Still surveying for the best under sink water filter for your home?
You’re at the right place.
I’ve done all the hard work for you with my years of expertise and experience.
Trust me, what I am going to show you is the real deal about under sink water filtration system that fits your needs.
I’m not some random bloggers that simply grab a few water filters from online marketplaces and call it a day (I have seen many from just a few simple Google-searches).
Even with my years of expertise in the water treatment industry, I still spent a few days to research, survey, analyze, compare (in-depth), and filter to come out with this best under sink water filtration system list that I’m satisfied with.
Why Use an Under Sink Water Filtration System
Under-sink is among the most popular types of water filtration system sought by families, especially those with more family members.
The reasons why many people are preferred under counter water filter are:
- Strong filtration performance
- Under counter placement
- Last longer (higher capacity)
- More choices of filtration system
- Fast water filtration rate
Strong Filtration Performance
One of the main reasons why people are using under sink water filter at home is because of its strong filtration performance in getting rid of harmful contaminants in tap water.
Its high filtration power is achieved by the flexibility in utilizing multiple filters in a stages filtration process to remove a wider range of water contaminants.
Because the under sink system can fit in multiple stages of filters, allow it to have more features like UV disinfection, remineralization, and taste improvement.
If you want the best water filtration for your home, you’ll have to go for an under sink filtration system (most of the time).
Under Counter Placement
When comes to home and kitchen-related things, space and appearance are two important elements to consider.
The advantage of using an under sink system is it will not occupy any sink top space like a countertop system, especially if your kitchen is not big.
Also, some families have certain theme color or design for their kitchens, so by having an under counter water filter hiding in a covered space, it will not affect the theme aesthetically.
Last Longer (Higher Capacity)
Another advantage of under sink water filtration system is its higher filtration capacity, allowing it to last longer and reduce your maintenance frequency for filter replacements.
More Choices of Filtration System
There are more choices of filtration system for the under-sink setup, such as reverse osmosis, ion-exchange, ultraviolet (UV), activated carbon, sediment, ultrafiltration (UF), and ionization.
If you prefer to use a filtration system other than sediment and activated carbon, under sink water filter is your go-to pick.
Fast Water Filtration Rate
Except for the Reverse Osmosis system, all the under sink water filtration system comes with high water filtration rate, saving your time in filling up your water bottle or cup.
Top 10 Under Sink Water Filter (At a Glance)
Before we moving to the buying guide and detailed reviews, let’s have a look at the top 10 list of the carefully picked under sink water filtration system first:
- APEC Top Tier Supreme RO-PH90 – Best Overall
- Waterdrop WD-G3-W Tankless RO – Best Tankless RO
- APEC WFS-1000 3-Stage Under Sink – Best Value (Non-RO)
- Home Master TMAFC-ERP Artesian – Best Water Efficiency (RO)
- iSpring CU-A4 Compact System – Best Ultrafiltration (UF)
- iSpring RCC7AK-UV Deluxe Under Sink – Best RO with UV
- Express Water RODI10D Deionization RO – Best Water Purity
- Express Water ROALK5D Alkaline RO – Best Alkalinity
- Woder 10K-Gen3 Water Filter – Best Long-lasting
- Culligan US-EZ-4 EZ-Change Water Filter – Best Budget
How to Choose the Best Under Sink Water Filter (Buying Guide)
Instead of just showing you a list of water filter, I also want you to learn how to select the most suitable under sink water system for your home and family.
Let’s start with the 5 important factors in considering an under sink water filter:
- Contaminants to getting rid of
- Types of filtration technology
- Filtration performance
- Additional features
1. Contaminants to Getting Rid of
Now we are talking about filter out harmful contaminants from tap water, but what exactly are those?
Of course, you don’t need to know every single impurity in your tap water, but it’s good for you to at least know the quality of your water in brief, like whether it contains a significant amount of certain contaminants like lead, mercury, fluoride, arsenic, pesticides, etc.
The most accurate way to know your tap water is to get some water sample and send to the certified lab for testing.
Otherwise, you may read the report from your water supplier or do some testing with TDS meter for water hardness estimation.
