000 gallons. A tank is installed in a building for use by heating and cooling equipment.

Tanks are usually measured in gallons, but the most common unit is liters. 3.78 liters make up one gallon. Tanks can be any size or capacity so long as the total volume is less than or equal to 10,000 gallons. A tank is installed in a building for use by heating and cooling equipment.

Your water usage

Your water usage is something you might not think about much in your average day, but it's a big part for what we do. We all need to water our plants, wash the dishes, and drink the water, but we need to monitor how much we consume.

It's easy to overlook the fact that we're using a resource and not letting it go down the drain.

To make sure that you're using water wisely, it's important to take time to think about how much you use and what you can do to cut back.

Sizing Commercial Softeners

Make sure you know how big your softener is when you are buying it. In 24 hours, the "largest capacity" refers to the water that your softener can handle. Maximum daily demand is the amount of water that your softener can handle in 24 hours. The maximum capacity is generally 10% higher than the most daily demand as a rule of thumb.

Water Softner Calculator

A water softener size calculator is a way of calculating the ideal size of your water softener, based on a variety of parameters like water conditions, water consumptions, required total capacity of regeneration, and softening requirement.

Why should I buy an efficient water softener?

For the world of Waterloo, it is thought that 134,723 household water softeners use about 2.7 billion liters of water and 44,700 tons of salt for softener regeneration per year.

It is same as more than 10 Olympic sized swimming pools having full of water, and 1/3 of the weight of CN Tower in salt.

Dissolved chloride and sodium ions end up drinking water supply and the Grand River supply. To use water for resin, regeneration is the wastage of water resources.

This may seem the flushing money down of the drain; it also affects the quality of water. A good type of water softener costs as much as 400 dollars a year in salt and water to operate.

The average requirement initiated softener at present in the market would cost three people household about 200 dollars a year to do work.

The exact water softener uses less water and less salt. It is good for the wallet, our community, and the environment.

How to choose the right water softener

The best way to choose the right water softener is to identify what you need. Selecting a water softener based on your budget and needs will narrow your options. If you have very hard water, a whole-house system may be the best option for your home because it softens all the water in your home and provides consistent results.

However, if you plan to change the filters regularly and have a small household, an under-sink water softener may suffice. When choosing the right water softener, you also need to consider your budget.

Because of the plumbing involved, a whole-house system will cost more than an under-sink one. However, undersink systems are more affordable since you don't need to hire an installer. Do the math first by finding out how much water your household uses per day. This number will help you determine the right size of softener to get for your home.

How to size a commercial water softener?

To determine the size of a commercial water softener, use gallons or liters rather than pounds per day. A 100-gallon commercial water softener can filter up to 100,000 gallons of water a day. Softeners are sized according to how many people use it and what their water consumption habits are.

Water is used by approximately 100 gallons by the average person every day, but we all know there will be a few water hogs. You should calculate the size of your tank based on how much money you spend on drinking water in one year (in dollars) and the cost per gallon from a commercial softener.

When your business spends $15,000 on drinking water, and you pay 50 cents for each gallon, a tank holding 30,000 gallons can be purchased.

You can determine the tank size for a large office building based on how much water you use in a year (in dollars) and how much it costs per gallon to soften it. When your business spends $15,000 on drinking water, and you pay 50 cents for each gallon, a tank holding 30,000 gallons can be purchased.

what size water softener for a family of 6

A 40-gallon capacity, a 50-stage water softener is best for a family of six. This site will have enough capacity to handle the needs of a large household without being too large.

However, if you have small children or pets that consume a lot of water and produce more waste than the average family then you should consider getting a larger softener. If your household drinks about 20 gallons of water per day then a 60-gallon or 80-gallon capacity softener will be needed.  

If you have a family of six and drink about 30 gallons per day then a 90-gallon capacity softener will be needed. If your household drinks more than 40 gallons of water per day then you will need to get a larger softener.

How Large of a Water Softener Is Suitable for family 3?

The answer to this question is complicated, so I have written a detailed answer below.

