Please note: Prices last checked on May 5, 2025. Also, costs were adjusted if a company has provided us with a discount code (short-term sales and discounts requiring some kind of subscription didn’t count). We may also have adjusted annual cost if a manufacturer’s stated filter lifespan appeared unrealistic.
Key Takeaways
Based on our lab testing and comparison of 19 different systems, a good under sink water filter usually costs anywhere between $130 and about $550 upfront, and about $100-200 in annual filter replacements.
A brief summary of our data:
- Upfront price range in our under sink water filter comparison is $86.15 to $1,000+.
- There are good filters in each sub-category: Tank-based ROs, tankless ROs, and regular (non-RO) under sink filters.
- We estimate the average upfront price of tank-based ROs at $275.00, whereas tankless ROs are more costly at $450.00 on average. The average upfront price of regular under sink filters in our comparison is around $190.00, which is the lowest.
- Average annual filter replacement cost for both RO and non-RO systems in our comparison is about $200.00.
- Our top pick tank-based RO system costs $549.00 upfront and ~$200 annually.
- Our top pick tankless RO system costs ~$460 upfront and ~$145 annually.
- Our top pick regular under sink water filter costs $128.00 upfront and ~$175 annually.
How much does a good under sink water filter cost in 2025, and how much do you need to invest if you want a top-performing system? Also, is there really a difference between budget and premium-priced under sink filters? What about reverse osmosis (RO) vs non-RO filtration systems? We’ve tested 19 popular models first-hand, including tank-based RO systems, tankless ROs, and regular (non-RO) under sink water filters, to find the answers to those questions!
Contents
Under Sink Water Filter Cost Overview
Below are the 19 under sink water filters that we examined in our comparison, including their upfront and long-term costs, as well as their key performance metrics.
| Under Sink Water Filter | Cloud RO | Waterdrop G3P600 | Waterdrop X12 | Epic Smart Shield (Incl. Faucet Kit) | Aquasana SmartFlow | US Water Systems All American 5-Stage RO | Home Master TMHP-L HydroPerfection Loaded | APEC ROES-50 Essence | SimPure T1-400 ALK | AO Smith AO-US-200 | Brondell H2O+ Circle | GE GXRQ18NBN | Frizzlife PD600-TAM3 | Culligan US-EZ-4 | Clearly Filtered 3-Stage | Waterdrop TSU | Frizzlife SK99-NEW & SP99-NEW | CuZn UC-200 | Aquasana Claryum 3-Stage Max Flow (AQ-5300+) |
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| Price (May 5, 2025) | $549 | $458.15 | $1,035 | $128 | $239.99 | $579.45 | $530.04 | $199.95 | $227.49 | 139.99 | $449.99 | $229.99 | $349.99 | $86.15 | $495 | $170.99 | $107.09 | $199.95 | $224.99 |
| Our Yearly Cost Estimate (May 5, 2025) | ~$200 | ~$145 | ~$175 | ~$175 | ~$360 | ~$185 | ~$160 | ~$100 | ~$252.50 | ~$140 | ~$205 | ~$320 | ~$165 | ~$140 | ~$440 | ~$172.50 | ~$90 | ~199.95 | ~$175 |
| Final Rating | 4.66/5.00 | 4.65/5.00 | 4.49/5.00 | 4.62/5.00 | 4.11/5.00 | 4.52/5.00 | 4.45/5.00 | 4.53/5.00 | 4.40/5.00 | 4.28/5.00 | 4.18/5.00 | 4.26/5.00 | 4.24/5.00 | 4.16/5.00 | 3.70/5.00 | 3.15/5.00 | 3.33/5.00 | 3.79/5.00 | 1.51/5.00 |
| Filtration Score (Lab Results, NSF Certifications + Other Test Data, Taste & Odor Test) | 4.50/5.00 | 4.50/5.00 | 4.50/5.00 | 4.50/5.00 | 5.00/5.00 | 4.50/5.00 | 4.50/5.00 | 4.42/5.00 | 4.40/5.00 | 4.44/5.00 | 5.00/5.00 | 4.89/5.00 | 4.14/5.00 | 4.46/5.00 | 4.14/5.00 | 2.16/5.00 | 2.30/5.00 | 3.07/5.00 | 0.00/5.00 |
| Usability Score | 5.00/5.00 | 5.00/5.00 | 5.00/5.00 | 4.75/5.00 | 3.50/5.00 | 4.50/5.00 | 4.00/5.00 | 4.50/5.00 | 4.50/5.00 | 4.75/5.00 | 4.50/5.00 | 4.50/5.00 | 4.00/5.00 | 3.00/5.00 | 4.75/5.00 | 5.00/5.00 | 4.75/5.00 | 4.75/5.00 | 3.50/5.00 |