2. Types of Filtration Technology
Once you know about the quality of your tap water, it’s time to decide the filtration technology required.
If your water is hard, like more than 120 ppm (or 120 mg/L), it’s best to use Reverse Osmosis system to greatly reduce the total dissolved solids (TDS) in water.
If your water is soft, like less than 60 ppm (or 60 mg/L), Reverse Osmosis system is a bit overkill, and I’ll suggest you go for a combination of sediment filter and activated carbon block. Additional ultrafiltration (UF) can be added to the filtration system for stronger protection (optional).
If you’re using well water or poor-quality water source that is vulnerable to viruses, a water filtration system with ultraviolet (UV) lamp is strongly recommended.
If your tap water contains excess amount of cations (eg: magnesium, calcium) or anions (eg: nitrate, arsenic), then Ion-exchange (IX) system is an effective method to remove those ions.
Also, most of the time (if not all), you’ll need a sediment filter as a front layer of filtration to block the larger particles (eg: rust, sand, stone, etc.) and an activated carbon filter to treat chlorine taste and odor, so these two are like the defaults in a multi-stages water filtration system.
3. Filtration Performance
Alright, after you’ve decided the type of filters that you need, it’s time to dive in deeper on the filtration performance required.
For instance, if you’re getting an under sink Reverse Osmosis system, how many stages of filtration you want or need?
For instance, a basic setup would be a 3-stage Reverse Osmosis system:
An upgraded version would be a 4-stage Reverse Osmosis system:
Or a max performance 6-stage Reverse Osmosis system:
Theoretically, it can go more than 10 stages of filtration and you can also find those in the marketplace, but I wouldn’t recommend you to get a water filtration system that goes beyond 6 stages of filtration (excluding additional features like mineralization).
That’s too much and the excess filters are redundant with no real contribution.
4. Additional Features
Are you a fan of alkaline or mineral water?
If you’d like to have more of certain minerals in your filtered drinking water, you can consider getting a multi-stages water filtration system with mineralization stages to add minerals into the filtered water.
With the flexibility of the under sink water filtration system, you can build an ideal water filtration system that is dedicated to your home.
Before getting too excited with the filtration performance and features, what’s your budget by the way?
It’s the fact that price tag is always an important deciding factor in purchase consideration, so take your time and think about your budget.
How much money are you willing (or capable) to pay for a water filtration system for your family members’ health?
If budget is not a big concern for you, I’ll recommend you to get the best water filtration system for your family, it’s definitely worth the investment.
If your budget is tight, no worry, just get a great water filtration system within your budget.
Anyway, getting a water filter is already a right step towards more saving in the long term.
Top 10 Best Under Sink Water Filter [Reviews]
Here are the reviews of each under sink water filter and the reasons why they were picked and included in this top 10 list.
1. APEC Top Tier Supreme RO-PH90 Reverse Osmosis Water Filter [Review] – Best Overall
- Effectively removes 99% of contaminants in tap water
- Strong filtration performance with 6 water filtration layers
- High flow rate at 90 GPD
- Produce high-purity mineralized drinking water with calcite remineralization.
- Improved water taste by raising the pH level and neutralizing acidity in the water
- More details..
The APEC Top Tier Supreme RO-PH90 is a powerful Reverse Osmosis system with remineralization feature that provides pure and tasty water to your family.
It’s capable to remove 99% of contaminants including chlorine, lead, bacteria, fluoride, viruses, heavy metals, arsenic, and more.
The system comes with 100% lead-free and metal premium designer faucet and FDA Certified JG food grade tubing for safe and contamination-free drinking water.
Besides, it includes a 100% US-made high-purity calcium carbonate mineralizing water filter to enhance pH in the water, which is great for those who are looking for alkaline water.
In terms of security, the APEC Top Tier Supreme RO-PH90 water filter is WQA certified and comes with 2 years manufacturer warranty and lifetime support to provide you with peace of mind.