To know what size water softener is best for your family of 3, you'll need to know:

  • How many gallons per day is used by your family of 3.
  • What type of water softener is most appropriate for your situation.
  • Is the minimum flow rate for your water softener.
  • What is the largest capacity of your water softener?
  • What is the size of your tank?

what size water softener for a family of 2

A good size for a family of 2 people would be the 8-gallon model. If there are more people in the family then you should get a larger softener.

Good to know about under sink water softeners: The average person only needs 1/2 pound of salt per month to soften their water. The 8-gallon model will hold enough salt for up to 2 months before it needs refilling.

You can also get by with a smaller system but the salt will need to be refilled on a monthly basis. If you live in an area where the water is particularly hard, then getting a larger system might not be enough. You should contact your local water utility for more information on the hardness of your water.

Watch how to size your water softener

Frequently Asked Questions (FAQs) about How to Size a Water Softener

The following frequently asked questions and answers will help you know more about how to size a water softener.

1. Does the size of a water softener affect efficiency?

Yes. Water hardness determines the size of a water softener. If you choose an extremely large water softener and an extremely small softer, it will affect regeneration, which is essential for water efficiency.

2. I use well water at my house. How can I determine the level of water hardness?

Most wells have so much iron content, which affects the quality of water. To know if your well has one, you will get brown stains on your fixtures.

3. What is the proper size of a home water softener?

The best way to know how much water you need is to take the square footage of the home and multiply it by four. This will give you an approximate number of gallons per day that you'll need, and you'll know how many gallons of water the softener will be able to process.

4. What does 64 000 grain softener mean?

64 000 grain softener means 64,000 grains of water can be removed from a single liter of water. This is the same as 64 kilograms of salt.

If you have a water softener that treats 50 liters per hour, it will take (50 l/hr)(64 kg)=3,200 hours or 73 days to get rid of all that salt.

If you have a water softener that treats 10 liters per hour, it will take (10 l/hr)(64 kg)=640 hours or 12.7 days to get rid of all that salt. If you have a water softener that treats 2 liters per hour, it will take (2 l/hr)(64 kg)=128 hours or 3.4 days to get rid of all that salt.

5. If I have a too-small water softener, what happens?

If the water softener is too small, you will have a buildup of minerals in the tank. These minerals can cause problems with the machine and can be difficult to remove without professional help.

6. How does an oversized water softener affect my water?

If your softener is too large, it will run all the time and use a lot of water. You can avoid these two problems by knowing how to size a softening system for your house correctly.

7. Can you tell me what size water softener I need for my family of 4?

The water softener you need depends on the size of your family. For example, if you have a family of four people, then you will need a water softener that has a capacity of 60,000 gallons.

8. What is the right size water softener?

The right size water softener depends on the number of people in your house and how hard their water is. There are two types: whole-house and point-of-use. Whole house softeners are the most expensive, and they filter your whole house. They are the cheapest, and they don't take up a lot of room. They also need a lot of space. Point-of-use softeners only filter the water coming out of your faucets.

9. Is bigger better for a water softener?

Yes, bigger is better for a water softener. The bigger the capacity of your water softener, the more effective it will be in filtering out any harmful chemicals present in your home's water.

10. What does 64 000 grain water softener mean?

The 64 000 grain water softener is a type of water softener that uses granular media to remove hardness from the water. It also removes other minerals such as calcium and magnesium, which can cause scale and rust. The granular media in this softener is a combination of alumina, silica, and iron oxide.

11. Is it necessary to replace my water softener if it is too high?

It is a common misconception that a water softener can make your water harder. This is not true, and in fact, the reverse happens. Too much salt in your water will cause it to be too hard, and you may have trouble using it. The salt will also cause your water to become cloudy, and in some cases, the chlorine in the water will create a bad taste and smell.

12. What is a Good Number for Water Hardness?

There can be no "perfect" number for water hardness. The best way to determine your water hardness is to have a professional test it.

Final Words & Recommendations

A water softener is an effective solution to curbing water hardness and ensuring your water is safe for drinking. However, to adequately size your water softener, a couple of factors and steps are considered that have been explained in this article on how to size a water softener.

Properly sizing a water softener is ideal and will go a long way in determining the amount of required hardness in water it has to remove without exhausting its capacity, breaking the valve, and reducing its efficiency.

Click Here to Leave a Comment Below 0 comments

Leave a Reply: