If you live in an apartment, you probably often think about maximizing space. If you’re also in the market for a water filter, you might feel like you’ll have to compromise on quality to get a unit that fits. Our research and testing confirm that’s not the case. From countertop systems to filters that attach directly to your faucet, there are plenty of high-quality options out there that are not bulky.
We created this list of the best water filters for apartments to give you all the information you need to pick the right one for your specific needs.
Here’s the TL;DR: The best overall apartment water filter we tested was the RKIN U-1, an incredibly versatile unit that provides instant hot water and has hydrogen infusion capabilities.
Our favorite countertop model was the AquaTru Reverse Osmosis Water System as it can remove 84 different contaminants and requires no installation—you just plug it in an electricity outlet and that’s it.
But if you don’t have the budget for either of these units, we recommend the PUR PLUS Faucet Mount Water Filtration System, which costs just $31.05.
- Contaminants Removed – 99% including heavy metals, chlorine, and fluoride
- Warranty – 1-year
- Contaminants Removed – 84 contaminants
- Warranty – 1-year
- Contaminants Removed – 365+ contaminants
- Warranty – Limited lifetime warranty
- Contaminants Removed – 70
- Warranty – Information unavailable
- Contaminants Removed – 232+
- Warranty – Limited lifetime warranty
- Contaminants Removed – 232+
- Warranty – Limited lifetime warranty
Apartment Water Filters
RKIN U-1 – Best RO System
- Contaminants Removed – 99% including heavy metals, chlorine, and fluoride
- Warranty – 1-year
- Price – $749.95
PROS
- Its highly effective filtration system means it can remove up to 99% of contaminants
- You can use it for cold filtered water and instant hot water. We really liked using it to make tea and coffee
- The intelligent touch control panel makes it easy to control the settings and keep track of the condition of the filter
- It has an optional hydrogen infusion stage that creates enriched water with antioxidant properties. We haven’t come across many systems that have this feature so we were pretty impressed
- It includes a UV light that keeps the water in the storage tank fresh when you’re not using the system
CONS
- It only comes with a 1-year warranty so you’ll have to pay out for repairs and replacements outside of this time period
- It’s the most expensive unit on our list
The RKIN U-1 is one of the most versatile water filters we’ve ever tested. It gives you instant hot water, can produce hydrogen-enriched water, and even has a UV light to keep your stored water fresh. Plus, it’s highly effective at filtering out contaminants—it has a 99% success rate.
We chose it as the best overall water filter for an apartment as it’s sleek and compact without compromising quality. The fact that it’s the most expensive unit on our list means it’s best suited to those with a relatively large budget who want a top-of-the-range system.
4-Stage Filtration
The U-1 features advanced 4-stage filtration that enables it to remove up to 99% of contaminants. We used it to filter well water and we were pleased with the clean, clear water it provided. There are plenty of countertop units that can’t handle well water so this was a nice surprise. Here’s how its filter system works:
- Sediment filter: The first stage removes sediment, sand, and rust.
- Activated carbon filter: This removes carcinogens and chemical residues like THMs, VOCs, and pesticides, as well as bad tastes and odors in the water.
- Reverse osmosis (RO) membrane: The third stage removes any remaining contaminants.
- Alkaline post-filter: This reintroduces the beneficial minerals removed during the RO stage such as calcium and magnesium.
We love that RKIN has included a remineralization stage. Many RO systems don’t include this, which means the water they produce can be low in beneficial minerals like calcium and magnesium, which are important for dental and bone health.
Intelligent Touch Control Panel
When we test water filter systems, we also look for user-friendly digital interfaces. These interfaces simplify the maintenance process and give you complete control over your device. You can imagine how happy we were to discover that the U-1 has one of the best interfaces we’ve ever encountered.
It has a range of buttons that allow you to control the water temperature and the volumes of water you want it to dispense. For instance, if you want a small cup of coffee, you can get it to dispense 5 fluid ounces of boiling water instantly.
The display also gives you updates on the condition of the filter. The Filter Life light turns yellow when the filter has reached 80% capacity and red when it needs to be replaced. This excellent digital interface is one of the reasons the U-1 tops our list.
Optional Hydrogen Infusion
There's an optional hydrogen infusion stage at the end of the 4-stage filtration process. If you turn it on, you get hydrogen-enriched water with a negative ORP of 340, which has several potential health benefits.