2. Waterdrop WD-G3-W Tankless RO Water Filtration System [Review] – Best Tankless Reverse Osmosis
- Effectively remove 99% of major contaminants
- Tankless design
- An intelligent water filtration system
- Quick and easy installation
- Quick 1-turn filter change
- Space efficient
- Fast water filtration rate of 400 GDP with an internal pump
- Efficient wastewater to clean water ratio of 1:1
- Beautiful design
- Smart faucet
The Waterdrop WD-G3-W is an innovative high-performance tankless Reverse Osmosis water filtration system that’s capable to remove most contaminants in tap water with filtration size down to 0.0001um.
With the combination of sediment filter, activated carbon, and reverse osmosis technology, this water filtration system can effectively remove a wide range of contaminants such as chlorine taste and odor, heavy metals (eg: lead, mercury, copper), carcinogens (eg: cadmium, chromium), microorganisms (eg: cysts, bacteria), Inorganic contaminants (eg: arsenic, fluoride), organic contaminants (benzene, lindane), total dissolved solids (TDS), turbidity, and more.
Here’s the breakdown of the Waterdrop 3-stage water filtration system:
Moreover, the tankless design takes up less space and protect the system from secondary pollution like bacteria growth.
Also, with the help of an internal pump, this tankless RO system is producing pure water at 400 GPD rate, which is about 5 times of most Reverse Osmosis system in the market, no more waiting time for filling up your water bottle or cup.
The water efficiency is another factor to consider this tankless Reverse Osmosis system. With wastewater to clean water ratio of 1:1, it can save a lot of water and reduce your water bill.
Note: You need to flush the whole system for at least 30 minutes or 8.5 gallons of water after installation. Alternatively, you may flush and wait until the blue light on faucet stop flashing.
3.APEC WFS-1000 Under Sink Water Filter [Review] – Best Value (Non-RO)
- Great water filtration performance
- Fast water filtration rate of 1 gallon per minute (GPM)
- Utilize 3 filtration layers to remove major contaminants like chlorine taste and odor, rust, sand, solids, VOCs, and more
- Made in the USA for quality assurance
- Comes with FDA certified JG food grade tubing and lead-free chrome faucet for water safety.
- All the 3 filter cartridges can last up to 12 months.
- Backed by a one-year satisfaction guarantee and lifetime support from APEC.
The APEC WFS-1000 3-stages under sink water filtration system is a fast water filter (or called hi-flow water filter) that deliver clean drinking water to your faucet quick to shorten the waiting time to fill up your cup or bottle.
Here’s the breakdown of the APEC 3-stages under sink water filtration system:
All three high-capacity filter cartridges can last up to 12 months. The longer filter life also means fewer replacements and lower maintenance cost for using this under sink filtration system.
4. Home Master TMAFC-ERP Artesian with Permeate Pump [Review] – Best Water Efficiency (RO)
- Consists of 7 stages of water filtration and enhancement which capable to remove 99% of contaminants like chemicals, sediments, heavy metals, and inorganic compounds
- Come with a built-in non-electric permeate pump (made in the USA) to reduces water waste up to 80% and increases water production by up to 50%
- Patented Full Contact technology adds calcium and magnesium minerals twice during the purification process
- Long-lasting and easy-to-change filters
- Replace filters only once a year
- More details..
The Home Master Artesian Full Contact with Permeate Pump uses 7 stages of water filtration and enhancement to remove up to 99% of chlorine, chloramines, heavy metals, pharmaceuticals, dissolved solids, and other contaminants.
Its innovative design eliminates the most common problems like canister filter housing leaks, high water waste, slow flow rate, service challenges, and slightly acidic water.
Besides, the Reverse Osmosis systems use catalytic carbon filtration media in the carbon pre-filters to treat the chloramine, which normal carbon filters are unable to effectively remove it.
Also, some Reverse Osmosis water filtration systems produce highly pure but slightly acidic water, and when the acidic water sits in the storage tank, the acidic water dissolves some of the rubber bladders and causes storage tank degradation which affects the taste of the water.
In contrast, the Home Master Artesian Full Contact with Permeate Pump prevents storage tank degradation from occurring with its patented ‘Full Contact’ remineralization system. This system balances the water’s pH level by adding a small amount of calcium and minerals (30-60 mg/L combined) through a natural process when the water travels to the storage tank and when the water travels to the faucet.
