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Water Softener Settings Explained
Water softener settings come down to four values: hardness in grains per gallon, an allowance for iron, the regeneration time, and capacity with its reserve. Set hardness from a real water test and the rest follows from your valve's manual.
Disclosure: watersoftenerguide.net is owned by the team behind SoftPro Water Systems and Quality Water Treatment, which sell some of the parts and systems we link to. Our steps follow the makers' manuals and published instructions, checked October 2026. Always check your own model's manual first. Ownership disclosure
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Quick answer
- Enter hardness in grains per gallon (gpg); divide mg/L by 17.1.
- Raise the hardness setting for dissolved iron in well water.
- Regeneration usually runs overnight, when nobody is using water.
- Capacity minus reserve decides how many gallons pass between regenerations.
- A weekly regeneration on a lean salt dose is the usual target.
The settings that matter
Every salt-based softener needs to know two things: how hard your water is and how much hardness its resin can hold. From those, the control works out how much water it can treat before it must regenerate. Everything else on the menu either fine-tunes that sum or sets when the regeneration happens.
The names vary by valve. On a Fleck 5600SXT, the manual lists them in this order in Master Programming: display format, valve type, control type, number of tanks, unit capacity (C), hardness (H), reserve type, safety factor or fixed reserve, day override (DO), regeneration time (RT), the four cycle step times, and the flow meter type. The everyday values sit in a shorter user menu. The Fleck 5600SXT manual guide walks through each screen, and the control valve guide explains how the valve uses them.
| Setting | What it means | Where the number comes from |
|---|---|---|
| Hardness | Grains per gallon in the incoming water | A water test or your city's water report |
| Iron allowance | Extra grains added for dissolved iron | A test for iron in the raw water |
| Unit capacity | Grains the resin removes between regenerations | Softener size and salt setting |
| Reserve | Capacity kept back for water used before regeneration | Manual or installer |
| Regeneration time | Hour the cycle starts | Usually overnight |
| Day override | Most days allowed between regenerations | Manual or installer |
Setting hardness
Hardness drives every other setting, so get it from a real test. Set too low, the softener runs out early and hard water slips through. Set too high, it regenerates more often than needed and wastes salt and water.
- Test the raw water. Take the sample from a tap ahead of the softener, or put the softener in bypass first. Use cold water. City customers can also read hardness from the annual water quality report (Consumer Confidence Report). The hardness testing guide compares test strips, drop-count kits and lab samples.
- Convert to grains per gallon. A reading in mg/L (the same as ppm) becomes gpg when divided by 17.1, and SoftPro's install guide rounds the answer up. For example, 205 mg/L ÷ 17.1 = 12 gpg.
- Enter it. Pentair's 5600SXT manual accepts feedwater hardness from 1 to 199 gpg.
- Check the result. After the next regeneration, test a softened cold tap. A big gap between raw and softened readings means the setting is doing its job.
A drop-count kit gives a more precise reading than strips. For a raw-water reading before you program the valve, the Pro Products 2403 field test kit (sold by Quality Water Treatment, our store) is from $150.00 (October 2026) at Quality Water Treatment. Its listing describes three 1 oz hardness reagents, a sample bottle and measuring tube, all packed in a sturdy case.
Adding iron to the hardness setting
Dissolved (clear-water) iron uses up resin capacity the same way calcium and magnesium do. If you don't account for it, the softener runs out before it regenerates. Install guides handle this with a higher hardness setting that covers the iron too.
Valve makers give their own figures, so follow your softener's manual. SoftPro's Elite install guide, for example, says to add 3 gpg to the hardness setting where iron is 2 to 3 ppm and no iron filter is fitted. Use the figure in your own softener's guide, and check treated water for iron staining after a few weeks.
Iron has limits on a softener. A softener can handle small amounts of dissolved iron with suitable resin, but red or orange (oxidized) iron, iron bacteria, higher iron levels and rotten-egg sulfur need a dedicated filter ahead of the softener. Iron also fouls resin over time, so plan on a resin cleaner; the resin cleaner guide covers doses.
Regeneration time and capacity
Regeneration time (RT). In Pentair's manual, RT is the clock time at which any delayed, queued or day-override cycle begins. Pick an hour when no one is using water, because the house gets unsoftened water during the cycle. Quality Water Treatment's Fleck guide sets 2:00 am "or your suitable time". The Fleck manuals don't state a factory default, so check yours.
Capacity. Per the Fleck manual, the control takes the unit's grain capacity, divides it by the hardness you entered and subtracts the reserve. The answer is how many gallons it softens between regenerations. Rated capacity depends on salt. Pentair's smallest 5600SXT system, with one cubic foot of resin, is rated for 31,100 grains on a 9 lb salt dose, and its larger tanks scale up in proportion. Lower salt settings deliver less capacity per regeneration but more grains per pound of salt.
Reserve. The reserve keeps some capacity back so you don't run out of soft water before the overnight regeneration. Pentair's valve takes it either as a percentage safety factor, anywhere from zero up to half the capacity, or as a set number of gallons capped at 50% of the calculated figure. Quality Water Treatment's Fleck setup uses 15%.
Day override (DO). The DO value caps the days between cycles, so a lightly used softener still regenerates now and then. Pentair permits Off or up to 99; Quality Water Treatment enters 14 on its systems.
A worked example helps. Penn State Extension describes a 20,000-grain unit in a four-person home with 10 gpg water: 4 people × 75 gallons a day × 10 gpg = 3,000 grains a day, so it regenerates every 6 to 7 days. The target for most homes is roughly a weekly cycle on a lean salt dose. The store guides range widely, from a cycle every 2 days to one every 7, depending on hardness and household use, so let your manual decide. The guide to how often a water softener should regenerate goes deeper, and the regeneration guide explains the cycle itself.
On a SoftPro Elite valve, the install guide also sets a refill rate of 0.2 for city water and 0.7 for well water. Settings lost after an outage or error can be restored with the steps in how to reset a water softener.
Related guides
Common questions
Should the hardness setting be higher than the test result?
Enter your measured hardness, rounded up to the next whole grain, plus any iron allowance your manual calls for. Padding the number further makes the softener regenerate more often than it needs to and uses more salt.
Which hardness setting should a city home use without a test kit?
Read the hardness figure from your utility's annual water quality report and convert mg/L to gpg by dividing by 17.1. A home test is still worth doing, since hardness can vary with the source.
Does the salt setting change the softener's capacity?
Yes. Every capacity rating assumes a particular salt dose, which is why Pentair quotes each model with its pounds of salt. A smaller dose recharges less of the resin but removes more grains per pound.
What reserve should a family of four set?
Follow your manual or installer. Quality Water Treatment uses 15% on its Fleck systems, well inside the range Pentair's valve accepts. A bigger reserve suits homes with heavy evening water use.
Parts for this job
Pro Products Water Hardness Field Test Kit
Check current options and prices at Quality Water Treatment.
View at Quality Water Treatmentwatersoftenerguide.net is owned by the team behind SoftPro Water Systems and Quality Water Treatment, which sell some of the parts and systems we link to. Ownership disclosure
More help: see our water softener how-to guides.