| Cost Score | 4.82/5.00 | 4.73/5.00 | 3.95/5.00 | 4.87/5.00 | 3.32/5.00 | 4.58/5.00 | 4.75/5.00 | 4.90/5.00 | 4.28/5.00 | 4.61/5.00 | 3.91/5.00 | 3.38/5.00 | 4.79/5.00 | 4.43/5.00 | 1.34/5.00 | 4.28/5.00 | 5.00/5.00 | 4.99/5.00 | 4.04/5.00 |
| Lab Results Score | 4.84/5.00 | 4.87/5.00 | 4.96/5.00 | 4.50/5.00 | 5.00/5.00 | 5.00/5.00 | 5.00/5.00 | 4.92/5.00 | 4.65/5.00 | 4.44/5.00 | 5.00/5.00 | 4.64/5.00 | 4.39/5.00 | 4.46/5.00 | 4.14/5.00 | 3.16/5.00 | 3.30/5.00 | 3.57/5.00 | 0.00/5.00 |
Average Upfront Price
The average upfront price varies depending on the type of under sink filter we’re talking about. So, let’s break it down:
- For tank-based reverse osmosis systems, the average upfront price is $275. This estimate is based on those systems in our comparison, plus systems we found through general online research.
- For tankless reverse osmosis systems, the average upfront cost is higher at $450, with one outlier exceeding $1,000 (Waterdrop X12). Again, this estimate is based on the systems in our comparison, plus systems we found through online research. Note: Tankless RO systems are pricier than tank-based ROs since they use an electric pump to maintain the pressure needed for on-demand filtration.
- Regular, non-RO filters have the lowest average upfront price in our comparison at around $190.00, with outliers being as low as $86.15 (Culligan US-EZ-4) or as high as $495 (Clearly Filtered).
Average Long-Term Cost for Replacement Filters
Again, since we’re dealing with different types of under sink filters, we’ll break them down:
- In our comparison, the average annual cost for replacement filters for both tank-based and tankless RO systems is ~$200.00, which is slightly higher than for other water filter types. However, the price is skewed a bit by some models that cost ~$320 (GE GXRQ18NBN) and ~$360 (Aquasana SmartFlow) per year.
- For all regular under sink filters, the average long-term costs are roughly the same, around $200.00 in annual maintenance fees. Interestingly, the annual costs in this category vary even more widely from ~$90 (Frizzlife SK99-NEW) to ~$440 (Clearly Filtered) per year.
How Much Does a Good Under Sink Water Filter Cost?
So, how much does a good under sink water filter cost? Well, there are good systems in each under sink filter category.
Tank-Based RO Systems
Several tank-based RO systems performed really well in our under sink water filter comparison.
Our top choice is the Cloud RO, which also became our #1 under sink water filter overall. It costs $549 with our discount code ($599 without), which is nearly twice the average upfront price. However, our testing revealed excellent filtration results and usability, a high-quality design, an easy-to-use app for system monitoring, extremely low wastewater, and many more pros. Long-term costs are average at ~$200 per year.
Our tank-based RO runner-up and our #1 budget RO pick is the Aquasana SmartFlow, which costs a below-average $239.99 when you use our discount code. For that price, the Aquasana SmartFlow comes with NSF certifications for 88 contaminants, and our testing revealed almost perfect filtration results and decent usability, aside from some initial setup issues. Long-term costs are the highest in this category, though, at around $360 per year.
Other systems in this category that all achieved good to excellent filtration and usability include the US Water Systems All American 5-Stage RO, which is mostly manufactured in the USA and costs $579.45 upfront with our 5% discount code ($609.95 without), and with annual maintenance fees of ~$185. The Home Master TMHP-L HydroPerfection Loaded is also primarily made in the USA and offers the fastest faucet flow, and it costs $530.04 upfront, with annual maintenance fees of ~$160. Finally, the APEC-ROES-50 Essence comes in as the most budget-friendly RO, priced at just $199.95 upfront with annual maintenance fees of just ~$100.