As the U-1 uses RO, this is a really nice touch. Not only does it include a remineralization stage, but this optional hydrogen infusion stage means it produces some of the healthiest water of any RO system we’ve tested!
AquaTru Reverse Osmosis Water System – Best RO System
- Contaminants Removed – 84 contaminants
- Warranty – 1-year
- Price – $381.65
PROS
- A very effective device that removes almost all common contaminants from the water
- Easy to maintain and replace filters
- Long-lasting (capacity: 1,400 gallons for the first three filters; 800 gallons for the final filter)
CONS
- Like the U-1, it only has a 1-year warranty which is really short compared to the lifetime warranties of some of the other units on our list
The AquaTru is a great water filtration system for any household, and especially for apartments. It’s compact, requires no setup or installation, and is remarkably powerful for its size. Although its features aren’t quite as impressive as the U-1, it’s almost half the price. So, it’s a good option if you want a high-end system but you’re on a fairly tight budget.
Effective Filtration
Like the U-1, it uses a four-phase filtration process to ensure that all contaminants in the water are removed.
- The first phase is the mechanical pre-filter. This phase removes large sediment particles and cloudiness from the water.
- The second phase is the activated carbon pre-filter, which eliminates chlorine (99%) and chloramine traces.
- The third phase is the reverse osmosis filter that catches and removes inorganic pollutants.
- The fourth and final step is the activated coconut shell carbon filter that stops organic contaminants.
All these filtration phases and the thorough water purification process make this a powerful unit. With such power, we expected the process to take quite a while but that’s not the case: it only takes 15-20 seconds.
No Installation and Little Maintenance
This countertop RO model is effortless to use since you only need to plug it into a power socket and fill the reservoir with water. After that, press the start button, and the device will take care of the rest.
The maintenance procedure is very simple. The media comes in cartridges inserted in separate slots inside the filter. You rotate the cartridge one way to secure them in the slot and the other way to dislodge them from the slot when it’s time to replace them. As for the reservoir, use a few drops of dish soap and a sponge to clean the inside walls gently every week.
Long-Lasting Filters
The RO system and the two pre-filters are capable of purifying around 1,400 gallons of water, while the activated coconut shell is able to process about 800 gallons. As apartments tend to have much lower water demands than larger homes, the filters should last for quite a while before they need to be replaced. This is great as it saves you money in the long-term.
Clearly Filtered Water Pitcher – Best Water Pitcher
- Contaminants Removed – 365+ contaminants
- Warranty – Limited lifetime warranty
- Price – $81
PROS
- Very easy to use and takes up very little space, making it ideal for apartments
- The filter lasts for around 6 months so you won’t have to pay for replacements too regularly
- Comes with a 30-day money-back guarantee, which gives you plenty of time to test it out and see if it’s right for you
CONS
- The filter replacements are fairly expensive but the unit itself is so cheap that this isn’t a huge issue
Pitchers are popular thanks to their ease of use, and the Clearly Filtered water pitcher is no exception. This pitcher is the definition of simplicity. It has very few components and no moving parts. The unit has a lid at the top that covers the reservoir where you pour in the water. The water then seeps through the reservoir into the semi-spherical filter just underneath.
If you’re looking for a device that’s highly effective at filtering out contaminants despite its size and that fits in any refrigerator, this is the right unit for you.
Key Features:
- 3-stage filtration: This model has three filtration stages, all containing different filtration media. The woven mesh screen neutralizes large sediment particles, and the granulated coconut carbon reduces chlorine. The final stage is the composite shell that uses 7 proprietary filtration materials to reduce commonly found contaminants. Once the water passes the filter, it enters the large basin at the bottom. The water remains in the basin until you pour yourself a glass.
- Good storage and filter capacity: The basin stores around 80 ounces of water or approximately 10 glasses. As for the filters, they have a lifetime of about 100 gallons or 160 full containers. This should last around 6 months if you use the pitcher once per day or 3 to 4 months if you use it more frequently.
- High contaminant removal rates: The product reduces 99% of all fluoride, microplastics, PFAS/PFOA, and lead in your water, but its efficiency depends on the state of the water it’s treating. Water that’s too contaminated will either clog it or won’t be purified. If you notice discoloration or smell from the water even once it’s passed the filter, it’s a sign you need a more robust unit.
- Money-back guarantee: The pitcher comes with a 30-day money-back guarantee, so you can return it if it doesn’t meet your expectations.
