To find the best under-sink water filter without separate faucet, we tried 30+ different options on the market and tested them for water production capacity, longevity, flow rate, and durability. After days and months of hard-work, here are our top picks:
Here are the best under sink water filters without separate faucet you can buy in 2025:
- Highest Water Production Capacity: PUREPLUS WFS5300A
- Easy To Install: Frizzlife SK99-NEW
- For Low Pressure: Waterdrop TST-UF
- Durable: Waterdrop WD-AMS08
- Fastest Water Flow: Pentair 4005450
- Smallest Water Production Capacity: AO Smith AO-MF-ADV
| 6 Best Under Sink Water Filters Without Separate Faucet | ||
|---|---|---|
Highest Water Production Capacity | PUREPLUS WFS5300A | |
Easy To Install | Frizzlife SK99-NEW | |
For Low Pressure | Waterdrop TST-UF | |
Durable | Waterdrop WD-AMS08 | |
Fastest Water Flow | Pentair 4005450 | |
Smallest Water Production Capacity | AO Smith AO-MF-ADV | |
Highest Water Production Capacity: PUREPLUS WFS5300A
- Powerful – the 2.5GPM max flow rate
- Space-saving – the no-reservoir design & dimensions of 13.7 x 4.5 x 4.5 inches
- Long-lasting - the 22,000-gallon capacity
- None
Whether you're a big family or a crowded office, the PUREPLUS WFS5300A can easily provide enough drink water for all without waiting.
The major reason is its incredible capacity of 22,000 gallons - which is the largest option in the market - for a whopping 5-year use.
It is IAPMO-certified for the maximum flow rate of 2.5GPM at 60 PSI - three times more powerful than the conventional model. And, it can trap 0.5-micron large particles, heavy metals, and up to 99% chlorine in the water.
The best part? It is extremely compact and space-saving. The no-reservoir design allows this water filter to keep a modest size to fit nicely under a small sink.
| PUREPLUS WFS5300A Specifications | |
|---|---|
Capacity | 20,000 Gallons |
Material | food grade Lead-Free plastic |
Flow Rate | up to 2.5GPM at 60PSI |
Purification Method | Activated Carbon |
Highlight Features | the 2.5GPM max flow rate the no-reservoir design & dimensions of 13.7 x 4.5 x 4.5 inches the 22,000-gallon capacity |
We love the all-around size and the highest water production capacity of the PUREPLUS WFS5300A as the best low-range under-sink water filter option on the market today.
Easy To Install: Frizzlife SK99-NEW
- Easy to install – including all the tools for DIY installation & good instructions
- Quick to replace – the twist-in design
- Sturdy – the 200,000-time of 60PSI water hammer tested bottom cap
- The hoses and adapter could be longer
- Bulky
When purchasing the Frizzlife SK99-NEW, you don't need to put any extra expense on tools for installation because the water filter includes it all.
Compared to other options we tested, this one is easy enough for inexperienced users to try DIY installation. The twist-in design is also a brilliant feature, making the replacement so quick within just 3 seconds.
Sturdiness is another highlight of this upgraded version. It is leak-free, crack-free, and features stronger bottom caps that pass 200,000 times of aggressive water hammer test.
| Frizzlife SK99-NEW Specifications | |
|---|---|
Capacity | 10,000 Gallons |
Material | Plastic |
Flow Rate | 2 Gallons Per Minute |
Purification Method | Carbon Block, Ion Exchange |
Highlight Features | including all the tools for DIY installation & good instructions the twist-in design the 200,000-time of 60PSI water hammer tested bottom cap |
If you need something sturdy, easy to install, and quick to replace, we highly recommend the Frizzlife SK99-NEW
For Low Pressure: Waterdrop TST-UF
- Great performance at low water pressure
- Crack and leak prevention - reinforced housing and thicker sealing rings
- Big and bulky
As under-sink water filters work by utilizing water pressure, not gravity, to push water through the filtration system, most of them only function well at high water pressure.