Compared to other Reverse Osmosis system, the Home Master TMAFC-ERP Artesian Full Contact uses a modular “all-in-one” design where the filter is incorporated into the filter housing to avoid the possibility of the microorganisms, sediments, and biofilm accumulate in the filter housing and cause leaking.
Last but not least, the Home Master TMAFC-ERP Artesian Full Contact is made in the USA and backed by a 5 years limited warranty.
5. iSpring CU-A4 Ultrafiltration Water System – Best Ultrafiltration (UF)
- Effectively removes up to 99% of harmful contaminants like chlorine, lead, bacteria, arsenic, giardia, volatile organic compounds (VOCs), and more
- Retain essential minerals in the water
- Compact size with no water tank
- No wastewater
- Simple installation and maintenance
- CU-A4 Easy-Twist Cartridges make filter replacement quick and easy
- All components comply with ANSI/NSF standards and FDA for quality assurance
The iSpring CU-A4 is a 4-stage compact water filtration system with Ultrafiltration (UF) and KDF/GAC technology to remove a wide range of harmful pollutants in tap water while keeping the essential minerals for great taste and alkaline balance.
Here’s the breakdown of the 4 progressive filtration stages:
The water filtration system is tested against ANSI/NSF standards 42 (chlorine taste and odor, particulates), 53 (lead, asbestos, VOCs), 401 (pharmaceuticals, pesticides, germicides), and P472 (PFOS, PFOA) for water quality and comply strictly with FDA standards.
6. iSpring RCC7AK-UV Reverse Osmosis Water Filter [Review] – Best RO with UV
- The water filter system contains 7 different stages of water filtration and UV sterilization to remove up to 99.99% of contaminants, including arsenic, mercury, fluoride, chlorine, hormones, asbestos, bacteria, viruses, giardia, microorganisms, and more
- The existence of UV sterilization stage makes RCC7AK-UV the perfect solution to purifying water sources containing excessive microorganisms (eg: water from wells, lakes, and streams).
- The Alkaline Remineralization (AK) filter restores useful minerals and produces alkaline-balance water
- Good water filtration rate of 75 GPD
- Transparent 1st stage housing makes filter inspection easy
- More details..
The iSpring RCC7AK-UV is a 7-stage multi-layered Reverse Osmosis system that is tested and certified by WQA to remove up to 99.99% of harmful contaminants that commonly appear in the city including chlorine, arsenic, fluoride, lead, bacteria, mercury, viruses, giardia, asbestos, hormones, sodium, and more.
All components including filters, tank, tubing, and other water-contacting parts are manufactured to comply strictly with NSF/ANSI standard (58 for Reverse Osmosis) and FDA (CFR-Parts 174).
The Alkaline Remineralization stage restores the right proportion of beneficial minerals and natural taste, and the high-performance UV stage provides an extra level of protection against viruses and microorganism contamination.
The iSpring Reverse Osmosis system also went through rigorous testing for air leaks, pressure, and cycle resistance to maintain the quality and high-performance standard.
The filtration system consists of 7 filtering stages, each one is designed to progressively remove contaminants and improve the water quality:
The combination of both GAC and CTO filters in the 2nd and 3rd stages provide greater protection against harmful chemicals like chlorine than CTO alone.
The iSpring RCC7AK-UV uses an 11 watt UV lamp shielded in a stainless steel housing with a flow sensor switch to control the UV lamp on and off automatically with the water flow for power saving and lengthening the lifespan of the UV lamp.
The UV sterilization stage kills the small percentage of viruses, bacteria, and other microorganisms that could potentially remain in the water after the Reverse Osmosis process.
The Alkaline Remineralization (AK) stage is designed to restore the natural minerals and alkaline balance of the water. The red mineral stone portion of the AK filter adds back healthy minerals including not just calcium, magnesium, and more. The calcite portion of the filter neutralizes the pH of the RO water and make the water tastes better with the presence of minerals.
The system also includes a lead-free, solid brass faucet with brushed nickel finish for you to mount on the counter to enjoy your clean and healthy drinking water.
