Best Under-Sink Filters | Carbon & Reverse Osmosis. 2022 Buyer’s Guide
What is the best under-sink filter? The first thing to consider is the type of water filtration. Actually, much depends on what problem you are dealing with. To remove free chlorine from water, you can use inexpensive activated-carbon filters. The other type of filtration system, reverse osmosis, solves a wider range of tasks. These devices remove common contaminants like metal ions and aqueous salts, sodium, copper, chloride, and lead. Reverse osmosis filters can also reduce the amount of radium, sulfate, magnesium, nitrate, and phosphorous in the water. Also, we recommend opting for a product that softens the water and removes odors.
Secondly, you will want to buy an under-sink filter that is easily installed and requires little maintenance. Carbon-activated filters connect easily to any cold water supply through a push-to-connect fitting system. As for RO filtration systems, they require a more complicated installation. In this case, the best option is a product that includes a faucet attachment. We believe that the iSpring RCC7AK 6-Stage Under Sink Reverse Osmosis Filter System meets these criteria best.
Why have we chosen it? The device is made by a Georgia-based company, iSpring Water Systems, that has been producing reverse osmosis water filtration systems for about two decades. This is a trusted manufacturer specializing in residential, commercial, whole house water systems, kitchen faucets and fittings.
How Do Under-Sink Filters Differ from Each Other?
Noticed a stale, metallic taste in your water recently? You're not alone: One comprehensive three-year study found that more than 200 unregulated chemicals were found in the tap water of 45 US states.
Between 2004 and 2009, the Environmental Working Group (EWA) found 316 contaminants, like industrial solvents, refrigerants, weed killers, and rocket fuel in public water through an analysis of over 20 million tap water sources.
An under-sink filter provides just one line of defense against some of the most common water contaminants. Not only does poor-quality drinking water taste funky, but it can also threaten you and your family's health.
Utility companies do their best to limit contaminants, but they are stretched too thin with limited research and analysis sources. Just because a water source is "legal", doesn't mean it comes without serious health concerns for the average consumer.
Under-sink water filters are point-of-use filtration systems that are installed right where you need to access clean water. These filters remove many common contaminants, including chlorine, pesticides, herbicides, heavy metals, and VOCs.
Different Types of Under-Sink Filter Technologies
There are three main types of under-sink filters: conventional style, simple, and reverse osmosis.
Attached to your cold water line, a traditional under-sink filter allows water to pass through a separate faucet. You'll still have access to unfiltered water through your primary faucet. However, some drilling will be required to attach the additional faucet.
By contrast, a simple under-sink filter treats water directly from the cold water line that's later pushed through the regular faucet - installation only takes minutes! Since they filter all water, simple under-sink filters tend to have less longevity than a traditional-style set-up.
As the most difficult system to install, a reverse osmosis (or RO) filter flushes away contaminants while dispensing pure water. Featuring a very fine membrane, the water works through several layered filters to remove sediments both large and small.
Through filtering out extremely small particulate matter, RO systems are recommended for the most sensitive uses. With less sodium, parasites, and bacteria, RO helps those who suffer from high blood pressure, low fertility, nerve damage, and even cancer. It mitigates the risks of a child's exposure to brain-damaging contaminants, too.
All under-sink filters are installed under your sink, meaning you won't have to sacrifice vital countertop space. On the whole, under-sink filters have a larger capacity than countertop versions, consisting of more complex filters and cartridges that require infrequent replacement.
Moreover, all under-sink filtration uses in-house generated water pressure to siphon off contaminants. These systems tend to involve more heavy-duty installation, like drilling, screwing, and wrenching.
Review of the Best Under-Sink Filters
Below, we have drawn up a list of some of the best under-sink filters on the market. Each filter has been compared by factors like the filtration system, unique features, and water capacity. Their prices range from $70 to $215 depending on the technology used. The simplest and low-cost option uses a carbon-block activated filter while more sophisticated models employ the reverse osmosis filter system.
1. iSpring RCC7AK 6-Stage High Capacity under-sink Filter | Best Reverse Osmosis Filter System
Offering a six-layer alkaline demineralization layered filtration system, the iSpring is designed to restore the natural mineral balance while freeing your water from some of the most common contaminants.
The iSpring utilizes reverse osmosis to convert impure water in clean, clear, and sediment-free drinking water free of up to 99 percent of 1,000 harmful contaminants. Arsenic, asbestos, calcium, sodium, and more are removed through this natural process.
At the final stage of filtration, the iSpring uses water softening to produce a more natural, clean taste than standard five-stage filters. The result is slightly acidified water with a pH of 7.0 and below.
The ultra-fine mesh filters remove contaminants down to 0.0001 microns in size. Users state that the taste is on-par with high-end bottled water brands.
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iSpring: Check the current price
2. Express Water Reverse Osmosis Water Filtration System | Best for the Money
Just like the iSpring, the Express filter utilizes reverse osmosis to provide water 99.99 percent free of lead, chlorine, fluoride, nitrates, calcium, arsenic, bacteria, and much more.
Specially engineered to fit under standard-sized sinks, the Express is quick to install and use right away. The filter is even covered by a one-year "no questions asked" warranty provided through the manufacturer.
Unlike the iSpring, the Express doesn't require you to refill or manually activate the water filter. The filtration system automatically fills your water tank with high-quality drinking water for a no-fuss experience.
Moreover, the Express features a leak detection system that immediately shuts off water flow when unwelcome moisture is detected. More experienced users can even customize their filter with additional fittings, including UV water filtration, alkalinizing systems, and more.
Keep in mind that, while the iSpring comes pre-fitted with a water alkalizer, the Express doesn't.
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Express water: Check the current price
3. Waterdrop 15UA Under Sink Water Filter System | Best Compact
Looking for the most compact, lightweight, and budget-friendly filter? The Waterdrop will work perfectly for you.
Using a five-stage filtration process, the Waterdrop uses carbon-block activated filter media to ensure efficient and safe filtering. The lead- and BPA-free material ensures a more reliable system that removes 99 percent of chlorine, heavy metals, chemical contaminants, and fluoride.
Unlike the iSpring and Express, the Waterdrop automatically filters out large particles to prevent scale buildup. Even though it's cheaper, the filters are designed to last longer than more expensive competitor products.
Using the power of your in-house water pressure, the Waterdrop doesn't require any additional electricity to function. Developed for both household and commercial use, the Waterdrop is sufficient for high-intensity use all year round.
On average, the Waterdrop only adds $15 per year, or 4 cents per day, to provide safe and contaminant-free drinking water. The tested full flow rate is 2.0 gpm at 60 psi.
Of course, the Waterdrop doesn't use reverse osmosis to treat your water - it may not be as effective as other modern RO systems. That said, it connects easily to any cold water supply through a push-to-connect fitting system.
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Waterdrop: Check the current price
