What Size Water Softener Do I Need? [Calculation Matters]

Introduction To Water Softener Sizing

Water softeners come in a variety of sizes that indicate how many grains of hardness they can remove before requiring regeneration. A water softener that is too small may run out of softening capacity sooner than expected, lower water pressure and flow rate, take more time and money to maintain, and wear out prematurely.

A system that is too huge, on the other hand, is not only expensive to acquire, but it will also harm the resin bed due to rare regeneration cycles.

Water softener sizing tools may be found all over the internet to assist users in selecting the appropriate softening size. Unfortunately, the great majority of these calculators do not account for water softener efficiency.

As a result, many people choose a water softener that appears to be the right size but consumes a lot of salt (typically more than 2000 pounds per year) instead of a properly sized, efficient one that uses 300 pounds per year. What causes this to happen?

Simply said, many dealers, both online and in-store, are unfamiliar with the idea of water softener salt efficiency and do not account for it in their size calculations which also takes the number of people, gallons per person and grain unit into account.

In this article, we will aid you in understanding your daily softening requirement, and how many grain water softeners do you need, so that you can invest in a proper water softener.

Why should I care to size a water softener and its efficiency

Starting off in terms of efficiency, your water softener’s efficiency determines how much salt you’ll need to buy, how much salt you’ll have to transport, and how much salt will be released into the environment.

When you size a water softener and consider its salt efficiency, you’ll get a water softener that not only never runs out of soft water, but also uses the least amount of salt. This leads to considerable cost savings and simplicity of ownership during the life of the water softener.

Moving on to size a water softener, many customers are inclined to disregard the size of water softener tank. They simply look for the cheapest unit when they ask themselves which water softener do I need, which is generally lower in size. However, this is not a good option.

Undersized water softener

A water softener that is too small for your family will not create enough soft water. As a result, after a certain amount of use (or if you open too many taps at once), the unit will be bypassed, allowing hard water to flow through your pipes. This, of course, undermines all of the great water softener advantages you were hoping for.

Furthermore, a water softener that is too tiny will need to be regenerated more frequently. When your water softener regenerates, it flushes out the minerals that have built up in the resin beads.

This regeneration mechanism is dependent on demand in many modern systems; the more minerals that pile up in the beads, the more often it will regenerate. The life of these resin beads, as well as your water softener as a whole, is shortened when they are regenerated too frequently.

You want to prevent this since, as you know, these softener systems aren’t inexpensive.

Oversized water softener

Except for the fact that you will pay more money up front, large water softeners aren’t necessarily as terrible as an undersized one. The unit will utilise salt more effectively and regeneration will be less frequent. When regeneration occurs, it will, of course, need more water and salt, but the fact that the cycles occur less frequently may offset this.

Even if you do get a large water softener, you must understand what the capacity statistics supplied by the manufacturer represent. Otherwise, you won’t be able to accurately predict how much salt you’ll need.

Factors To Consider When Finding The Right Water Softener Size

Determining water hardness level – grains per gallon

The amount of calcium and magnesium dissolved in your water is measured here. This information will be provided in mg/L (milligrammes per litre) or GPG (grammes per gramme) depending on where a water test is done (grains per gallon).

Water hardness is measured in grains per gallon, which is the industry standard. When you divide mg/L by 17.1, you get GPG, as 1 ppm = 1 mg/L and 1 gpg ≈ 17.12 ppm = 17.12 mg/L. Water hardness is measured in “grains,” which are equal to 1/7000th of a pound.

When considering the purchase of a softener, it’s critical to determine your water hardness. If you guess at this amount, you’ll end up with an undersized system. Your softener will also ask for the water hardness value when it comes time to programme it. You’ll have to test for water hardness if you’re on your own.

If you have city water, your local water provider can generally tell you how hard it is. Their yearly reports are frequently available online. The hardness value must be adjusted when iron is present in the water. 3 GPG of water hardness must be added to the overall hardness result for every 1.0 ppm or mg/L of iron.

You can find out what water hardness level you are dealing with simply via a couple different options. First option is that you may test the calcium levels in your water and measure them yourself. For less than $20 USD, test kits are commonly accessible online.

You may also get your water analysed by a third-party lab, but definitely not by someone who is trying to sell you anything in your living room.

Estimating your daily water consumption

Your household’s water consumption is the second element utilised to determine the daily softening need. Looking at a water bill that indicates total use over a particular period of time – generally a month – is the most accurate approach to determine this.

You may use this data to estimate how much water your home consumes on a daily basis. If you don’t know, increase the number of people in your home by 75 gallons each day. This will give you an estimate of how much water you consume on a daily basis.

Calculating your daily softening requirement

Firstly, multiply your daily water use by the hardness of your water (corrected for iron). This is your Softening Requirement for the Day. Here’s an illustration:

The hardness of the water is 10 grains per gallon.

Water Consumption on a Daily Basis: 4 people x 75 gallons per day = 300 gallons per day

10 grains per gallon multiply the number 300 gallons per day equals 3000 grains per day.

Calculating your required total grain capacity

When it comes to calculating total grain capacity, first of all it is vitall to know that a water softener can only remove a certain number of hardness granules before it has to renew. This is due to the way the softening process operates. All resin beads in the softening tank will eventually be saturated, meaning they won’t be able to bind any more calcium or magnesium ions.

