Last Updated on May 20, 2021
There are many types of water filtration systems available today. From large countertop systems to whole-house systems, you get a lot of options. But under sink water filters might be the most convenient and cost-effective filter systems of all. Some of our favorites even removed bacteria, cysts, VOCs, and more from our water, providing us with a top-quality drinking experience. And best of all, we didn’t even need to call in a plumber to install them!
But a quick internet search will reveal hundreds of options to choose from. How can you decide which under sink water filter system is the right fit for your home without wasting a ton of money and time testing them yourself? Lucky for you, we already went through the hassle of testing and comparing all the best and most popular ones. We’ve compiled what we learned in the following ten reviews and even took the liberty of picking our top three to recommend in the hopes of saving you time.
A Quick Comparison of Our Favorites
|Best Overall||CuZn UC-200||
|Best Value||Watts Premier 2-Stage||
|Premium Choice||iSpring 6-Stage||
|Woder Water Filtration System||
The 10 Best Under Sink Water Filters – Reviews 2021
1. CuZn UC-200 Under Counter Water Filter – Best Overall
If you’re looking for a complete water filtration system that fits neatly underneath your kitchen sink, look no further than the CuZn UC-200 Under Counter Water Filter. This filter removes all the unwanted impurities in your water, purifying it without removing the minerals that are necessary for your health.
This filter purifies with a three-stage filtration process that removes chlorine, heavy metals, sediment, algae, mold, pesticides, herbicides, bad tastes and odors, and more, leaving you with a healthy, delicious, and pure drinking water. However, it’s only for use with municipal water and not intended for filtering private well water.
A single filter will last you for up to five years or 50,000 gallons of water, whichever comes first. Even better, you can easily install this filter yourself in about five minutes. Everything you need for a standard installation is included, and if you have non-standard piping at the moment, they’ll even send you a non-standard install kit free of charge.
2. Watts Premier 2-Stage Under Sink Water Filter – Best Value
Volatile organic chemicals (VOCs) are estimated to be present in one-fifth of the nation’s water. By using the Watts Premier 2-Stage WP500313 Under Sink Water Filter, you can protect yourself from these harmful chemicals since it removes them completely. But that’s not all this filter system removes. It also filters out lead, herbicides, pesticides, chlorine, and a host of other chemicals. As if that wasn’t enough, this is one of the few filters that removes bacteria and cysts like giardia, entamoeba, toxoplasma, and cryptosporidium. This means it’s usable with private well water.
Considering all that this filter removes, it’s priced very affordably and much cheaper than many alternatives that don’t remove nearly as many harmful contaminants from your water. But it’s not perfect. Instead of filtering the water going to your existing sink, this filter has its own tap that will dispense the filtered water and take up more counter space. And you’ll have to replace the filters every 600 gallons. But considering the peace of mind this filter provides at such an affordable price, we think it’s the best under sink water filter for the money.
3. iSpring 6-Stage Under Sink Water Filter System – Premium Choice
If you want a premium drinking experience every time you reach for the faucet, and you’re willing to pay a bit more for the highest-quality water, our recommendation is the iSpring 6-Stage RCC7AK Under Sink Water Filter System. This advanced filter system uses a six-stage reverse osmosis system to completely purify your drinking water. It removes up to 99% of more than 1,000 harmful contaminants. The list includes things like chlorine, fluoride, arsenic, asbestos, calcium, and more.
While most of the filters we tested simply remove the unwanted impurities from your water, the iSpring filter goes a step further. The sixth stage in the filtration process is an alkaline remineralization filter. This step restores the minerals to your water for balanced alkalinity, providing improved taste and the minerals that are vital for your health.
This system uses its own faucet instead of filtering the water to your main faucet. But it’s designed to be easily installed by the homeowner without the need for professional help. Keep in mind, six stages of filtration can take up a good bit of space under your sink, especially with the 3.2-gallon pressurized tank.
4. Woder WD-S-8K-DC Under Sink Water Filter
If you’re cramped for space under your sink and you’re looking for a compact water filter that won’t take up much room, then the Woder WD-S-8K-DC Under Sink Water Filter is an option worth taking a look at. It’s got just one single-stage filter that can easily tuck into the corner of your cabinet. Best of all, you can easily install it yourself; no plumbing required.
