Readily available filtered water is a staple of healthy living. One of the best ways to ensure you are getting the right intake of water each day is to invest in a water filter of some kind. And while there are many to choose from, this guide will talk specifically about the best under sink water filters.

Best Under Sink Water Filter

We’ve done our best to cover the very best in each category and type of under sink water filter system available.

Under Sink Water Filters Comparison

 NameStagesLifeOur RatingAffordabilityToday's Price
The Best Under Sink Water Filter SystemAPEC Top Tier Alkaline Mineral pH+ 6-Stage RO System

Best of The Best Under Sink Water Filter

610,000 Gallons4.9$$$$View Price
Best Selling Under Sink Water Filter SystemAPEC 5-Stage Reverse Osmosis Drinking System

Best Selling Under Sink Water Filter

510,000 Gallons4.5$$$View Price
The Best 4 Stage Under Sink Water FilteriSpring CU-A4 4-Stage Water Filter

Best 4 Stage Under Sink Water Filter

47,500 Gallons4.4$$$View Price
Best 3 Stage Under Sink Water FilterAPEC WFS-1000 Super Capacity 3 Stage Water Filter

Best 3 Stage Under Sink Water Filter

35,000 Gallons4.2$$View Price
Cheapest Under Sink Water Filter SystemCulligan US-EZ Under Sink Water Filter

Cheapest Under Sink Water Filter

11,000 Gallons4.0$View Price

The Best Under Sink Water Filter Reviews

Now that you’ve compared all the systems side by side in our comparison table, let’s take a deep diver into the individual under sink water filter reviews for each product.

The Best Under Sink Water Filter System

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This system truly has it all. First, through six stages of filtration, including a reverse osmosis membrane, this filter brings your tap water to under 10ppm of TDS. Then, it adds beneficial minerals, including calcium and magnesium, as well as adjusts the pH of the water to make it slightly alkaline, using natural calcium carbonate.

This is truly the best drinking water system available in the market today, and it fits directly under your kitchen sink and is easy to install yourself. No plumbing experience necessary!

We also love that this is 100% made in the USA and comes with a storage tank so you always have fresh supply and good water flow speed.

If drinking the safest and purest water possible for your family, there is no other under sink water filter system other than the APEC Top Tier Supreme Certified Alkaline Mineral pH+ High Flow 90 GPD 6-Stage Ultra Safe Reverse Osmosis Drinking Water Filter System (ULTIMATE RO-PH90).

 

Pros
  • Purifies water up to 99.9%
  • Adjusts pH levels to optimal levels
  • Adds beneficial minerals including calcium and magnesium
Cons
  • Slight more expensive than other units
  • Uses more water to flush the RO membrane

The bottom line: If you want the best of the best in water filtration for your drinking water, this is the under sink water filter system for you.

Best Selling Under Sink Water Filter System

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This under sink water filter is a best seller for a reason — it combines the highly effective reverse osmosis filtration system with an affordable price and a small package that fits right under your sink.

Multiple tests of this reverse osmosis system shows it can reduce TDS of your incoming water by as much as 99%. This makes this water filter capable of filtering nearly any water, no matter how contaminated it is.

If you are interested in comparing this to other RO systems, check our our guide on the best reverse osmosis systems.

This water filter is produced 100% in the USA and is guaranteed to use USDA safe materials.

Pros
  • Purifies water up to 99%
  • Great price for highly effective filtration
  • Comes with storage tank
Cons
  • Does not pH adjust water to optimal levels
  • Removes beneficial minerals

The bottom line: If you want to remove all impurities from your water at a great price, this is the right under sink water filter for you.

The Best 4 Stage Under Sink Water Filter

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If you are looking for premium water filtration without the waste water associated with reverse osmosis, then this is the right under sink water filtration system for you.

The iSpring CU-A4 is one of the only water filters in the market to have 4 stages of filtration, down to 0.1 micron without using reverse osmosis. The result is highly pure and filtered water without any waste water for the reverse osmosis membrane.

