Softened water is safe to drink for most people, but sodium content and a few specific situations matter
Water softeners replace hard minerals (calcium and magnesium) with sodium through a process called ion exchange. The water that comes out is safe to drink for the vast majority of households. However, the sodium added during softening can be a concern for people on sodium-restricted diets, infants under six months old, and those with certain health conditions. If you fall into one of these groups, you have straightforward options to manage it.
The safety question is really about sodium levels and who is drinking the water. A typical water softener adds between 100 and 300 milligrams of sodium per liter, depending on how hard your incoming water is. For context, the FDA recommends limiting sodium to 2,300 milligrams per day for adults. A glass of softened water (8 ounces) usually contains 25 to 75 milligrams of sodium—less than a slice of bread.
Key Takeaways
- Softened water is safe to drink for most adults and children over six months old because the sodium added is minimal compared to daily dietary intake.
- People with high blood pressure, heart disease, or kidney disease should talk to their doctor about softened water, since they may need to limit sodium intake.
- Infants under six months should drink unsoftened water or bottled water because their kidneys cannot process sodium the way older children and adults can.
- If you want to avoid sodium in softened water, install a reverse osmosis filter or a separate tap that draws from unsoftened water for drinking and cooking.
- The taste and mineral content of softened water are different from hard water, but neither version poses a safety risk for the general population.
Who should avoid drinking softened water
Infants under six months old should not drink softened water. Their kidneys are still developing and cannot regulate sodium the way older children and adults do. If your home has a water softener and you have an infant, use bottled water for formula and drinking, or install a bypass line so unsoftened water reaches the kitchen tap. Once a child is six months old, softened water is generally safe.
People with certain medical conditions should check with their doctor before regularly drinking softened water. This includes anyone with high blood pressure, congestive heart failure, kidney disease, or cirrhosis of the liver. These conditions often require limiting sodium intake, and softened water adds to the daily total. Your doctor can tell you whether the amount is a problem for your specific situation or whether you should use an alternative water source for drinking.
People on strict sodium-restricted diets prescribed by a doctor (usually below 1,500 milligrams per day) may want to avoid softened water as a primary drinking source, though the amount added is usually small enough that it does not push someone over their limit. Again, your doctor or dietitian can advise based on your total sodium intake from all sources.
How much sodium does a water softener actually add
The amount of sodium added depends on how hard your water is before softening. Harder water requires more salt in the softening process, so it ends up with more sodium. Water hardness is measured in grains per gallon (GPG) or parts per million (PPM). A softener regenerates (recharges) when it has removed a certain amount of hardness, and that regeneration uses salt.
In practical terms, if your water is moderately hard (around 10 to 15 GPG), a glass of softened water contains roughly 50 to 100 milligrams of sodium. Very hard water (20+ GPG) might add 150 to 300 milligrams per liter. You can find out your water hardness by asking your water utility, testing it yourself with a kit, or having a water company test it for free. Once you know the hardness level, you can calculate the sodium addition or ask your softener installer for an estimate.
Options if you want to avoid sodium in softened water
The simplest option is to install a reverse osmosis (RO) filter under your kitchen sink. These filters remove sodium and other dissolved solids, producing water that is softer than tap water but without the added sodium. RO filters waste some water (typically three to four gallons for every gallon of filtered water), but they are inexpensive to install and maintain. Replacement filters cost $30 to $100 per year.
Another option is to install a bypass line on your water softener so that one tap—usually the kitchen sink—draws unsoftened water directly from the main line. This gives you hard water for drinking and cooking while the rest of the house gets softened water. Hard water is safe to drink; it straightforward tastes different and can leave mineral deposits on fixtures and in appliances. Some people prefer the taste of hard water and choose this route anyway.
A third option is to use bottled water for drinking and cooking if you prefer not to install additional equipment. This is more expensive over time but requires no installation or maintenance. If you choose this route, check the label to confirm the bottled water is low in sodium (usually under 50 milligrams per liter).
Taste and mineral differences in softened water
Softened water tastes noticeably different from hard water. It feels slicker on your skin and hair because there are fewer minerals to interfere with soap. Some people like this; others find it feels soapy or unpleasant. The taste is often described as flat or slightly salty, though the sodium content is too low to actually taste salty to most people.
Hard water contains calcium and magnesium, which some people believe are beneficial minerals that the body needs. However, the body gets calcium and magnesium primarily from food, not from drinking water. Softened water does not deprive you of these minerals in any meaningful way. If you are concerned about mineral intake, your diet is the relevant source, not your tap water.
What the water utility and health agencies say
The U.S. Environmental Protection Agency (EPA) does not regulate water softeners or set limits on sodium in softened water. However, the EPA does require water utilities to notify customers if sodium levels exceed 30 milligrams per liter in the public water supply. Most water softeners add less than this amount, though very hard water can exceed it.
The American Heart Association recommends limiting sodium to 2,300 milligrams per day for most adults, with lower limits for people with high blood pressure. A typical glass of softened water fits comfortably within this limit. State and local health departments generally consider softened water safe for the general population, though they often recommend unsoftened water for infants and advise people with sodium-restricted diets to consult their doctor.
Testing your softened water for safety
If you want to know the exact sodium content of your softened water, you can test it. Many water utilities will test your water for free or a small fee. You can also buy a home test kit for $20 to $50 that measures sodium, hardness, and other minerals. Some water softener companies offer free testing as part of their service.
Testing is most useful if you have a medical condition that requires sodium restriction or if you are concerned about the quality of your softener's output. A test tells you the actual sodium level so you can make an informed decision about whether to drink it, use an RO filter, or choose another option. If you install a reverse osmosis filter, testing before and after confirms that it is working properly.
Frequently Asked Questions
Can I give softened water to my baby?
No, not before six months old. Infants under six months have immature kidneys and cannot handle the sodium in softened water. Use bottled water or unsoftened water for formula and drinking. After six months, softened water is generally safe, though you may still prefer bottled water or unsoftened water if you want to be cautious.
Does softened water cause high blood pressure?
The small amount of sodium in softened water does not cause high blood pressure in healthy people. However, if you already have high blood pressure or heart disease, your doctor may recommend limiting sodium from all sources, including softened water. Talk to your doctor about whether softened water fits within your sodium limit.
Is softened water bad for plants or pets?
Softened water is safe for most pets and plants. Some plants are sensitive to sodium and may show signs of stress if watered exclusively with softened water over a long period. If you notice yellowing leaves or poor growth, switch to unsoftened water or rainwater. Pets have no problem with softened water in their drinking bowls.
What if I do not know how hard my water is?
Contact your water utility and ask for a water hardness report, or request a free test from a local water softener company. You can also buy an inexpensive test kit at a hardware store. Knowing your hardness level helps you understand how much sodium is being added and whether it matters for your situation.
Does reverse osmosis remove all sodium from softened water?
Yes, reverse osmosis filters remove sodium and most other dissolved minerals, producing very pure water. The trade-off is that RO systems waste water and require filter replacements every 6 to 12 months. They are effective if sodium is your main concern.