But don't quickly be disappointed if the water pressure in your home is so low because we still have one great option for you. This is the Waterdrop TST-UF!
It can work well with 15 PSI and still ensures a stable flow rate at 1.59GPM, meaning that it can fill an 8-ounce cup in only 2.3 seconds. The water-filtering ability is similar to other picks in this review.
For further crack and leakage prevention, it’s equipped with reinforced housing and thicker sealing rings.
| Waterdrop TST-UF Specifications | |
|---|---|
Capacity | 12 months or 2600 gallons |
Material | 304 Stainless Steel |
Flow Rate | 1.59 GPM |
Purification Method | activated carbon |
Highlight Features | the 304 stainless-steel housing reinforced housing and thicker sealing rings good performance at 15PSI |
If you’re looking for the best under-sink water filter for low pressure, our top pick is the Waterdrop TST-UF
Durable: Waterdrop WD-AMS08
- 5x longer service life - the premium 1.6-thick 304 stainless-steel
- Leakage prevention - the improved dual sealing rings
- The instructions should be more specific
When it comes to durable and affordable under-sink water filters, the Waterdrop WD-AMS08 is our solid pick due to the premium 1.6"-thick 304 stainless-steel construction and the improved dual sealing rings.
This allows the unit to resist low temperature better and prevent cracks effectively. The upgraded thickness in material also allows it to last 5 times longer with no corrosion or abrasion.
The 1.6GPM flow rate easily meets daily water needs.
| Waterdrop WD-AMS08 Specifications | |
|---|---|
Capacity | 8,000 Gallons |
Material | 304 Stainless Steel |
Flow Rate | up to 1.6 GPM |
Purification Method | Activated Carbon |
Highlight Features | the premium 1.6"-thick 304 stainless-steel the improved dual sealing rings |
We’re thoroughly impressed with the durability of the Waterdrop WD-AMS08
Fastest Water Flow: Pentair 4005450
- Practical – a timer
- Fast water flow – 2.2GPM
- The battery placement is odd
If you know a 3000-gallon capacity under-sink water filter is enough for your needs and you want the fastest option, pick the Pentair 4005450. It steadily delivers up to 2.2 GPM with no impact on the water pressure.
Unlike those reverse osmosis units, this water filter takes up far less room under the sink, so you don't have to give up the space.
We pretty much like the timer, which tells you when to replace the filter. What a handy feature!
| Pentair 4005450 Specifications | |
|---|---|
Capacity | 3,000 gallons or 1 year |
Material | Carbon block |
Flow Rate | 2.2 Gallons Per Minute |
Purification Method | Carbon block with lead reduction media |
Highlight Features | a timer 2.2GPM |
The Pentair 4005450 is rated the fastest water flow in its field, which comes in handy for big families or large offices
Smallest Water Production Capacity: AO Smith AO-MF-ADV
- Ideal for short-term use - The 784-gallon capacity
- Cost-efficient – low filter-replacement expense
- Trustworthy – satisfying the NSF/ANSI 42, 43 and 401 +P473 standards
- The adapter feels cheap
The AO Smith AO-MF-ADV will be the perfect choice for short-term house/apartment tenants.
It’s easy to take on and off, requires no plumbing, and takes up little space under the sink.
Importantly, it is rated to 784 gallons or 6 months with very low filter-replacement expense. The maximum water flow is 1.5 GPM, which is suitable for daily water needs of a four-member family. It also meets all the standards of NSF/ANSI 42, 43 and 401 +P473 to be a reliable product.
| AO Smith AO-MF-ADV Specifications | |
|---|---|
Capacity | 784 gallons or 6 months |
Material | Plastic |
Flow Rate | 1.5 gallons per minute |
Purification Method | Advanced Carbon |
Highlight Features | The 784-gallon capacity low filter-replacement expense |
While most other brands try to provide under-sink water filters with the largest capacity possible, this is one of the very few that comes with small water production capacity.
