In this installment of The Upgrade, we dive into reverse osmosis filtration for the kitchen, its benefits and hidden costs — plus which households should invest in the technology, and who can skip it.
I’ve lived in some places with questionable drinking water. One town issued a notice that the municipal water supply had experienced a sewage incident. Another had an arsenic problem. I’ve also lived on well water, with concerns of contamination from nearby agricultural fields.
My solution used to be buying five-gallon jugs of spring water. But that was costly and a hassle, so six years ago, I switched to an under-sink reverse osmosis (RO) filter for my drinking and cooking water.
Under-sink RO filters work like this: water passes through a series of filters, including an RO membrane, which removes dissolved substances — including lead, arsenic, nitrates, forever chemicals, chlorine, fluoride and sediment — down to 0.0001 microns. The cleaned water then comes out through a faucet, installed near the sink.
“Reverse osmosis provides the safest level of drinking water possible,” says international water filtration specialist Andrew D. Daily. “It strips out 100% of bacteria, cysts, dissolved solids, chlorine, rust, viruses and microplastics.”
But RO systems are also a considerable investment. So, we asked a range of health and plumbing experts for their thoughts on who should get an RO system, plus how to pick the right one. Ahead is what they said, how much RO systems cost up front and over time, and whether it’s worth the upgrade.
Upfront Costs of RO Systems
RO water systems range from a few hundred dollars to over $1,000. The good news is that if you have basic plumbing knowledge and are comfortable drilling a hole in your countertop, installing one can be a DIY task. Otherwise, pro installation usually runs upwards of $300, not including add-ons like a refrigerator/ice-maker connection, leak protection, an additional electric outlet and other plumbing modifications.
Operating Costs of RO Systems
The biggest downside to RO systems is that they waste water. For every gallon that comes out of the faucet, somewhere between one-half and four gallons get flushed down the drain through the filtration process. That means if you use 5 gallons of water a day for cooking and drinking, the RO system wastes between 2.5 and 20 gallons.
Over a year, that adds up to between 500 and 8,500 gallons, depending on your RO system. On the low end, that’s only a few pennies more on your yearly water utility bill, but on the high end, it could be close to $100.
- Pro-tip: To reduce water waste, choose an EPA WaterSense-certified system.
Some RO water systems also require electricity. The amount of power they consume varies by model, but usually falls between 20 and 40 watts per hour. Since RO systems typically run for less than an hour a day, even if you live in a place with high electricity rates, they should add only a few dollars a year to your electricity bill.
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Maintenance Costs of RO Systems
Maintaining RO systems is an easy DIY task, though some people choose to pay a pro to keep track of it for them. Expect to spend roughly the following for DIY maintenance:
- Filters: $30-$100, every six to 12 months
- RO membrane: $25-$60, every couple of years
- Holding tank sanitizer: $20 every year
- Checking tubing and fittings for leaks: $0, every year
Daily recommends buying only name-brand filters, even though they’re more expensive. “Name brands follow strict regulations,” he says. ”Generic China-based deals often do not provide the same protection.”
Longevity
A quality RO system can last 10 years or longer with proper maintenance. “Many parts, including filters, membranes, faucets and tanks can be replaced individually,” says plumbing expert Danielle Smith. “Once a system gets older, though, replacement may make more sense than repeated repairs.”
What Long-Term Users Say
“The biggest thing for me is convenience,” says environmental and wellness expert Helen Christoni, who has an AquaTru system. “We use water all day long, drinking it, cooking with it and filling water bottles. Once installed, it just became part of my kitchen and my family’s daily health.”
Herman Hartanto, founder of Tampa Fast Home Buyer, has a Waterdrop G3P600 in his kitchen ($429 retail). It’s a tankless model, a feature he appreciates since it takes up minimal cabinet space. He also likes the display with real-time reports on total dissolved solids (TDS) and filter health. His only complaint is the occasional noise it generates. “The pump that draws the water on demand makes quite loud noise, which I can feel clearly at night when everything is silent,” he says.
