How Big of a Water Softener do I need for My House

Water softeners come in a variety of sizes that indicate how many hardness granules they can remove before needing to be regenerated.

However, selecting the correct size is critical since a softener that is too small will exhaust its softening capacity ahead of schedule, reduce water pressure and flow rate, need more time and money to operate, and will wear out prematurely.

These water-softeners have the potential to improve people’s way of life. Better softeners do eliminates irritations to the body and psyche you may experience because of hard water.

These include: dry skin and hair, low-lathering soaps, stains, scum, bad smell, funny taste and the long-run expenses of replacing costly hot-water-using appliances when they break.

Most industrial experts and individuals agree that hard water is not much of an actual health concern. While the outcome of hard water varies, they’re consistent in the quiet confusion they create each day and in the long term.

Those who are responsible for their own water supply could result to a deeper knowledge of water softeners and as well from conducting a water-softeners comparison.

Factors You Need to know before getting a size of water softener you need

  • Flow Rates

Flow rates are always measured in gallons per minute (GPM).
It’s a crucial thing not to undersize your water softener when it comes to flow rates.

If your water softener is too small and you try and use too many fixtures, you will experience a large drop in water pressure followed by hard water and iron bleed.

The well-engineered system incorporates the internal diameter of the bypass valve, control valve, mineral tank, distribution system, as the volume and type of ion exchange softening resin.

The combination of these components will determine the flow rate of a well water softener that can support it.

Tip to calculate: Add the maximum number of fixtures you could use at once (2 sinks + 1 toilet + 1 bathtub).

  • Water Volume

The normal Average domestic water use is 75 gallons per day per person (75gpd/person). This means that an average family of 4 would use 300 gallons per day.

Heavy water use can easily add up to 100gpd/person or more.
Tip to calculate: Multiply the maximum number of people y your estimated use/person (4×100 = 400gpd)

  • Water Quality

All Water softeners are used to remove dissolved calcium, magnesium, iron, and manganese.

This Calcium and magnesium are measured in grains per gallon (gpg) whereas iron and magnesium are measured in parts per million (ppm).

When you size a water softener, you have to remember to convert the measurement of all minerals into grains per gallon (gpg).

Tip to calculate: Multiply parts per million (ppm) of iron and manganese x4 to convert them into grains per gallon.

How to Calculate Total water hardness

20gpg hardness
4gpg iron (1ppm x 4)
1gpg manganese (0.25ppm x 4) = 25gpg total hardness
Tip to calculate: It is far more efficient and effective to use an iron filter to remove iron and manganese instead of a water softener.

  • System Capacity

The Water softeners are full of little pieces of plastic beads called ion exchange resin. These resin beads remove hard water minerals by pulling them out of the water much like a magnet.

A water softener’s capacity is very based on the amount of resin inside the unit. 1 cubic foot of resin can be removed 32,310 grains of hard water minerals (calcium, magnesium, iron, and manganese).

Tips to calculate: Common residential sizes include 0.75, 1.0, 1.5, and 2.0 cubic foot systems

Once the system has reached capacity, the resin beads will be covered with minerals, and be incapable of softening the water.

At this point, the water system will have to clean itself out with salt (known as regeneration) to resume softening.

Tip 2: You have to make sure you don’t run out of soft water between regenerations, add 30% extra capacity for a reserve or safety factor.

  • Regeneration Frequency

Mechanical components in a water softener only have to work during the regeneration process.

During service, water simply flows through the system.

Metered water softeners measures the amount of water you use, and it will try and regenerate often enough to keep up with usage.

An undersized water softener will have to regenerate regularly, and its mechanical components will work overtime.

The excess load reduces the lifespan of all mechanical components.

Tips: The ideal water softener size has enough capacity to last 4 days between regenerations.

How to Properly Size a Water Softener

There is a right way to sizing a water softener; by matching your specific water quality and water use to a sufficiently sized softener that minimizes salt use and maximize soft water capacity.

Water Hardness

This is the measure of how much calcium and magnesium in quantity is dissolved in your water.

It Depends on where a water test is performed this information will be reported in mg/L (milligrams per Littre) or GPG (grains per gallon).

The Grains per gallon referrers to industry-standard mode to talk about water hardness. Diving mg/L by 17.1 converts it to GPG. A “grain” of water hardness and its equivalent to 1/7000th of a pound.

Looking at the numbers results in improperly sized softeners. However, when it comes to programming time your water softener requires for the hardness value.

When you’re on your well you will have to test for hardness. If you’re on city waters you can usually get the hardness level from your local water utility.

When iron is present in water, the hardness value must be corrected.

For every 1.0 ppm or mg/L of iron, 3 GPG of hardness is required to add to the total hardness value.

