You should not drink water from a water softener, and most systems include a bypass tap at the kitchen sink for this reason.
Water softeners work by swapping calcium and magnesium minerals for sodium through a process called ion exchange. The water that comes out is softer for washing and cleaning, but it contains added sodium that makes it unsuitable for drinking, cooking, and watering plants. A standard softener raises sodium levels enough that regular consumption can add hundreds of milligrams to your daily intake — a concern for anyone managing blood pressure or on a sodium-restricted diet.
The solution is straightforward: most softener installations include a dedicated bypass line that feeds unsoftened water directly to your kitchen tap. This gives you soft water for laundry and showers while keeping your drinking water in its original mineral state. If your system does not have this setup, adding one is a straightforward plumbing job that costs between $100 and $300.
Key Takeaways
- Water softeners add sodium to water through ion exchange, making it unsafe for regular drinking and cooking.
- A kitchen tap bypass line delivers unsoftened water to your sink while the rest of your home gets soft water.
- If your softener lacks a bypass, a plumber can install one for a modest cost.
- People on sodium-restricted diets, infants, and those with certain health conditions should never drink softened water.
- Softened water can damage plants and is not recommended for watering gardens or outdoor landscaping.
How much sodium does a water softener add
The amount of sodium added depends on how hard your water is. A softener removes hardness minerals by trading them for sodium ions, so the harder your water, the more sodium ends up in the finished product. Water with 10 grains per gallon of hardness (a common level) will gain roughly 100 to 150 milligrams of sodium per liter after softening.
For perspective, the American Heart Association recommends no more than 2,300 milligrams of sodium per day for most adults. If you drank two liters of softened water daily from very hard water, you could be adding 200 to 300 milligrams — a meaningful portion of that limit. For people with hypertension, heart disease, or kidney problems, even this amount matters.
You can request a water hardness test from your local water utility or a water treatment company to find out your specific level. Once you know the hardness, you can calculate the sodium addition or ask your softener installer to provide the figure for your system.
Who should never drink softened water
Infants under six months old should not consume softened water at all. Their kidneys are still developing and cannot handle the sodium load the way adult kidneys can. If you have a softener and an infant in the home, use unsoftened water for formula and drinking.
People with high blood pressure, heart disease, kidney disease, or cirrhosis should avoid softened water unless a doctor has cleared it. The same applies to anyone on a sodium-restricted diet for medical reasons. If you are unsure whether softened water is safe for your situation, ask your doctor — they know your health history and can give you a direct answer.
Pregnant women and nursing mothers should also stick to unsoftened water, since sodium intake during pregnancy and lactation can affect both mother and child. Again, a bypass tap at the kitchen sink solves this problem entirely.
Installing a bypass tap for drinking water
A bypass tap is a separate faucet at your kitchen sink that draws water directly from the main line before it enters the softener. Installation requires running a small copper or plastic line from the incoming water supply to a dedicated tap, then installing a valve to control the flow. The whole job takes a plumber one to two hours.
If you are handy with plumbing, you can buy a bypass kit online for $30 to $60 and install it yourself, though hiring a plumber ensures the work meets code and the connections do not leak. Most plumbers charge $150 to $300 for the full job, including the tap and valve.
Once installed, you will have two taps at your sink: one for soft water (washing dishes, filling the kettle) and one for unsoftened water (drinking, cooking with vegetables). Many people label the unsoftened tap to avoid confusion.
Why softened water damages plants and gardens
Plants struggle with the sodium in softened water. Sodium builds up in soil over time and interferes with the plant's ability to absorb water and nutrients, a problem called osmotic stress. Leaves may yellow or brown at the edges, growth slows, and the plant eventually weakens.
This is especially true for outdoor gardens and houseplants that stay in the same soil for months or years. A single watering with softened water will not kill a plant, but regular use will. If you water your garden or indoor plants, use unsoftened water from a hose connected to the main line before the softener, or collect rainwater instead.
What to do if your softener has no bypass
If you inherited a softener without a bypass tap or your system was installed without one, you have three options: install a bypass, use bottled water for drinking and cooking, or have the softener removed.
Installing a bypass is the most practical choice for most households. A plumber can add one to almost any existing softener in a few hours. If your softener is very old or the plumbing layout makes a bypass difficult, the plumber will tell you upfront.
Bottled water works if you only need a small amount for drinking and cooking, but it becomes expensive and wasteful if you use a lot. Removing the softener entirely is an option only if you are willing to live with hard water throughout your home — which means more soap scum, shorter appliance life, and higher water heating costs.
Testing your water after softening
If you want to know exactly how much sodium your softener is adding, you can have your water tested. Your local water utility may offer free or low-cost testing, or you can send a sample to a private lab for $50 to $150. The test will show sodium levels before and after softening, plus other minerals and contaminants.
This information is useful if you are on a sodium-restricted diet or have a health condition that makes sodium intake important. It also helps you decide whether a bypass tap is enough or whether you need a different treatment method, such as a reverse osmosis filter under the sink for extra protection.
Frequently Asked Questions
Can I drink softened water if I only use a little bit?
Occasional small amounts of softened water are not dangerous for most healthy adults. The risk comes from regular daily consumption. If you accidentally drink a glass of softened water, it will not harm you. But if you are making coffee, cooking pasta, or filling a water bottle from softened water every day, the sodium adds up.
Does a water softener remove other contaminants besides hardness?
No. A softener removes only calcium and magnesium minerals. It does not filter out bacteria, lead, chlorine, nitrates, or other contaminants. If your water has other quality issues, you may need a separate filter in addition to the softener.
What if I cannot afford to install a bypass tap?
Bottled water for drinking and cooking is the cheapest short-term option. A case of bottled water costs a few dollars and lasts several days for one person. Over time, a bypass tap installation pays for itself compared to buying bottled water, but if budget is tight now, bottled water keeps you safe until you can install one.
Is softened water bad for washing dishes or laundry?
No. Softened water is actually better for washing dishes and laundry because it reduces soap scum and allows detergent to work more effectively. The sodium content is not a concern for external use — only for drinking and cooking.
Can I use a pitcher filter instead of a bypass tap?
A pitcher filter like Brita or PUR will remove some sodium, but not all of it. If you are on a strict sodium-restricted diet, a pitcher filter alone may not be enough. A bypass tap or a reverse osmosis filter under the sink is more reliable for people who need to keep sodium intake very low.