PUR PLUS Faucet Mount Water Filtration System – Best Compact System
- Contaminants Removed – 70
- Warranty – Information unavailable
- Price – $31.05
PROS
- It’s a tankless system that attaches directly to your faucet which means it takes up no space at all on your countertop
- Its contaminant removal capabilities are NSF/ANSI certified to standards 401, 42, and 53. This means it’s been independently lab-tested
- It’s incredibly easy to install. All we had to do was screw it onto the end of the faucet.
- It’s by far the cheapest unit on our list at just $31.05
CONS
- The filter only lasts for around 3 months so the costs can start to mount up
The PUR PLUS is the best option if you’re on a very tight budget and you’re really short on space in your apartment. It’s a fairly basic unit that attaches to your faucet without the need for a tank. Clearly, it’s super compact, but it’s still a powerful filter that can remove 70 different contaminants including lead and microplastics.
Key Features:
- NSF certified: A third party in a lab has tested the unit’s ability to remove contaminants like lead and microplastics. As a result, it has NSF/ANSI 401, 42, and 53 certifications. We always look out for this when testing filters as it shows that the filtration process has been independently assessed.
- Indicator lights: The PUR PLUS includes an indicator light that tells you when the filters need to be changed. Although this is much more basic than the U-1’s digital interface, it’s still useful considering this unit's size.
- Easy installation: We didn’t need to use any tools to install the PUR PLUS and we certainly didn’t need to hire a plumber. All we had to do was unbox it and screw it onto the end of the faucet.
- Guarantee: Although the manufacturer doesn’t provide warranty information, the unit comes with a 30-day satisfaction guarantee. So, if you’re unhappy with the unit you can send it back within 30 days of receiving it.
Clearly Filtered 3-Stage Under the Sink Water Filter System
- Contaminants Removed – Lead, chlorine, asbestos, particulates, Benzene, and more
- Warranty – No
- Price – $30.89
PROS
- Long-lasting filters that don’t need to be replaced for up to a year
- Impressive contaminant removal rates mean it can remove up to 99.99% of more than 232 contaminants
- It can be installed under any sink and it doesn’t require a separate faucet to be installed alongside it
- Although it removes contaminants like lead, fluoride, chlorine, and PFAS, it doesn’t remove beneficial minerals like calcium
- Certified to NSF/ANSI standards 42, 53, 401, and 473
CONS
- The replacement filters are very expensive at $396
The Clearly Filtered 3-Stage Under The Sink Water Filter System can easily be installed under any sink to help you maximize the space in your apartment. It has very high contaminant removal rates and, and like the PUR PLUS, it’s NSF certified. At $550, it isn’t exactly cheap. However, we think you get plenty of bang for your buck.
Key Features:
- Advanced filtration: This unit features Clearly Filtered’s patented Affinity Filtration Technology. The tech includes a blend of 6 different filter media which are highly effective at removing contaminants like VOCs, pesticides, herbicides, and heavy metals. Unlike many other systems, especially those that use RO membranes, this unit’s filters don’t target beneficial minerals.
- Long-lasting filters: Unlike the PUR PLUS, the filters can last for up to a year. This is really helpful as, at $396, the replacement filters aren’t that far off from being as expensive as the entire unit.
- Universal compatibility: One of the issues we’ve had with other under-sink models is that they only work with certain types of sinks and you often have to install a separate faucet. This isn’t the case with this system. It’s compatible with any sink and you can carry on using your existing faucet.
Clearly Filtered Universal Inline Fridge Filter – Best Fridge Filter
- Contaminants Removed – 232+
- Warranty – Limited lifetime warranty
- Price – $165
PROS
- Unlike many other inline fridge filters, it’s compatible with all fridge makes and models
- Like the Clearly Filtered under-sink model, it can remove up to 99.99% of contaminants
- It’s super easy to install. We just had to connect it to the water line and then mount it next to the fridge
- Depending on the number of people that live in your apartment the filter can last for up to 15 months
- NSF certified for standards 42, 53, 401, and 473
CONS
- When the filter reaches its capacity, you need to replace the entire thing which means paying the full price of the unit again
The Clearly Filtered Universal Inline Fridge Filter is probably the best fridge filter we’ve tested. Despite its tiny size, its filter is as powerful as many larger under-sink models and can effectively remove over 232 contaminants. It can be mounted behind or next to your fridge so it takes up very little space. In fact, once it’s installed, you won’t even notice it’s there.
