Is Softened Water Safe to Drink?
Your water softener finally stopped the limescale and let your soap lather the way it should. Then someone mentioned that softened water has extra sodium in it, and now you are eyeing the glass in your hand a little differently.
Here is the straightforward answer from a company that has been building water softeners and filtration systems for over 30 years: softened water is safe to drink for the large majority of people. The sodium it adds is a small fraction of what you already get from food. For a few groups it does matter, and the fix is simple and affordable.
Let's look at the actual numbers.
Key Takeaways
Safe for Most Adults
How Much It Adds
Who Should Be Careful
The Smartest Setup
Where Does Sodium in Your Drinking Water Come From?
Sodium reaches your tap from four main places:
- Natural mineral deposits. As groundwater moves through soil and rock, it dissolves sodium along the way. Background levels vary widely from one area to the next depending on local geology.
- Municipal water treatment. Some treatment plants use sodium-based chemicals during disinfection. These amounts are usually small, often under 20 mg/L.
- Road salt and agricultural runoff. In colder climates, winter road salt seeps into groundwater over time. Fertilizers can also push sodium higher in nearby wells.
- Home water softeners. For most homes with a softener, this is the biggest source. During ion exchange, the process a softener uses to strip out hard minerals, calcium and magnesium are swapped for a smaller amount of sodium. Picture trading a heavy winter coat for a light jacket: the bulky minerals leave, and a little sodium takes their place.
If you have a softener, it is almost always the main reason your drinking water carries extra sodium. So how much does it actually add?
How Much Sodium Does a Water Softener Actually Add?
A water softener adds about 7.5 mg of sodium per liter for every grain per gallon (GPG) of hardness it removes. That figure is the Water Quality Association's industry rule of thumb. Hardness itself is just the amount of dissolved calcium and magnesium in your water, as the USGS defines it, and it is measured at home in grains per gallon. The higher the number, the harder your water and the more sodium gets swapped in.
In over three decades of designing ion exchange systems, our team has found that most homeowners badly overestimate this number. Here is what it really looks like:
| Your Water Hardness | Hardness Level | Sodium per 8 oz Glass | Daily Total (8 Glasses) |
|---|---|---|---|
| 5 GPG | Slightly Hard | ~9 mg | ~72 mg |
| 10 GPG | Moderately Hard | ~19 mg | ~152 mg |
| 15 GPG | Hard | ~28 mg | ~224 mg |
| 20 GPG | Very Hard | ~37 mg | ~296 mg |
| 25 GPG | Extremely Hard | ~47 mg | ~376 mg |
To put that in perspective, here is how a glass of softened water stacks up against everyday foods:
| Food or Drink | Sodium Content |
|---|---|
| 1 glass of softened water (15 GPG) | ~28 mg |
| 1 large egg | ~62 mg |
| 1 glass of milk (8 oz) | ~100 mg |
| 1 slice of bread | ~130 mg |
| 1 tablespoon of ketchup | ~150 mg |
Is Softened Water Actually Safe? What Health Guidelines Say
For most healthy adults, yes, softened water is safe to drink. The sodium it adds is a small share of your daily intake. The CDC recommends keeping sodium under 2,300 mg a day for teens and adults, and notes that too much sodium can raise blood pressure and the risk of heart disease and stroke.
Even with very hard water at 20 GPG, drinking eight glasses of softened water adds roughly 296 mg of sodium to your day. That is about 13% of the CDC's 2,300 mg figure, and most of us take in far more sodium from food than from water.
Sodium in drinking water is not federally regulated the way contaminants like lead are. Instead, the EPA covers it through a drinking water advisory on sodium, a non-enforceable guideline that suggests sodium stay at or below 20 mg/L for people on very restricted (500 mg per day) sodium diets.
The bottom line: if you are a healthy adult with no sodium restriction, softened water is perfectly fine to drink every day.
Who Should Watch Their Sodium in Water?