Water Consumption

The other factor to be used to calculate your daily softening water requirement is your household consumption.

The accurate way to calculate is to read at a water bill which shows total consumption over a certain period of time, normally a month.

You can as well use this billing information to figure out how much water your household consumes per day, on average.

If you don’t have access to this information, just multiply the number of people living in your household by 75 gallons per day. This will give a fairly accurate guess estimate of daily water use.

Steps are involved in sizing a water softener:

  • Determining Your Water Hardness Level

Water is classified as “soft”, “moderately hard”, “hard”, etc. depending on its calcium carbonate concentration.

The water Levels are as well measured in ppm (parts per million), mg/L or gpg (grains per gallon), this is the industry standard used to measure.

For you to convert from ppm or mg/L to gpg, you have to divide by 17.12.

1 ppm = 1 mg/L and 1 gpg ≈ 17.12 ppm = 17.12 mg/L

Hardness Chart

Soft0 – 600 – 600 – 3.5
Moderately hard61 – 12061 – 1203.56 – 7.01
Hard121 – 180121 – 1807.06 – 10.51
Very hard>180>180>10.51

You are required to pay more attention to high iron levels, more so when you receive water from a well. For each and every 1 ppm of iron, you have to add 4 gpg to the total hardness value.

Some experts as well recommend to adding 4 gpg per 1 ppm of manganese.

  • Calculation: Hardness Measured at 140 ppm, Iron at 1 ppm

140 ppm / 17.12 = 8.18 gpg
8.18 gpg + 4 gpg (equals iron at 1 ppm) = 12.18 gpg (total hardness)
2. Estimating Your Daily Water Consumption

This step is to estimate your family’s daily water consumption. If you want to take out all the guesswork you should consult your current water bill.

It’ll list your consumption within a certain time period think of a month, quarter or year. Use this number to calculate the daily average.

Calculation 1: 36,000 Gallons Usage in Q4 2018
36,000 gallons / 90 days = 400 gallons (per day)

Calculation 2: 4-Person Family, 90 Daily Gallons per Person
4 persons x 90 gallons/person = 360 gallons (per day)

  • Calculating Your Daily Softening Requirement

Lastly, you have to multiply the hardness level by the daily water usage. The result you get is the daily softening requirement that means, it’s the hardness grains a softener has to remove from your water on a daily basis.

Calculation: Water at 10 gpg, 360 Gallons per Day
10 hardness grains/gallon x 360 gallons/day = 3,600 hardness grains (per day)

If your water measures at 10 gpg and you use 360 gallons a day then your potential new softener would need to remove 3,600 hardness grains each day.

  • Calculating Your Required Total Grain Capacity

A water softener system is capable to remove so many hardness grains before it has to regenerate. This goes with how the softening process works.

At a point, all resin beads the softening tank saturates, thus they can’t bind any more calcium or magnesium ions.

Regeneration involves washing out and draining away all the accumulated minerals and recharging the resin bed with sodium or potassium.

Many experts recommend regenerating a water softener about every six to seven days.

This provides for a better balance between high softening efficiency, low wastewater production and protecting the head valve against wear. It’ll also conserve the resin protecting it against iron and sediment.

By multiplying your daily softening requirement of 3,600 grains by 7 days the result you get is the softening capacity of 25,200 grains:
3,600 hardness grains/day x 7 days = 25,200 grains (each week)

  • Considering Salt Efficiency

Theoretically speaking, this would give us room to regenerate a water softener with a 25,200-grain rating once a week and never run out of soft water.

Why theoretically speak? Is Because up to this point we haven’t note any account of salt efficiency, brine efficiency.

Simply place, a regenerating water softener’s resin bed to 100 percent needs a disproportionately high amount of salt, thus partial regeneration is much more efficient.

For instance, In order to perfectly regenerate a 33,000-grain unit, 14.1 lbs. of salt are needed.

The same model also requires no more than 2.6 lbs of salt to regenerate 13,000 grains. And with these 8.3 lbs of salt, you could regenerate 27,600 grains.

However, only recharging approximately. One-fifth of the salt is required for 40% of the softening bed, while three-fifths of the salt is required for around 84 percent regeneration. Obviously, this is a cleverer way to operate a water softener.

Format Calculator for calculating Daily Softening Requirement

You have to multiply your daily water use by your water hardness (corrected for iron). This number is your Daily water Softening Requirement.

See an example here:

  • Hardness = 10 grains per gallon.
  • Your home Daily Water Use = 4 Persons X 75 Gallon/ day = 300 gallons/day.
  • The Daily Softening water Requirement = 10 grains/ gallon X 300 gallons / day = 3000 grains / day.

In the above example, the water softener will be removing 3000 grains on a daily basis. A water softener is normally sized to regenerate approximately once per week.

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