For your peace of mind, the entire system is backed by a 1-year money-back guarantee, a 1-year manufacturer warranty, and iSpring’s lifetime technical support.
7. Express Water RODI10D Deionization Reverse Osmosis Water Filter – Best Water Purity
- Effectively removes 99% of water pollutants like chlorine, fluoride, arsenic, nitrate, lead, bacteria, calcium, VOCs, and more
- Fast water filtration rate of 100 GPD
- Quick and simple installation
- Comes with emergency leak stop detector
- Deionized water for aquarium’s setup
The Express Water RODI10D is a 6-stage Reverse Osmosis water filtration system with deionization technology to hugely reduce total dissolved solids (TDS) and harmful contaminants in tap water.
Here’s the breakdown of the 6 stages of filtration layers:
Moreover, the system also has a high filtration rate of 100 GDP and a leak stop valve to protect your property from water leakage.
8. Express Water ROALK5D Alkaline RO Water Filtration System [Review] – Best Alkalinity
- Removes 99% of Bacteria, Viruses, Heavy Metal, Chlorine, Radium, Lead, Arsenic, Fluoride, and more harmful contaminants
- Up to 20% more oxygen than regular water
- The Active Mineral Technology adds Calcium, Magnesium, Potassium and other minerals into your water
- Quick and simple installation
- More details..
The Express Water ROALK5D consists of 5 stages of water filtration and 5 stages of mineralization, giving you clean drinking water with useful minerals like potassium, calcium, magnesium, and more.
Here’s the breakdown of the 10-stages express water filter system:
The filtered water is also a great source of antioxidants with up to 20% more oxygen.
For the accessories part, the Express Water Filter System ROALK5D comes with a fast flow rate faucet with 0.8 GPM and a 4 gallons (3.2 gallons net water capacity) water storage tank and tank stand.
9. Woder 10K-Gen3 Under Sink Water Filter [Review] – Best Long-Lasting
- Remove up to 99.9% lead, chlorine, chromium 6, mercury, carcinogens, VOCs, heavy metals, turbidity, odor and bad taste, and more contaminants from tap water
- Super-high capacity filter which lasts up to 10,000 gallons of filtered water or 3 years
- A high water flow rate of 2 GPM
- Tested by independent laboratories to ANSI standards
The Woder 10K-Gen3 Water Filter is a high capacity direct-connect under sink filter that can effectively remove chlorine, bad taste and odor, lead, and other contaminants for a long period of time.
The Woder filter use microparticles to contain more filtering ingredients so that it can stay effective for a longer time compared to other filters.
As it’s a direct flow-through filter, all the essential minerals like calcium, magnesium, potassium, and more are kept while filtering out the harmful contaminants.
Do take note that It’s only suitable to be used for municipally treated water.
10. Culligan US-EZ-4 Under Sink Water Filter [Review] – Best Budget
- The RC-EZ-4 filter is tested and certified by NSF International for the reduction of sediments, chlorine taste and odor, chloroform, cyst, lead, mercury, VOCs, turbidity, perfluorinated chemicals (PFOA & PFOS), and more
- The EZ-change replacement filter cartridge allows you to change the filter easily with the quick-connect fittings
- Comes with a dedicated 100% lead-free faucet
- The RC-EZ-4 filter can last up to 6 months or 500 gallons of water filtration
- Comes with a built-in LED filter life indicator for filter replacement
- High water flow rate at 0.5 GPM
- Interchangeable filter cartridge between RC-EZ-1, RC-EZ-3, and RC-EZ-4 to suit your water filtration needs
The Culligan US-EZ-4 Premium Easy-Change Under Sink Water Filtration System is an affordable single filter system that can remove most of the common contaminants, impurities, and chemicals in your tap water.
It fit easily under the sink due to compact size, suitable for kitchen with limited under-sink space.
The filter replacement process is fast and easy with its twist-on and twist-off filter mechanism and built-in quick-connect fittings.