Softened water is safe for most people, but those with high blood pressure, kidney disease, or a doctor-prescribed sodium limit, plus parents preparing infant formula, should account for the sodium a softener adds and consider an under-sink reverse osmosis system for drinking and cooking water.
A few groups should pay closer attention:
- People with high blood pressure or heart disease. The American Heart Association recommends no more than 1,500 mg of sodium a day for people with high blood pressure. When every milligram counts, the sodium from softened water is worth factoring in, especially with very hard water.
- Anyone on a sodium-restricted diet. If your doctor has asked you to stay under 1,500 mg a day, you will want to know what your softener is contributing. Use the hardness table above to estimate it.
- People with kidney disease. When kidneys are not working at full capacity, the body has a harder time clearing excess sodium, so anything that adds to the daily total is worth tracking with a doctor.
- Parents preparing infant formula. Babies have immature kidneys that handle sodium less efficiently than adults do. If you mix formula with tap water, use water that has not been softened or that has been filtered through a reverse osmosis system.
If any of these fit you, you do not have to give up your softener. You just need a way to cut sodium at the one or two taps where you drink and cook.
Want low-sodium water without losing your softener?
Crystal Quest's under-sink reverse osmosis systems remove 96-98.5% of sodium right at the kitchen tap, engineered and assembled in the USA.
4 Ways to Reduce Sodium in Your Drinking Water
If the sodium in your softened water concerns you, here are four proven options, ranked by how well they work and how practical they are:
| Method | Sodium Reduction | Convenience | Best For |
|---|---|---|---|
| Reverse Osmosis | 96-98.5% | Very high, filters at the tap | Drinking and cooking water |
| Potassium Chloride | Prevents sodium being added | Easy, just swap your softener salt | Keeping your current softener |
| Salt-Free Conditioner | No sodium added at all | High, no salt to buy | New installs or sodium-sensitive homes |
| Distillation | ~99% | Low, hours per gallon | Small volumes only |
Reverse Osmosis: The Most Effective Option
A reverse osmosis (RO) membrane has pores so small, around 0.0001 microns, that dissolved sodium ions cannot pass through. Think of it as a screen door at the molecular level: water molecules slip through while sodium stays behind. A good under-sink RO system removes 96-98.5% of sodium along with dozens of other dissolved contaminants.
For the full range of options, see our complete guide to reverse osmosis.
Potassium Chloride: The Simple Swap
Instead of filling your softener's brine tank with sodium chloride (regular salt), use potassium chloride pellets. The softener works the same way through ion exchange, but it adds potassium instead of sodium, a mineral most people do not get enough of. The trade-off is cost: potassium chloride runs roughly three to four times more per bag than standard softener salt.
Salt-Free Conditioner: Zero Sodium From the Start
Salt-free water conditioners take a different approach entirely. Rather than exchanging ions, they restructure the hard minerals so they cannot stick and form scale, without adding anything to your water. Crystal Quest's Salt-Free Water Conditioner prevents scale while keeping your water completely sodium-free. Our guide to salt-free conditioners explains how they compare to traditional softeners.
Distillation: Effective but Impractical
Distillation boils water into steam and collects the condensate, leaving sodium and other dissolved solids behind. It removes about 99% of sodium, but it takes hours to make a single gallon, which makes it impractical for everyday drinking water.
The Best Setup: Pair Your Softener With an Under-Sink RO System
If you want soft water throughout the house and low-sodium water to drink, the smartest move is a two-system setup: a water softener to protect your plumbing and appliances, plus an under-sink RO system at the kitchen tap for drinking and cooking.
Here is why the combination works so well:
- Your softener handles the whole house. It keeps hard water scale out of your pipes, water heater, dishwasher, and washing machine, which extends the life of every water-using appliance.
- Your under-sink RO handles drinking water. It strips out the sodium the softener added, along with dozens of other dissolved contaminants. You only need RO at one or two taps, which keeps the cost down.
