Water softener installation for pros: advanced tips & reminders
In both residential and commercial applications, proper water softening is critical to protecting plumbing systems and maintaining performance. The tough minerals sourced into water systems can do great damage if left unchecked, so proper water softener installation is paramount. While some homeowners attempt DIY installs, professional plumbers are more likely to know things like how to install a water softener in a pre-plumbed house or how to install a bypass valve for water softener regeneration, among many other aspects, making it a safer bet to contact a pro.
As a plumber, when you’re called for a water softener installation contract, keep these best practices in mind to ensure a reliable, code-compliant installation.
Finding the Right Size Water Softener
When it comes to determining proper water softener sizing, it’s important to gather some crucial details.
Hardness Level
Start with testing the hardness level of the water to determine the grains per gallon (GPG). Water hardness typically ranges from 5–10 GPG in moderately hard areas to 75–100 GPG in extreme cases, depending on the local water supply.
Due to unique geological, environmental, and infrastructural factors—water hardness levels vary across regions. Aside from Florida, coastal regions have lower water hardness levels because much of the water is sourced from lakes and rivers which typically aren’t in contact with underground rock formations long enough for hard minerals to mix in. Water hardness levels rise to relative extremes closer to the midwestern regions—and Florida—due to the mineral-rich grounds the water must be sourced from.
Daily Water Use
The average residential water use is approximately 75–80 gallons per person per day. You can approximate daily water usage by multiplying this number by the amount of people in the household.
Ex: 80 gallons per day x 4 people = 320 gallons per day
Daily Hardness Load
Now that you have the household’s approximate daily water usage, you can estimate the total daily grain load by multiplying the daily water usage by the hardness level.
Ex: 320 gallons per day x 10 GPG = 3,200 grains a day
Iron
The presence of iron significantly alters your calculations because it significantly increases the hardness load on the system. The best way to account for iron is to add anywhere from 3-5 GPG per every 1 unit of iron found after testing the water hardness level.
Ex: 6 units of iron found in water.
3 GPG x 6 iron = 18 GPG
10 GPG + 18 GPG = 28 GPG
320 gallons per day x 28 GPG = 8,960 grains a day
Water softener units are sized by grain capacity. Now that you have your calculated estimate of the daily hardness load, you can multiply 7, for the number of days in a week, and use that final number to determine the size unit you would need.
Ex: [No iron] 3,200 grains a day x 7 days a week = 22,400 grain capacity water softener
[With iron] 8,960 grains a day x 7 days a week = 62,720 grain capacity water softener
If you’re in between sizes, it is better to install a unit with excess capacity than one that is undersized.
Water Softener Sizing Chart
| Grains Per Gallon | 1-2 People | 3-4 People | 5-6 People | 7-8 People |
|---|---|---|---|---|
| 5-10 GPG | 32,000 Grain | 32,000 Grain | 40,000 Grain | 48,000 Grain |
| 11-20 GPG | 32,000 Grain | 40,000 Grain | 48,000 Grain | 64,000 Grain |
| 21-30 GPG | 32,000 Grain | 48,000 Grain | 64,000 Grain | 80,000 Grain |
| 31-40 GPG | 48,000 Grain | 64,000 Grain | 64,000 Grain | 96,000 Grain |
| 41-50 GPG | 64,000 Grain | 80,000 Grain | 96,000 Grain | 110,000 Grain |
| 51-75 GPG | 64,000 Grain | 80,000 Grain | 96,000 Grain | 110,000 Grain |
| 76-100 GPG | 80,000 Grain | 96,000 Grain | 96,000 Grain | 110,000 Grain |
Programming the Water Softener
Efficient water softening can be accomplished with smart programming—ensuring that water regeneration occurs in a manner that aligns with the household’s actual water usage. Water softeners have settings that allow for specificity in a household’s water regeneration.
Household Specifics
The most fundamental setting is the GPG of the water supply, then the household size. So be sure to test the water hardness level while adjusting for the number of residents for the most accuracy when programming the water softener.
Regeneration Cadence
You can program the water softener to regenerate on a set schedule or on an as-needed basis. If the customer prefers scheduled regeneration, it’s best to set it for the hours just past midnight, so that they have soft water available at the times they would commonly need it.
Programming the water softener to regenerate based on need is typically more efficient since it considers actual water consumption, as opposed to just regenerating on a fixed schedule regardless of actual demand.
Water Softener Installation Necessities
Test Kit
The first step of proper water softener installation is testing the water for hardness, so having a water test kit is essential to accurate sizing and programming.
Air Gap
Not only is an air gap essential to water softener installation—it is required by water softener drain line code, as it prevents cross-contamination from the drainage system. Install an air gap at least twice the diameter of the drain line to meet typical code requirements.
Bypass Valve
A bypass valve allows the system to be serviced without shutting off the building’s water supply. This is especially valuable in commercial settings or in homes where large volumes of untreated water may be needed for tasks like filling pools or irrigation.
Key Installation Reminders
- When deciding on a size, it’s safer to install a unit with excess grain capacity than one that is undersized.
- Installing a water softener air gap is not a suggestion—it is a requirement. Skipping this step can create serious cross-contamination risks.
- When repairing a water softener, inform your customer that the bypass valve is allowing hard water back into the supply so they will be receiving untreated water until repairs are complete.
Shop for your water softener installation needs with the supply of tools available at Ferguson. Ferguson stocks the tools, valves, and treatment components you need to complete water softener installations with confidence.