Questions & Answers
St. Louis Hard Water: Frequently Asked Questions
Short, straight answers to the questions St. Louis-area homeowners actually ask about hard water, softeners, cost, and testing.
The short version: St. Louis-area water is hard to very hard, most homes fall between 8 and 19 grains per gallon, a softener is the real fix, and a free in-home test is the honest way to find your exact numbers. Below are fuller answers to the nine questions we hear most.
Where do these numbers come from? The hardness figures below reflect the St. Louis metro's municipal supplies and the private wells common across the surrounding counties, drawing on the U.S. Geological Survey hardness scale and local utility data. Your own water can sit anywhere within those ranges, so treat the figures as the lay of the land and confirm your exact readings with a test.
Is St. Louis water hard?
Yes. Water across the St. Louis metro is hard to very hard. Most of the area runs 8 to 19 grains per gallon, and the U.S. Geological Survey classifies anything above 10.5 grains per gallon as very hard, so much of the region clears that line. The hardness comes from calcium and magnesium the water picks up as it moves through the limestone and dolomite bedrock beneath Missouri. On the standard scale, water above 7 grains per gallon counts as hard and anything above 10.5 is very hard, so most of the metro sits at or beyond that mark.
How many grains is St. Louis water?
Most homes in the St. Louis metro see 8 to 19 grains per gallon. Missouri American Water, drawn from the Missouri and Meramec rivers, generally runs about 7 to 10 grains per gallon, the City of St. Louis system is around 8, and private wells are frequently 15 to 25 grains per gallon or higher. Your exact number depends on your address and whether you are on city water or a well.
Do I need a water softener in St. Charles County?
Very likely yes. St. Charles County water tends to be hard, and the private wells common across the county often run 15 to 25 grains per gallon or more. If you see spotty glasses, scale on faucets, soap that will not lather, or a water heater aging early, a softener will help. The only way to be sure of the right system is a water test.
Is soft water safe to drink?
Yes, soft water is safe to drink for most people. A salt-based softener works by ion exchange, which adds a small amount of sodium to the water in place of the hardness minerals. The amount is modest, but people on a strict low-sodium diet may prefer a reverse-osmosis tap for their drinking water. Salt-free systems add no sodium at all.
Salt vs salt-free softener - which is better?
It depends on what you want. A salt-based softener removes the hardness minerals through ion exchange, giving you true soft water, a slick clean rinse, and the biggest savings on soap and appliances, in exchange for adding salt and using a little water to regenerate. A salt-free conditioner does not remove the minerals; it changes their form to reduce scale, adding no salt, no sodium, and no wastewater, but it does not deliver true soft water or the same soap savings. Choose salt-based for the full soft-water experience, and salt-free for low-maintenance scale control or when you cannot add salt.
How much does a water softener cost near St. Louis?
A whole-house water softener in the St. Louis area typically runs between roughly $1,000 and $3,000 or more, installed. The price depends on the size and quality of the system, how hard your water is, whether you are on a well that needs iron or sulfur removal, and any add-ons like reverse-osmosis drinking water. The honest way to get an exact figure is a free in-home test and assessment rather than a phone quote.
Will a softener help my water heater?
Yes. Hard water leaves scale that coats the tank and the heating element, which makes the heater work harder, use more energy, and often fail before its expected 11 years. Softened water stops new scale from forming, helping the heater hold its factory efficiency and reach its full lifespan. Protecting the water heater is one of the main ways a softener pays for itself.
Why is my water spotty?
Spots on glasses and fixtures are dissolved hardness minerals left behind when hard water dries. The calcium and magnesium stay on the surface as the water evaporates, leaving white specks and film. Rinse aid can hide it for a while, but the only real fix is to reduce the hardness with a softener.
How do I get my water tested?
You can test your water two ways. A do-it-yourself hardness strip from a hardware store gives a rough reading in minutes. For an accurate answer, a proper in-home test measures hardness, iron, chlorine, TDS, and pH at your actual tap and explains what the results mean, and a local specialist will often run one for free. On a well, testing is the only way to know what is in your water, since wells appear on no utility report. If you want a real number to base a purchase on, the in-home test is the one to book.