4 Water Filters That Remove Sodium and How to Pick the Best One for You

You may not be able to taste it, but it's possible there is sodium in your drinking water.

"Most people don't consider water when it comes to sodium," says New York City-based dietitian Amy Shapiro, RD, founder and director of the private practice Real Nutrition.

"While the small amounts of sodium in water isn't typically a concern for the general population, it may be more important for certain health conditions," says Mackenzie Burgess, RDN, registered dietitian and recipe developer at Cheerful Choices.

For instance, people with high blood pressure (which includes nearly half of all adults in the United States, per the Centers for Disease Control and Prevention), as well as those with heart disease, people with kidney problems and those who are on a low-sodium diet may have cause to want to limit drinking water that contains sodium, Shapiro says.

"You also would have to be concerned about drinking water and the water you use for cooking beyond your usual concerns of the amount of sodium found in your foods," she says.

Installing a water filter to remove sodium may help you cut back on your salt intake. But not just any filter will remove this mineral — here are the best ones, along with what you need to know about why your water might contain sodium and how to remove it.

When it comes to removing sodium from your water, the best tactic is typically reverse osmosis (RO).

"A water filtration system that uses a physical filtration method is often recommended [when you want to remove sodium from your water], such as reverse osmosis, which actually removes those minute particles," says Riggs Eckelberry, water expert and founder and CEO of OriginClear, a Clean Water Innovation Hub.

Here's why a reverse osmosis filter is more meaningful than just a filter alone: A reverse osmosis filter has multiple layers, as well as a semi-permeable membrane, explains Timothy Dunphy, a water expert at Leaf Home Water Solutions. Pressure sends water through this membrane, per the NSF.

"Because of the pressure, it just lets a portion of the water through," Dunphy says. The water is then split into two streams: wastewater and purified water that's stored in a tank, Dunphy says. The membrane provides a ton of filtration, so that it rejects sodium as well as other minerals and contaminants.

As well as looking for water filters that incorporated reverse osmosis, we sought out options from reputable brands with strong reviews and looked for systems with third-party certification.

Cost can be a prohibitive factor with RO systems. Many are quite pricey, and may potentially require that you hire someone for installation help. This budget-friendly option is made in the U.S. It's also certified by the Water Quality Association (WQA).

It comes with a faucet and food-grade tubing and offers a warranty. Filters last 6 months to a year — many other systems have more short-lived filters. These filters are, of course, essential to the system working, and their cost can add up.

This under-the-sink system has a 4-gallon tank and can produce up to 50 gallons of water per day, per the manufacturer. For heavy water users or large families, that may not be enough. For every 1 gallon of filtered water, there are 3 gallons of wastewater.

Short on space underneath your sink? This tankless NSF-certified RO system might be the right option for you. It'll free up to 70 percent of space underneath your sink, per the manufacturer (leaving room for cleansers, buckets and the other household items that previously occupied the space).

Note that this system contains a carbon block that's made from coconut shells — so, if you have a coconut allergy or intolerance, this system is best avoided.

The Waterdrop reverse osmosis system also comes with a faucet that has a smart display, so you can see useful information like the quality of your water, the total dissolved solids (TDS) and when the filter needs to be replaced.

With this RO system, you'll get a 1:1 wastewater-to-clean-water ratio — that adds up to less waste (and potentially lower water bills) than many other systems. Plus, it offers up to 400 gallons of water a day.

Note that the unit needs to be plugged in, a potential inconvenience if you do not have a plug readily available where the system goes. An accessory kit is required to connect the unit to your refrigerator.

This RO water filter is certified by the WQA and also meets NSF standards. It sits under the sink and comes with a chrome kitchen faucet that shows when filters need to be replaced.

The tank fits 6 liters and fills in less than an hour. Installation is relatively simple — it doesn't require any plumbing.

Renters, those who shudder at the thought of DIY home projects or anyone with limited space underneath their sink may gravitate toward a countertop reverse osmosis system.