Summary (Comparison Table)
Here’s the comparison of the top 10 best under sink water filtration system:
|Name||Stage||Flow Rate||Best for||Price|
|APEC Top Tier RO-PH90||6||90 GPD||Overalll||Show|
|Waterdrop WD-G3-W||3||400 GPD||Tankless RO||Show|
|APEC WFS-1000||3||1 GPM||Value||Show|
|Home Master TMAFC-ERP||6||75 GPD||Water efficiency||Show|
|iSpring CU-A4||4||0.56 GPM||Ultrafiltration||Show|
|iSpring RCC7AK-UV||7||75 GPD||RO with UV||Show|
|Express Water RODI10D||6||100 GPD||Water Purity||Show|
|Express Water ROALK5D||10||50 GPD||Alkalinity||Show|
|Woder 10K-Gen3||1||2 GPM||Long-lasting||Show|
|Culligan US-EZ-4||1||0.5 GPM||Budget||Show|
Here’s the answers for the frequently asked questions regarding under sink water filter:
No. Newly installed system may have residues or cloudiness, which require flushing prior to using.
Once you have installed a new water filter, you need to flush the system for 10-45 minutes or 5 to 10 gallons of water, depending on the water filter.
No worries, It’s normal for the first few times if you are using a water filtration system that contains carbon block filter.
The greyish color is due to the black color carbon block and the black flakes are from the newly manufactured carbon block.
Just open the water tap and flush the system for about 5 minutes and 2-3 times will do.
Because a flow-through water filter (non-RO) will retain the minerals in water which contribute to TDS value, therefore, the TDS reading will not drop much if your tap water is treated and soft.
TDS value is only applicable to estimate the effectiveness of a Reverse Osmosis system.
The answer is no.
I have seen many people used a TDS meter or TDS pen to measure Total Dissolved Solids in their water without knowing what is really being measured.
In short, what TDS meter measured is the electrical conductivity (EC) in water (pure H2O has virtually zero EC), and then times the EC value by a factor between 0.5 to 1 (set by the manufacturer) to estimates the TDS (which is not the real Total Dissolved Solids in water).
For instances, dissolved organic solids (eg: sugar) and microscopic solid particles (eg: colloids) are not measurable by the TDS meter because they do not affect the water conductivity significantly.
The accurate way to measure the actual TDS in water is to evaporate the water and then weighing the dissolved residue left.
Not absolutely but is recommended if it’s a highly reputable brand in term of product safety, quality control and customer support.
As we discussed earlier, the important parts of considering a water filter system are about the material of the components, where the components are manufactured, and the functionality of the filter system.
So more importantly, choose a water filter system which all its components are manufactured by reputable companies with strict material control and strict quality control (eg: US-based manufacturers).
Not really. For example, a water filter company bought all the low-quality components from elsewhere and assembled in the USA, the company is allowed to say the water filter is “Made in USA”, but this doesn’t justify the product quality and safeties.
What you really need to know is where the components (which used to build the water filtration system) are manufactured. For instance, if all the components are made in the USA and assembled in Thailand, then the water filtration system is considered safe.
The answer is no, but it’s recommended to have NSF certified for all components that have contact with water (especially for smaller brands).
NSF is a certification system and not a quality control system, so it can’t guarantee the filter performance in the long run and the quality of your filter when it’s manufactured (since thousands of filters are being manufactured and shipped to customers directly without going through NSF).
You can measure the pressure drop by installing pressure gauges before and after the filter.
When the filter cartridge is new, run the water filtration system and write down the difference of pressure reading (let’s say 2 psi). Then measure again after a few months, you’ll notice the pressure difference is increasing, let’s say to 7 psi.
When the difference of 2 pressure gauges reading reach about 15, it’s time to change the filter cartridge (or wash if it’s washable).
For safety wise, any filter cartridge that is not washable should change every 1 year (maximum) except sediment filter which required to change more frequently (2-4 times a year depending on water quality).
While for the RO membrane, the lifespan is about 2 years since it gets washed constantly.
No, RO water is simply the purest drinking water. There’s no solid scientific proof or research shows that RO water is bad for you.
Have you found the best under sink water filter for your home already?
I hope you did, trust me, anyone from the above top 10 water filter list is worth to get for your family, it is just which one is more suitable for your requirements.
Back to you, which under sink water filtration system are you going to buy for your home?
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