Water Check · hardness, filters, softeners
What's in your water, and what to install for it
Start from a number — your utility's water report, a test kit or a lab result — and what you notice at the tap. Water Check lists the treatment steps in order, sizes a softener, and shows price ranges, with the source behind every figure.
- 1 Pick your water source
- 2 Slide to your hardness number
- 3 Read the verdict — it changes as you slide
An AI tool drew the illustrations on this page as simple diagrams. They are not photographs of real homes, water systems, products or people.
Reference
Hardness classes
| Class | gpg | mg/L (ppm) |
|---|---|---|
| Soft | 0–1 | 0–17 |
| Slightly hard | 1–3.5 | 17–60 |
| Moderately hard | 3.5–7 | 60–120 |
| Hard | 7–10.5 | 120–180 |
| Very hard | > 10.5 | > 180 |
Source: Penn State Extension, Water Softening, Table 1 (updated Sep 8, 2025).
Lab notes
Read next
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- Hard Water vs Soft WaterHard water vs soft water side by side: minerals, scale, soap, appliances, sodium in softened water and what it costs to switch, with each point sourced.
- How to Test Water HardnessHow to test water hardness: check your water report, use test strips or a drop-count kit, or send a sample to a lab, then read the result in gpg or mg/L.
- Iron Filter for Well Water: Match the Treatment to Your Iron LevelWhy well water stains orange, what your iron and manganese numbers mean, which treatment fits which level, and what iron filters cost.
- Salt-Free Water Softeners: Do They Work?Most salt-free conditioners don't remove hardness; at best they reduce scale. What independent sources say, which standards exist and how to check a claim.
- Sediment vs Carbon Whole House Filters: What Each RemovesA sediment filter strains out sand and silt by size; a carbon filter adsorbs chlorine, tastes and odors. Micron ratings, costs, and when you need both.
- Sulfur (Rotten Egg) Smell in Well Water: Find the Source FirstHydrogen sulfide gas can give well water a rotten-egg smell. How to tell a water heater problem from a well problem, what to test, and treatment by level.
- Water Hardness Scale: gpg, ppm and mg/L ExplainedThe water hardness scale in grains per gallon and mg/L: how Penn State Extension and USGS classify soft to very hard water, and how to convert your number.
- Water Hardness Test Kits: Strips, Drops or a Lab?Water hardness test strips, drop-count kits, lab tests and TDS meters compared from maker specs and extension advice: what each measures and what it costs.