Methodology, Sources and Affiliate Disclosure

Where the Numbers Come From

Data	Source	How we use it
Certified claims and service flow	NSF, WQA and IAPMO R&T directories, or the certificate in the maker’s manual	Copied as listed, with the listing linked
Capacity at each salt dose, grains per pound, regeneration water	Owner’s manuals and performance data sheets	Published points only. We never fill in doses between them
Flow, limits, resin, warranty	Manuals and product pages	Quoted as maker claims
Prices	The seller’s own store on the checked date	Shown with the date; prices change often
Salt-free standards and context	IAPMO on Z601, UNL Extension G2275	Summarized with links

The current data was checked on October 22, 2026. A script checks that every value has a source before each update goes live.

We Don’t Test Systems

We haven’t tested any of these systems ourselves. Capacity, efficiency and flow come from certification records or the maker’s documents, labeled as such. Where neither exists, we say so. Certification is the fairest comparison we know, because every listed system was measured the same way, and you can check each number yourself.

Reading a Certification Record

We search all three certifiers by brand and by parent manufacturer. A badge on a product page doesn’t count without a matching listing.
We mark each system listed (performance claims certified), materials only (NSF/ANSI 61 or similar), badge unverified (a mark with no listing we could find) or none found.
When a listing covers the maker’s configuration but a retailer builds the kit, we say so. That applies to the Fleck 5600SXT.
The certifications page explains the claim codes.

The Calculator

The calculator converts mg/L to gpg by dividing by 17.1 and adds 4 gpg for each ppm of iron (Hydrotech manual). It assumes 75 gallons per person per day unless you change it, as the Hydrotech and Aquasure manuals do, and holds back one day’s use as reserve. Days between regenerations and salt per year use only the doses each maker publishes.

Community Research

We read r/WaterTreatment, r/Plumbing and r/HomeImprovement to learn what buyers ask. Reddit’s RSS feeds were blocked from our server on October 22, 2026, so we used public search results for thread titles. We never use forum posts as a source for specs.

“Not Yet Verified”

A value marked not yet verified means we haven’t found a primary source. It doesn’t mean the feature is missing. We’d rather leave a gap than fill it with a guess.

Affiliate Disclosure

Softener Specs may earn a commission when you buy through some retailer links, at no extra cost to you. As of October 22, 2026, the site has no affiliate links. Every system page has a “Where to buy” box ready for them. When links are added, they’ll read “Check Price” with a disclosure right beside them and use rel="sponsored". Commissions will never change our data, our picks or the order we list systems in, and every system gets the same box whether or not it earns us anything.

Corrections and Updates

Makers revise specs and certifiers update listings. If you spot an error, point us to a better source and we’ll update the value and its date.

October 22, 2026: launched with 13 systems, a sizing and salt calculator, a certification guide, 5 comparisons and 6 guides. All data checked October 22, 2026.

Glossary

Grain (gr): a unit of hardness. One grain per gallon equals 17.1 mg/L as calcium carbonate.
Capacity: grains of hardness a softener removes between regenerations. It depends on the salt dose.
Salt dose: pounds of salt used per regeneration.
Demand (metered) regeneration: the valve counts gallons and regenerates when capacity runs low.
Service flow: the flow at which the system still delivers soft water within its rated pressure drop.
TAC: template-assisted crystallization, the most common salt-free method. It converts hardness to crystals rather than removing it.