This RO system meets NSF/ANSI standards and does not require installation or plumbing know-how to get started. Instead, just find a spot on your counter that's near a power source and plug it in.

This unit has a 1-gallon capacity, but only holds 3 quarts of purified water. That may make it less than ideal for cooking needs. The filters last for 6 months to 2 years (or, between 600 and 1,200 gallons of water). There's an alert when the filters need to be replaced.

The system works fast, generating purified water in just minutes.

There are a few reasons why your water may contain sodium. First, it does naturally occur in groundwater, Eckelberry says. Living by the ocean can also lead to an increase in salinity, Dunphy notes. Contaminants (think: road salt, fertilizer and sewage) can also be a factor.

"There is no drinking water standard for sodium but for those who are on a very low sodium diet they should have no more than 20 mg/liter," Shapiro says. Sodium concentrations in drinking water should be between 30 and 60 mg/L, per the Environmental Protection Agency (EPA) but note that this is just a guideline given because of taste, and not enforceable, per the EPA.

There's another big reason sodium may be present in your water: Water softeners.

"If you have a softening system, that softening system is also going to potentially put some additional sodium into your water," Dunphy says. A softening system is used to transform hard water into soft water.

While hard water is generally seen as undesirable, it doesn't innately present health hazards. Rather, hard water — which contains dissolved elements including calcium and magnesium — makes it hard for soap to lather, creates scaling in pipes and generally "cause[s] numerous problems in laundry, kitchen and bath," per the WQA.

Sometimes you can actually taste the sodium, Shapiro says. But if it could be present in low levels, and not detectible by your taste buds.

One simple step to determine your water's sodium levels: Check with your water providers, Eckelberry recommends. Water treatment plants and public water suppliers are required to make this information publicly available, Dunphy says.

You can also enter your ZIP code in the Environmental Working Group's tap water database, Dunphy says.

Water test kits can be used, Eckelberry says. These can be used if you have private well water; you can find them easily online (Well Water Test Kit for Drinking Water, $35.99). These tests are recommended every 3 to 5 years, Shapiro says.

Here are some key considerations when it comes to purchasing a reverse osmosis system:

As well as the cost of the reverse osmosis system, consider any installation costs that may be required and the lifespan of filters as you'll need to make sure that you're replacing those as needed.

Take a look at the water production of the unit as well, and consider how much water you'll need on a daily basis. Check the water output per day, which is in gallons.

As well, consider the size of the tank: This is how much water is stored for your use. If you use a lot of water, you might use it faster than it's available. But a large tank, which offers more water-on-demand, might take up more space than is reasonable.

Measure your space before purchase, so you can confirm you have enough room for the tank. And, check for any other installation requirements — for instance, one option on this list requires a power source.

Along with being hard on the environment, creating a lot of wastewater through reverse osmosis can lead to a higher water bill.

If you live in the United States, your salt intake is likely higher than it should be.

"As a dietitian, I recommend 2,300 milligrams of sodium per day and less for those on restricted-sodium diets but most people get more than 3,000 milligrams per day mainly from food sources," Shapiro says.

Water isn't a main culprit for salt intake, and you likely don't need to be concerned about the sodium in your water unless you're on a low-sodium diet or have certain conditions. That said, nearly all of us would be wise to reduce our salt intake — here are some salt-cutting tactics:

• ‌Cut down on packaged and prepared foods.‌ That's the real issue, not your salt shaker. About 70 percent of dietary sodium intake is through eating prepared/packaged foods, per the FDA.
• ‌Check the label.‌ When you purchase foods, look at the nutrition facts, and assess how much salt is in products. The goal is 2,300 milligrams a day or under. Then, opt for lower-sodium varieties of packaged goods. That may mean opting for low-sodium soup or unsalted nuts.
• ‌Rinse canned products.‌ This includes beans and canned veggies, which often contain added salt, per the FDA.
• ‌Ask for less salt.‌ If you're dining out, try requesting that salt not be added to your meal or choosing low-sodium options on the menu, per the U.S. Department of Health and Human Services.