This filter lasts for three years or 8,480 gallons. That’s not the best filter life we’ve seen, but it’s pretty respectable. It’s touted to remove 99.99% of contaminants, which is pretty impressive. However, it’s intended for use only with municipal water sources, not well water. This is because it won’t remove bacteria or cysts; the real harmful contaminants. But it will remove heavy metals, lead, chlorine, VOCs, mercury, and other contaminants while leaving in the healthy minerals to provide a tasty and refreshing drinking experience.
5. Frizzlife MK99 Under Sink Water Filter System
The Frizzlife Under Sink Water Filter System offers an affordable way to start drinking healthier, cleaner water today. It utilizes a two-stage filter that filters down to 0.5 microns. That helps it to remove 99.99% of contaminants, a bold claim. Included in that list are lead, heavy metals, chlorine, VOCs, carcinogens, bad tastes, odors, and much more. However, it doesn’t remove the harmful bacteria and cysts that are often present in well water.
What’s nice about this filter is how easily it installs. It’s supposed to take just three minutes with no plumbing required. Unfortunately, that wasn’t quite our experience. The fittings leaked when we installed it, so we had to re-install it with a better thread sealer than what was included. This was a bit more time-consuming than anticipated, but it still installed pretty easily overall.
It’s recommended that you change this filter every six to eight months. That’s going to add up to a lot more replacement filters over time than some of the other systems we tested with filters that lasted several years between changes. Moreover, the way that this system is installed, it’s difficult to change the filter; a minor oversight but an annoyance, nonetheless.
6. Ecosoft FMV3ECOUS Under Sink Water Filter System
More isn’t always better, but when it comes to filtration it often is. That’s why the Ecosoft FMV3ECOUS Under Sink Water Filter System uses three stages of filtration. This allows it to remove particles, bacteria, and more. Many similar systems don’t remove bacteria, so we were glad to see that this one does. You even get a two-year warranty with this filter, something we didn’t see with most of the other systems we tested.
On the other hand, this one was a pain to install and takes up a lot of under-sink space. The three stages of filtration mean this system is larger than the streamlined single-stage systems. Worse, the included fittings didn’t work with our plumbing. They were 5/8” and should be 3/8” to work with standard plumbing. This meant we had to waste quite a bit of time and money making trips to the hardware store, which increased the overall cost of this filter system. Though we like that this filter removes bacteria, we don’t think it’s worth the extra headache and cost involved.
7. 3M Aqua-Pure 3MFF100 Under Sink Water Filter System
The 3M Aqua-Pure Under Sink Water Filter System seems like a great choice at first glance. It has a three-stage filter system that reduces tastes, odors, lead, cysts, and even some VOCs like benzene. But it doesn’t remove harmful bacteria and the remaining VOCs; something that other much less expensive filters we tested managed to do. For the price, we think this filter’s performance is lackluster.
What we liked about this filter is that it hooks into your main water line and filters the water from your sink faucet, not a dedicated filtered water faucet. But the fittings needed for installation weren’t included. Considering the high price this filter sells for, we were disappointed that we had to make an additional trip to the hardware store and spend even more money just to get this filter installed.
The installation itself was difficult. We have some plumbing experience and were able to get it done. If you have no experience with plumbing though, you might need to call in some professional help.
Our final complaint was the poor filter lifespan. Each one lasts just 12 months; a far cry from the five-year filter life of our favorite filter.
8. APEC WFS-1000 Under-Sink Water Filter System
This three-stage filter system from APEC Water Systems is designed and built in the USA. It comes with a one-year satisfaction guarantee; the same length of time that the filters last. Compared to other filter systems with filter lifespans of up to five years, a one-year filter life isn’t exactly impressive.
This filter system removes chemicals like chlorine, plus bad tastes and odors. But it doesn’t reduce total dissolved solids. It also won’t remove bacteria or cysts, so it’s not a good choice for those on well water. Truthfully, we weren’t impressed with the short list of contaminants that this filter does remove, especially given the expensive price tag. For the price, you can get a filter system that removes bacteria, cysts, VOCs, and more, with a much longer filter life.