Tankless RO Systems
Our top tankless RO pick is the Waterdrop G3P600 with an upfront cost of about $460 when using our discount code ($539 without), which is pretty average for this sub-category. For that price, you get a high-quality system with a handful of NSF certifications for contaminant reduction and excellent filtration results and usability in our testing. In the long term, the Waterdrop G3P600 offers affordable annual maintenance costs of just ~$145.
Our second tankless RO pick is the Waterdrop X12, which also achieved great filtration results and boasts both the fastest filtration speed and the lowest wastewater ratio (without automatic flushing). The primary reason for it getting second place? The high price tag of around $1,035 using our discount code ($1,299 without) makes it unaffordable for most people. Still, after the initial purchase, annual maintenance fees are below average at ~$175.
Regular Non-RO Under Sink Filters
In our regular under sink water filter category, the Epic Smart Shield including the optional faucet kit won hands down, offering solid filtration, great usability with a very fast faucet flow, NSF certifications for more than 60 contaminants, a lifetime warranty and satisfaction guarantee, and a budget-friendly price of just $128 upfront with our discount code. Long-term costs are also relatively affordable and below average at around $175 per year. Plus, there’s a filter recycling program (send in 3 cartridges, get 1 free).
Budget vs Expensive Under Sink Filters
It’s also helpful to compare the cheapest and the most expensive under sink filters tested to find out if paying a premium can make sense.
The cheapest system in our comparison is the Culligan US EZ-4, a regular under sink filter priced at just $86.15 upfront, with affordable annual maintenance fees of about $140. For that money, you get good filtration results (although not as good as an RO system), but mostly cheap plastic parts, including a dedicated faucet made of plastic, and average usability, with issues during the initial setup. Still, the Culligan US EZ-4 comes with NSF certifications for 66 contaminants, which sounds great for a budget model, although most are for easier-to-remove organics.
In RO filter systems, the most affordable is the APEC-ROES-50 Essence, a tank-based system which costs only $199.95 upfront and ~$100 in annual maintenance fees – both below average. For that price, you get nearly perfect filtration results in our testing, and usability is pretty solid, too. Aside from that, however, we really have just a standard tank-based under sink RO with all the pros and cons that that entails, such as considerable wastewater, issues with leaking, and only 1 NSF certification for contaminant reduction.
In comparison, the most expensive system is the Waterdrop X12, a tankless RO which, as mentioned, is around $1,035 upfront with our discount code, with more affordable long-term costs of about $175 per year (but you can save 5% with a filter subscription). For that price, you get nearly perfect filtration results, a system that looks and feels well-made, solid usability, a few NSF certifications for contaminant reduction (but interestingly, not as many as our cheapest system overall), and most importantly the fastest filtration and lowest wastewater ratio of all the RO systems we tested.
Another rather expensive system is the Clearly Filtered, a regular under sink water filter priced at $495 with our discount code ($550 without), with annual maintenance cost of ~$440. The upfront cost is exceptionally high for a non-RO system, and the annual fees is the highest of all the under sink filters we tested. What do you get for that price? Most importantly, the Clearly Filtered has only 2 NSF certifications for contaminant reduction, and in our testing, it achieved only satisfactory filtration and decent usability.
Bottom Line
In our opinion, when it comes to tankless and tank-based under sink reverse osmosis systems, you don’t have to pay a premium price to get a decent unit, but you don’t want to opt for the cheapest one either. For instance, the Cloud RO is a premium-priced system in the tank-based category, but it excels in performance and usability. The Waterdrop G3P600 is priced pretty average upfront for a tankless RO with affordable maintenance fees, and it also excels in filtration performance and usability. On the other hand, the cheapest RO system we examined, the APEC ROES-50 Essence, had issues with leaking, only 1 NSF certification for contaminant reduction, and considerable wastewater, which should be factored in when comparing costs.