Personally, I’ve used two RO filter systems. My first one was an iSpring, which I chose because of its affordability. It worked well, but like Hartanto, I found the pump noisy (even though mine had a water-holding tank). My second one, which I’ve only recently installed, is a Waterdrop X12 Pro, which I chose to upgrade to because of its water-saving efficiency, ability to add calcium and magnesium back into the water, clear display and range of other premium features. So far, I’ve found it to be quiet, efficient, and free of quirks (though at $1,400 off-sale, the price is a bit of a shocker).
Alternatives to an Under-Sink RO Water Filter
Depending on what type of contaminants you have in your water, there are several alternatives to an under-sink RO water filter:
- Under-sink ultrafiltration (UF) systems reduce microorganisms, retain dissolved minerals, and cost significantly less, but don’t remove a full range of dissolved chemicals, heavy metals and other contaminants.
- Countertop and pitcher filters, like the Waterdrop CT01 and PT-72W Pitcher, improve taste and reduce chlorine, rust and sediment, but generally don’t remove many other contaminants.
- Whole-house systems treat all of a home’s water, instead of just one faucet and are best for removing rust and sediment, softening water and making it taste better. Some, like Clearsource, also remove viruses and microplastics.
- Countertop RO systems, like the AquaTru Carafe and the Waterdrop M6SL, are great for renters and students, as they offer the same filtration benefits of under-sink models, but without the need for permanent installation.
How to Choose an RO System
- Have your water tested to identify which contaminants you need to address, then look for a system specifically certified to remove them.
- Between models, compare water efficiency, space requirements, water pressure, display options, electricity and drainage requirements, flow rate, replacement filter costs, warranty and parts availability.
- Decide whether you need helpful minerals, like calcium and magnesium, added back to the water after it’s filtered.
- Consider upgrade features like a UV lamp, filter-life indicators, water-quality and flow-rate sensors and leak detection.
- Decide between tank vs. tankless. Tankless filters usually cost more and require electricity (some tank models do as well), but they take up less space, often provide higher flow rates and reduce concerns about stagnant stored water.
“Find out what’s in your water before buying anything,” says Smith. “Don’t choose a system based only on how many stages it has or how many contaminants the box says it removes. Instead, start with your water and choose the system around what you actually need.”
Who Needs an Under-Sink RO Water Filter?
If you’re worried about contaminants like microplastics, arsenic, lead, forever chemicals, pesticides and pharmaceuticals, then an RO filter is a good choice.
“Water quality can vary tremendously depending on where you live, and even your home’s plumbing can affect what ultimately comes out of your faucet,” says Christoni. “Reverse osmosis addresses such a broad range of contaminants, and with an under-sink system, that purified water is available all day long without having to think about it.”
For Daily, the biggest reason to invest in a RO system is microplastics. “The amount of microplastics found in human brains, blood and organs have been increasing yearly,” he says. “Although there is not enough information to prove a detrimental effect on our health, many of my clients choose a cautious approach to water treatment.”
Otherwise, Daily says that RO filters are overkill in most U.S. cities, where tap water is generally considered safe. Even in Mexico, where water is often contaminated, he usually recommends sticking with under-sink ultrafiltration systems, since they’re a fraction of the cost, don’t waste water and don’t require power or space for a reservoir.
Is the Upgrade Worth the Cost?
If you’re currently buying bottled water, then yes, an RO system will soon pay for itself. But, otherwise, it really just depends on what you want to remove from your water. If you have arsenic, nitrates, salts, microplastics, fluoride, sulfates and other dissolved solids (TDS), RO systems are a great solution.
Otherwise, a less-expensive ultrafiltration system might be a better choice. Either way, having an under-sink filtration system is a good way to ensure your family has access to clean water, both on a daily basis and after flooding events and other natural disasters that contaminate city and well water.
So, are you ready for the upgrade?
About the Experts
- Andrew D. Daily specializes in in-home water filtration in Mexico City and is the founder of Water Filters CDMX.
- Helen Christoni is an environmental and wellness expert specializing in indoor air and home health, and chief business officer at Ideal Living.
- Danielle Smith is CFO and COO at Gotelli Plumbing Company, a multi-generational, woman-owned company based in Northern California.
Sources
- Dr. Eric Roy is a water scientist with more than 20 years of experience. He currently works as head of science at Culligan.
- In-house experts at Waterdrop filters also shared insights for this article.