The collected minerals are washed and drained away during regeneration, and the resin bed is refilled with sodium or potassium.

Experts recommend that a softener be regenerated every six to seven days. This achieves an excellent mix of high softening efficiency, minimal wastewater output, and head valve wear protection. It will also protect the resin from iron and selenium.

We acquire a total softening capacity of 25,200 grains by multiplying our daily softening demand of 3,600 grains by 7 days:

3,600 grains of hardness each day multiplied by 7 days is 25,200 grains (per week)

Salt efficiency

This would theoretically allow us to renew a 25,200-grain water softener once a week while never running out of soft water. What is the point of speaking theoretically? Because we haven’t considered salt efficiency, also known as brine efficiency, up until this point.

Simply said, full regeneration of a softener’s resin bed necessitates a disproportionately large amount of salt, whereas partial regeneration is far more effective. Consider the following example:

A 33,000-grain unit requires 14.1 lbs of salt to fully renew. To renew 13,000 grains, the same machine uses just 2.6 lbs of salt. You could renew 27,600 grains using 8.3 lbs of salt.

The softening capacity increases as the salt dose increases, while the efficiency per pound of salt decreases.

Bottom line: If you need a water softener to remove 25,200 hardness grains each week, as estimated in our example, choosing a system with a greater grain capacity – say, 40,000 grains – will save you a lot of money on salt in the long run.

Furthermore, maintenance would be considerably easier, and less salt will be released into the environment, posing a hazard to aquatic life. If you have one, it will also improve your sewage system.

To be clear, the reason you need a greater grain capacity than predicted is because if you don’t let your softener regenerate to 100%, it will quickly exhaust. A larger system can compensate for this impact.

Flow rate

It’s all well and good to have daily and weekly softening capacity, but if your softener can’t supply enough soft water at high usage periods, hard water will seep through and/or you’ll notice a reduction in pressure and flow.

This is especially true in the mornings, when everyone is getting ready for work or school. There may be numerous showers and faucets running, toilets flushing, and the dishwasher started before you left the house. As a result, pay close attention to service flow rates in gallons per minute (gpm).

Larger houses, on average, need greater flow rates. Single-family homes may be able to get by with 6 or 7 gpm. A minimum flow rate of 12 gallons per minute is recommended for households with two or more bathrooms. Families with a lot of water should search for systems that can pump out at least 15 gallons per minute.

The typical water use of modern outlets like faucets would be 1.0 gpm, 3.0 gpf for toilet, 2 to 2.5 gpm for shower, 6 to 16.0 gpl for dishwasher and 25.0 gpl for washing machine.

Selecting The Right Water Softener Size To Match Your Household Conditions

You’ve calculated how much softening is necessary every day based on your local circumstances and water use. Water softeners are typically sized such that they renew once a week or less. Why is it only once a week? A once-week regeneration achieves a nice compromise between keeping the resin bed fresh and preventing the valve from suffering excessive wear and tear.

Moving components are included in a water softener valve, however they only move while the water softener is renewing. Regenerating once a week also saves water; when a water softener regenerates, it requires roughly 50 gallons of water.

If we double the Daily Softening Requirement of 3000 grains each day by seven days, we’ll need a water softener that can soften 21,000 grains of total hardness once a week to renew. So, what size water softener has a total softening capacity of 21,000 grains? This is where a lot of false information on the internet and elsewhere may obscure the true answer.

Water softeners with grain capacities of 24,000, 32,000, 48,000, and 64,000 grain capacity may be found in plenty online and in numerous places. Using our example above, where we’re seeking 21,000 grains of overall softening capability, it appears that the 24,000 grain system would be suitable.

Unfortunately, the 24,000 grain system’s resellers neglect to mention that the system requires 27 pounds of salt to fully renew to the 24,000 grain level. “0.75 cubic feet” is a more realistic description of the “24,000” system.

This is the total amount of resin in this system.While it is true that this amount of resin may yield 24,000 grains of capacity, it does so at the expense of a large amount of salt.

Because it includes one cubic feet of softening resin, what most dealers term a “32,000” grain system is more correctly defined as a “1 cubic feet” system. The user would have to consume 36 pounds of salt every regeneration to achieve 32,000 grain capacity from this device!

However, it’s worth noting that using 6 pounds of salt to renew a one-cubic-foot system will result in 20,000 grains of softening capacity. Although a one cubic foot unit will cost somewhat more than a 0.75 cubic foot one, the cost difference will be soon offset by the savings in salt. There will be less salt to buy, transport, and dump into the environment.

Conclusion: Size Your Water Softener Properly!

It’s difficult to know how to size a water softener. You are the only one who can determine how many grains your system needs to function properly.

When it comes to determining “what size water softener do I need?” or “what grain water softener do I need?”,evaluating your home needs can assist you in making the best decision to pick a good size water softener for your household.

At least 48,000 grain units of softener are required for most large 4-person families who consume a lot of water. Depending on how you live and the number of people at home and daily softening requirement, your house may require a larger or less grain water softener capacity than this.

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