For non-RO systems, the Epic Smart Shield performed very well in our testing and came in at a very affordable price (but not the cheapest), making it a good option for those who cannot afford an RO system. On the other hand, the Clearly Filtered regular under sink filter costs a premium price, but doesn’t perform as well as RO systems that cost less. In that case, if you are willing to spend that kind of money, you’d be better off investing elsewhere.
Under Sink Water Filter Cost Factors
Finally, this is a general list of factors that tend to affect under sink water filter costs, as well as how our models followed, or didn’t follow, those patterns.
The Filtration Process
The different filter media and methods used are often the same within the same filter category, but with some filters you get larger media volumes which may increase costs.
Additionally, some systems feature extra filter stages or additional treatments such as remineralization or UV disinfection. Examples for this are the Cloud RO (remineralization) and the Waterdrop X12 (UV).
Also, RO systems with electronic pumps tend to cost more than those without. This is a primary difference between tankless RO systems, which tend to cost twice as much on average as tank-based RO systems, because tankless requires an electronic pump to achieve decent on-demand filtration speed (as such, electronic pumps can actually hardly be seen as an additional feature in tankless ROs since they are mandatory for them to function). Tank-based ROs, on the other hand, usually don’t use electronic pumps, one exception being the Cloud RO which is one reason why it’s more expensive.
Aside from electronic pumps, there are also permeate pumps which some tank-based ROs use to significantly lower their wastewater.
NSF Certifications
Generally speaking, the higher the number of NSF certifications, the more expensive the water filter. This is because NSF certifications cost money, and they demonstrate due diligence since the manufacturer has taken the extra time to ensure the use of high-quality materials and effective filtration.
However, in the case of under sink filters, we did notice that the best-performing and more expensive systems didn’t have as many certifications as some of the cheaper ones did, and some of the most expensive even had few to none. This highlights that NSF certifications are just one of several factors to consider when deciding whether a system is worth it.
Replacement Filter Type
Modular replacement filter cartridges are usually more expensive than when cartridges and housings are separate, a pattern that generally held true in our under sink filter comparison, although not all followed the trend.
Proprietary filters are also often more expensive than standard-sized ones.
Filter Life
Longer-lasting filters mean fewer replacements, so lower long-term costs compared to similarly priced filters that don’t last as long. This trend holds fairly well in the under sink water filter category; generally speaking, the longer the filter life, the lower the annual replacement costs.
Overall Usability, Design & Quality
Looks, style, thoughtful and easy install/maintenance, and general ease of use may also affect costs. Also, water filters tend to cost more when they’re larger.
Additionally, as with most products, the higher the quality, the more expensive the system tends to be. This trend also held true for under sink filters across all three categories, with the cheapest systems tending to be made with lower-quality parts, and the most expensive ones generally appearing to be well-made.
Additional Features
Additional features can increase cost, such as filter life indicators, TDS monitors, or dedicated faucets.
When a water filter comes with a filter life indicator and/or TDS monitor, or even with an app that allows you to oversee your entire system from your phone, it also tends to cost more (or even far more like the Cloud RO). Remote monitoring in particular requires the use of electronic sensors and app development and maintenance, which naturally incur higher costs.
Finally, when a filter comes with a dedicated faucet, it also tends to cost more. Some dedicated faucets are made of plastic, while others are made of more durable metal, which also affects the cost.
Made in USA
Some water filters are made in the USA, or their filter cartridges are. We found that both usually add to the cost in our under sink water filter comparison.
Product Warranties & Satisfaction Guarantees
Most water filtration systems come with a standard one-year warranty. However, some products are covered for 2 years or even offer lifetime warranties, while others are only covered for 30 or 90 days.
In the under sink filter category, our more expensive systems typically have 2 to 5-year warranties, while the cheaper systems have only 1-year warranties. However, the Epic Smart Shield is very affordable and comes with a lifetime warranty, as well as a rare satisfaction guarantee.
Brand Perception
It’s common knowledge that Brands perceived as “premium” sell their products for more. Performance of premium brands is often better than average, but not always. Sometimes, you’re really just paying for the name.
Further Reading
About the Author(s)
Raoul has a background in mechanical engineering and has been writing about home water treatment since 2015. He designs our product review processes, analyzes the results, and ties everything together. As editor-in-chief, he tries hard to keep the whole operation running smoothly behind the scenes.