What’s also so fantastic about this filter is that is gives you unlimited flow of filtered water without a storage tank, which will save you both space and money.

We also love the fact that while this filters out many contaminants in water, it leaves in beneficial minerals such as calcium and magnesium, so there is no need to re-mineralize after filtration, as you would want with RO.

Pros
  • Purifies water up to 99%
  • Great price for highly effective filtration
  • Unlimited flow without the need for storage tanks
Cons
  • Does not remove as much contaminants as reverse osmosis
  • Slightly large compared to other non-RO water filter systems

The bottom line: If you want highly filtered water without going through reverse osmosis, this is the right water filter for you.

Best 3 Stage Under Sink Water Filter

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If your tap water is already reasonably good but you just want to improve the taste, and protect yourself against potential contamination, then the APEC 3 stage under sink water filter is the right water filter for you.

This filter isn’t able to filter out fluoride, lead or other heavy metals. It is best used for safe drinking water to begin with.

The water filters on the system can filter 1,000 gallons before they need a replacement. For most households, this will be every 1-2 years, depending on how much water you consume.

As with the other APEC models on our list, this one is 100% made in the USA and guaranteed to be assembled with safe materials.

Pros
  • Purifies water up to 98%
  • Great price for highly effective filtration
  • Unlimited flow without the need for storage tanks
Cons
  • Does not remove as much contaminants as reverse osmosis
  • Not suitable for contaminated water

The bottom line: If you want great tasting water even if your tap water is completely safe, this is the right water filter for you.

Cheapest Under Sink Water Filter System

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If you are single and just want a basic water filter to improve the taste of your tap water, then you can go with this simple 1 stage water filter from Culligan, a market leader in water filtration.

This water filter is perfect for an apartment building or condominium that already has treated water by the building, but then you can use a small filter to improve the taste further.

Culligan is a market leader in water filtration and you are truly getting great value at the low price for this water filter.

If you find you’re not drinking enough water, a simple water filter like this to improve the taste might be all the motivation you need to establish healthy water drinking habits.

Pros
  • Improves the taste of water
  • Small and easy to install
  • Very affordable
Cons
  • Does not make water safer

The bottom line: If you want to improve the taste of your water for as cheap as possible, this is the right water filter for you.

Under Sink Water Filter System Buying Guide

Before you buy a water filter, there are a variety of factors to consider. The primary purpose of an under sink water filter is to provide water for drinking or for cooking. For that reason, it should be the purest and cleanest water in your house. If you are already using a whole house water filtration system, you could consider simply using a countertop water filter or a water filter pitcher instead of an under sink variety.

Under Sink Water Filter Buying Considerations

When comparing under sink water filters, you’ll want to judge them based on a few key factors, including:

Stages

In general, the more stages a water filter has, the more pure the water will be, as measured by Total Dissolved Solids (TDS). Most filters are sediment filters of various sizes, measured by their ability to filter out contaminants, in microns.

Reverse Osmosis

Sometimes considered a special stage, a reverse osmosis membrane is the smallest micron water filter available in the market today. It produces the most pure water possible, next to using a water distiller at home.

Filter Life

A filter’s life is based on how much water flows through it over time, not by age. Consider how much water you plan to consume, based on your household size and needs. Filters that have a high degree of filtration also tend to need to be replaced more often.

Physical Size

Some under sink water filters are much larger than others, and depending on how much space is available under your sink, it may impact which filtration system is right for you. Some of the RO system with a storage tank will take up much more space than a single stage water filter, for example.

In Conclusion

Getting an under sink water filter is one of the best ways to build healthy water drinking habits by having the best tasting water always available to you. In addition, especially with the higher end units, you can keep you and your family safe knowing that your water is always clean and pure, regardless of mistakes or pollution at your water source.

 

  • Our Rating
4.8