Hard well water: test the hardness before you buy a softener

The problem: scale, spots and soap that won't lather

Hardness is mostly dissolved calcium and magnesium.^[source] Hard water leaves white scale in kettles, water heaters and showerheads, spots on glassware, and soap scum in tubs. It's mainly a nuisance and an equipment problem. USGS classifies water by how much hardness it carries, measured as calcium carbonate:^[source]

Are wells around here hard?

Some are, some aren't. Data on hardness in local private wells is limited, because the big county well datasets don't report it. One useful snapshot comes from three USGS monitoring wells in Union County, whose single samples measured 30.5, 132 and 151 mg/L. That's soft at one well and hard at the other two.^[source]

Three wells can't describe a county, and your well may differ from your neighbor's. The point is that local groundwater covers the whole range, so neither "wells are always hard" nor "water around here is soft" holds for your well without a test.

Likely causes

• The rock. Groundwater dissolves calcium and magnesium from the minerals it passes through, so hardness depends on what your well is drilled into.^[source]
• Your own treatment. A calcite acid neutralizer works by dissolving calcium carbonate into the water, so it raises hardness. If you have one for low pH, test hardness after it, not just from the raw well.
• Iron mistaken for hardness. Orange or black deposits aren't hardness. They're iron and manganese, which a softener isn't designed to handle.

How testing works

North Carolina's required new-well test covers magnesium but not calcium or total hardness, so your new-well report can't give you a hardness number.^[source] Our guide to new-well test results shows what is on the report. To get your hardness:

• Add total hardness to a certified-lab panel through our well water testing service, along with iron, manganese and pH. Those three affect what kind of softener, if any, makes sense.
• If you have a neutralizer, sample after it as well as from the raw well.
• Use our softener check tool once you have a number to see where you land.

Treatment: when a softener makes sense

A water softener uses ion exchange to swap calcium and magnesium for sodium or potassium. When your test shows moderately hard or harder water and you're dealing with real scale, it's the standard fix. Look for a model certified to NSF/ANSI 44 and check it in NSF's listings before you buy.^[source] Our water softeners page covers sizing, salt and upkeep.

• Soft or near-soft well: a softener usually isn't worth it. We'll say so.
• Moderately hard to hard, with scale problems: a softener sized to your measured hardness, household size and flow is reasonable.
• Hard plus iron, manganese or low pH: those usually get treated first, with the softener placed after them. The order matters.

When to bring in a pro

If scale is building up in your water heater or on fixtures, test hardness before you buy. A softener ties into your main line, needs a drain for regeneration and sits in a specific spot in the treatment order. Here's how installation works.

Softeners need salt and an annual check of the valve and resin. A Care Plan bundles that with a yearly hardness retest.