# WaterGradePro: Home Water Filters and Softeners, Graded

> Water softeners, whole-house filters, reverse osmosis, refrigerator filters and well water, compared by NSF/ANSI certification and manufacturer specs.

Source: https://watergradepro.com/
Updated: 2026-11-13

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## What we cover

Eight topics, one method: what each type of system can do, which certification backs it up and how to tell whether it fits your home.

### Water Softeners

Hard water leaves scale on fixtures and appliances. A softener is sized by your water’s hardness and your household’s daily use.

NSF/ANSI 44

### Whole-House Filters

Point-of-entry systems that treat every tap. Flow rate and certified claims matter more than the number of stages.

NSF/ANSI 42 · 53

### Under-Sink & Reverse Osmosis

Point-of-use systems for drinking and cooking water, from carbon filters to reverse osmosis.

NSF/ANSI 53 · 58

### Refrigerator Filters

Match the filter to your fridge’s model number, then check what it is actually certified to reduce.

NSF/ANSI 42 · 53 · 401

### Shower Filters

Most shower filters target chlorine. The certified claim to look for is free chlorine reduction.

NSF/ANSI 177

### Well Water

The EPA doesn’t regulate private wells, so testing, treatment and upkeep are up to the owner.

Test first

### Water Testing

Utility reports, certified labs and home test kits: how to find out what’s in your water before you treat it.

Certified labs

### Contaminants

Lead, PFAS, nitrate, arsenic and more: what the EPA allows, and how a legal limit differs from a health goal.

Limits vs. goals

## Start with your water

The right system depends on what’s actually in your water, so check before you buy anything.

### On city water

Your utility publishes an annual Consumer Confidence Report that lists the contaminants it detected and the limits that apply.

[Find your water quality report](https://www.epa.gov/ccr)

### On a private well

No one tests a private well for you. The EPA explains what to test for, and certified laboratories can run the tests.

[EPA private well guidance](https://www.epa.gov/privatewells) · [Certified laboratories](https://www.epa.gov/dwlabcert)

## How we grade

Every guide follows the same four rules.

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### Certification first

We check each claim in the certifier’s own listing (NSF, WQA or IAPMO), not on the box.

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### Manufacturer data

Capacity, flow rate, filter life and replacement costs, taken from the data sheet and the manual.

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### No invented tests

We don’t run lab tests or publish made-up scores. What isn’t verified isn’t presented as fact.

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### Primary sources

Health figures come from the EPA, the CDC and the USGS, with legal limits kept apart from health goals.

[Read the full method](https://watergradepro.com/how-we-grade/)

Who runs this site

## Certification over claims.

“If a system is certified, I show you what it’s certified for. **If I couldn’t verify something, I tell you that too.** That honesty is the whole point of this site.”

**John** — Founder and Lead Writer, WaterGradePro (avatar created with AI). NSF/ANSI certifications, EPA and CDC data, and the manufacturer’s own manuals behind every recommendation. [How I work →](https://watergradepro.com/about/)

No-hype policy: no invented tests, no paid placements

Some links may earn us a commission at no extra cost to you, and it never changes a grade; our [Affiliate Disclosure](https://watergradepro.com/affiliate-disclosure/) has the details. Found an error? Tell us through our [Contact](https://watergradepro.com/contact/) page.