How To Choose The Best Under Sink Water Filter Without Separate Faucet?
Types Of Filters
The types of under-sink water filters are varied, ranging from a complex multi-stage system to a simpler attachment for an existing water line and faucet. In general, there are three options:
How they work | Advantages | Disadvantages | |
Carbon activated filters | Remove contaminants will chemically bonded and eliminated when water flows through the filters | Affordable | Not as effective as higher-end types of filters |
Ultrafiltration (UF) | Trap contaminants and debris using an empty fiber membrane | Easy to install Able to keep good minerals | Not as effective as RO systems Require to replace the system frequently |
Reverse Osmosis (RO) | Featuring a membrane with tiny pores to only allow water particles to pass through | The most effective (able to remove 1,000+ contaminants) | Remove healthy minerals Bulky Struggling to install |
Notes:
Carbon activated filters are varied in the effectiveness – meaning that each filtration level only removes certain numbers of contaminants, so you should learn about this thoroughly before purchasing.
Longevity & Capacity
No under-sink water filter lasts forever. They require periodic replacement. A basic rule of thumb is the larger the capacity, the longer the filtration system lasts. But take note that large-capacity filters are often bulky.
The longevity ranges of water filters are varied from 6 months to 5 years, therein, 1-3 years are the most popular. A long-lasting option normally comes with a higher upfront cost.
If you want to find the most cost-effective options, consider these two things:
- The upfront cost
- How long does the filter last before replacement?
- The cost per replacement
Divide the cost per replacement by the total years of lifespan; the lower the result, the more cost-effective.
Flow Rate
The flow rate – which is measured in gallons per minute (GPM) - defines the speed that water is dispensed from the faucet.
The more the filtration levels, the higher the flow rate and the faster the speed to fill a glass of water. From that point, RO systems are the slowest and carbon activated filters are the fastest.
The common ranges of flow rate when it comes to under-sink water filters are 0.8-2 GPM.
Which Brands Make The Best Under Sink Water Filter Without Separate Faucet?
Frizzlife
Though Frizzlife is quite young in the water filter industry, their products pleasantly impress us for the quality and performance. They set themselves apart from the competition for affordable prices, sustainability, durability, and efficiency.
Waterdrop Filter
One of the world-leading brands for water filters, Waterdrop is outstanding for its strong R&D team and strict manufacturing progress to ensure it meets all the international standards like UL, NSF, UPC, etc. They were the Reddot Design Award Winner 2020.
Pentair
Established in 1966, it's undoubted that Pentair produces the best water filters with exceptional quality and functionality. They have been the most reliable options of worldwide customers for safer and more sustainable solutions to enjoy water.
FAQs
Are the under sink water filters better?
Yes, they are. Under-sink water filters deliver cleaner drinking water and improve the tastes significantly as they work more effectively at eliminating contaminants than the older versions.
How do I install an under sink water filter?
Do under-sink water filters remove the most contaminants?
Yes, they do. Under-sink water filters are considered as the best for contaminant removal capabilities without clogging. Additionally, they do the job discreetly to not be an eyesore.
Can heavy metals be filtered out of drinking water?
Yes, they can. Modern water filtration systems feature 2 to 5 stages of filter for superior performance to the old-schooled models, meaning that they can effectively remove heavy metals like mercury, arsenic, and lead.
How often should I change the under sink water filter?
Most residential-grade water filters require replacement every 6-12 months while the commercial-grade options should be changed every 4-6 months.
Conclusion
With a greater variety of under-sink water filters available these days than ever before, our team has narrowed down your search by doing all the legwork (like researching, testing, and analyzing the top models available).
We tried to make this review as detailed and comprehensive as possible to assist you to pick the best under-sink water filter without a separate faucet more easily. Hopefully, you like this article. Thanks for reading!