- Installation order matters. Always place the softener before the RO system in the water line. Softened water protects the RO membrane from mineral buildup, which extends its life and cuts maintenance.
This is the setup our specialists recommend to customers every day. A Whole House Water Softener paired with a Thunder 1000C Under-Sink RO gives you complete coverage: soft water for your home, purified water for your glass. Both are designed, engineered, and assembled in our USA facility under an ISO 9001 certified quality management system.
Not sure which combination fits your home? Compare your choices in our water softener vs. water conditioner guide, or tell our water specialists about your home and they will recommend the right pairing.
How to Check the Sodium Level in Your Water
Before changing anything, it helps to know how much sodium is already in your water.
If you are on municipal water: request your utility's annual Consumer Confidence Report (CCR). Every public water system in the US has to publish one each year, and it lists sodium alongside other measurements. Many utilities post the CCR online, or you can start from the EPA's drinking water resources.
If you are on well water: your water is not covered by municipal testing, so a laboratory analysis is the only reliable way to know your baseline. Crystal Quest's Well Water Test measures sodium along with other key parameters. For sample-collection tips, see our guide on how to test your water at home.
What the numbers mean:
| Sodium Level | What It Means |
|---|---|
| Under 20 mg/L | Below the EPA's advisory level, no concern for most people |
| 20-100 mg/L | Moderate, worth monitoring if you are on a sodium-restricted diet |
| Over 100 mg/L | Consider treatment, especially for drinking and cooking water |
Keep in mind these are your baseline levels before softening. Your softener adds sodium on top of whatever is already there. To estimate your total, add the sodium-per-liter figure from the hardness table to your baseline reading.
Get sodium-free drinking water and keep your softener.
Crystal Quest's under-sink reverse osmosis systems take out 96-98.5% of sodium at the kitchen tap, designed and assembled in the USA.
Frequently Asked Questions About Softened Water and Sodium
Can you drink softened water every day?
For most healthy adults, yes. The sodium a typical softener adds is a small share of the CDC's recommended daily limit of 2,300 mg. People with high blood pressure, kidney disease, or a sodium-restricted diet should filter their drinking water with a reverse osmosis system to remove the added sodium.
How much sodium does a water softener add?
A water softener adds about 7.5 mg of sodium per liter for each grain per gallon (GPG) of hardness it removes. For a home with 15 GPG hard water, that works out to roughly 28 mg per 8 oz glass, less than a quarter of the sodium in one slice of bread. Use the hardness table above to estimate your own amount.
Does reverse osmosis remove sodium from softened water?
Yes. Reverse osmosis is the most effective home method for removing sodium, with rejection rates of 96-98.5%. The membrane's tiny pores (about 0.0001 microns) block dissolved sodium ions while letting purified water through. An under-sink RO system paired with your softener gives you soft water for the house and low-sodium water at the tap.
Do standard water filters remove sodium?
No. Carbon filters, including pitcher and faucet-mount models, do not remove sodium because the ions are too small for carbon media to capture. Reverse osmosis is the most effective and practical option for home sodium removal, taking out 96-98.5%. Distillation also works but is far slower.
Is softened water bad for people with high blood pressure?
Softened water is not inherently harmful, but it does add sodium that people managing high blood pressure should account for. The American Heart Association recommends no more than 1,500 mg of sodium a day for that group. With very hard water (20+ GPG), an under-sink reverse osmosis system is a simple way to remove the sodium your softener adds from the water you drink and cook with.
Can I use potassium chloride instead of salt in my softener?
Yes. Potassium chloride works the same way as softener salt through ion exchange, but it adds potassium instead of sodium. It is a good option if you want to keep your current softener and avoid adding sodium, though it costs roughly three to four times more per bag than standard salt.
Is softened water safe for plants and pets?
The added sodium is usually fine for pets in normal amounts, but sodium-sensitive houseplants and aquariums can react to it over time. For plants, pets on sodium-restricted diets, or fish tanks, use water from an unsoftened line or run it through a reverse osmosis system first.