9. Culligan US-600A Under-Sink Drinking Water Filtration System
We loved the dirt-cheap pricing of the Culligan US-600A Under-Sink Drinking Water Filtration System. But cheap isn’t always better, as we found out with this filter. Still, the included five-year warranty is better than most that we’ve seen.
This system filters the water coming to your existing faucet. Generally, we prefer this over a dedicated filtered water faucet. However, this filter has a very slow flow rate of just one gallon per minute. Once installed, it slowed down the flow rate of our sink until it was barely usable.
But the worst part was getting this filter installed in the first place! The included tubing is the wrong diameter, which makes it very hard to get it attached to your existing plumbing. It’s going to take several trips to the hardware store and quite a few additional fittings.
Then, when you go to replace the filter, good luck getting the cartridge open! It’s always jammed closed, a major inconvenience considering how often you’ll be changing the filters. They have a lifespan of just 1,000 gallons. Not very impressive compared to some of the other filters we tested.
10. Aquasana AQ-5300+.55 Under Sink Water Filter
We had high hopes for the Aquasana AQ-5300+.55 water filter system. Things started well with a rather simple installation. All the parts we needed were included in the box. But we weren’t thrilled with the filtration of this system. It only removes 77 contaminants compared to the hundreds or even thousands of contaminants that other systems we tested were capable of removing. This filter also doesn’t reduce total dissolved solids. That’s not a dealbreaker, but it’s worth mentioning.
Another downside with this filter system is that the filter cartridges only last for six months each. That’s nothing next to the five years that the filters on some of our favorite systems lasted. What’s worse is that this is one of the most expensive systems we tested! For the price, we expected much better and we don’t recommend the Aquasana system, despite the easy installation.
After weeks of extensive testing and reviews, plus hundreds of gallons of water, we finally settled on three favorite under sink water filters to recommend. Our favorite was the CuZn UC 200. Its three-stage filtration process purifies without removing the healthy minerals. Even better, it’s easy to install by yourself with no professional help needed. And best of all, each filter lasts for up to five years or 50,000 gallons of water, giving these filters the best lifespans of any we tested.
If you’re on a budget and looking for the best value, we suggest checking out the Watts Premier WP500313. This filter is affordably priced but still offers excellent performance. It removes lead, cysts, VOCs, and chlorine. But that’s not all; it’s one of the few filters we tested that also removes harmful bacteria and cysts making it a great option for anyone on well water.
Finally, the iSpring RCC7AK is our premium choice recommendation. It’s more expensive than the other options, but it’s also packed with features like six stages of filtration and an alkaline remineralization filter. Plus, it removes up to 99% of over 1,000 harmful contaminants, providing you with safe, clean, delicious drinking water.
Featured Image Credit: wertinio, Shutterstock
David Slone runs the TapIt Water blog. He first learned about water filtration and the impact it has on the world in college. Ever since that day he has worked towards making the world a better place. He writes to inform you about water filtration, the consequences of plastics, bottled water, and how we can do things better.
He loves to spend time with his beloved wife, 3 kids, and dog when he’s not writing.
- 1 A Quick Comparison of Our Favorites
- 2 The 10 Best Under Sink Water Filters – Reviews 2021
- 2.1 1. CuZn UC-200 Under Counter Water Filter – Best Overall
- 2.2 2. Watts Premier 2-Stage Under Sink Water Filter – Best Value
- 2.3 3. iSpring 6-Stage Under Sink Water Filter System – Premium Choice
- 2.4 4. Woder WD-S-8K-DC Under Sink Water Filter
- 2.5 5. Frizzlife MK99 Under Sink Water Filter System
- 2.6 6. Ecosoft FMV3ECOUS Under Sink Water Filter System
- 2.7 7. 3M Aqua-Pure 3MFF100 Under Sink Water Filter System
- 2.8 8. APEC WFS-1000 Under-Sink Water Filter System
- 2.9 9. Culligan US-600A Under-Sink Drinking Water Filtration System
- 2.10 10. Aquasana AQ-5300+.55 Under Sink Water Filter
- 3 Conclusion