Key Features:
- Superb filtration: As with the Clearly Filtered under-sink model, it uses Affinity Filtration Technology which enables it to remove up to 99.99% of contaminants from water.
- Filter longevity: We were very impressed with how long the filter lasts. If you live alone, it should last around 15 months. If you live with one other person, it should still last about 12 months. This is very good news, as it’s very expensive to replace the filter once it reaches its capacity.
- Discreet design: The unit is designed to be as compact as possible and it can be installed so that it’s completely out of sight. You can either mount it on a wall next to your fridge or behind it so that it can’t be seen.
Types of Apartment Water Filters
This guide covered five types of apartment water treatment units, including a countertop reverse osmosis system, water pitcher, under-sink, faucet, and inline refrigerator filter.
We want to note that there are many other types of filtration units that may also be used in an apartment, and there are even many more subtypes and variations than the devices we picked that may work for your particular conditions.
We chose the most popular and convenient models.
Plus, we believe our picks are varied and versatile enough for anyone to be able to find their ideal match.
How Do the Different Apartment Water Filters Work?
These devices work in different ways.
Countertop Reverse Osmosis Filter
Countertop products like the AquaTru unit are portable and usually placed on a surface within the kitchen. These units must be plugged into a power socket to work.
Once the device is plugged in, you just push the start button, and the filtration process will start automatically. The water is passed through 4 different stages, each removing specific contaminants.
The filtration process is very thorough and removes most contaminants that may be found in your drinking water, like lead, chlorine, fluoride, PFAs, nitrates, and others. Surprisingly, it’s also very quick, as it only takes 10 – 15 seconds from start to finish.
Water Pitcher Filter
Water pitchers have their filtration reservoir at the top. The water is poured into the reservoir, and gravity takes it into the semi-spherical filter below it. There, the water is treated and goes into the basin, where it stays until you need a glass.
Faucet Filter
Faucet models are small devices that need to be attached to the end of the faucet. For instance, the Brita requires a single lithium battery for power, but other than that, its setup doesn’t need any connections or tools. You just need to flip a switch to turn it on.
The device works when the light is on, while the water flows through the unit without passing the actual filter when it’s switched off. Turning it on and off will extend its life, so remember to only turn it on when you need clean drinking water.
Under-Sink Filter
Under-sink water filters (as the name suggests) are installed underneath your sink and are attached to the water line. They don’t need to be connected to a drain and they don’t require a storage tank, which makes them an excellent choice for apartments. Plus, they also don’t need to be connected to electricity.
When you open the faucet, water passes through the filter, and contaminants are removed before it reaches the faucet.
Inline Water Filter
Unlike standalone filtration units, inline water treatment products are installed directly into your home’s plumbing, effectively treating water as it flows through the pipes. They may be used on a single sink or refrigerators with an ice maker or water dispenser. The latter is a good choice for older refrigerator models that don’t have built-in filters.
External inline water units need to be attached to the water hose at the back of the fridge. To do this, turn off the refrigerator and disconnect the water hose. Attach the hose to one end of the unit, and attach the other end of the device to the refrigerator port where the hose is supposed to connect.
We recommend using zip ties or a bit of string to suspend the unit on something so that it doesn’t pull on the hose as it hangs.
Advantages and Disadvantages of Each Filter
All the apartment filters on our list have their strengths and weaknesses. We have tried to summarize and explain the pros and cons of each model type to help you figure out what to expect from them.
Countertop Reverse Osmosis Filter
Advantages—Reverse osmosis systems are known for being very thorough, and the countertop models are no exception. They have very effective filters and other useful features like adjustable filtration modes, timers, and Bluetooth connectivity that give them an edge over other models.
Disadvantages—The effective filters and other helpful features come at a higher asking price. Many RO countertop systems are reasonably priced for their quality. Still, most are much more expensive than any other apartment filtration unit.
Water Pitcher
Advantages—These items are very compact and easy to maintain. To clean them, you just need a sponge and a bit of soap. The water pitchers themselves are also affordable.
Disadvantages – Pitchers don’t have strong filters. While they are typically effective at eliminating common water contaminants such as chlorine, lead, and certain heavy metals, water filtration systems have a limit to the amount they can remove before becoming clogged. So, they shouldn’t be the first choice for people living in an area with highly polluted water.
Faucet Filter
Advantages—Faucet models are effortless to install. They must be attached to the end of your faucet, and once turned on, they automatically treat the water that passes through them. They’re also one of the cheapest, if not the cheapest, water treatment units.
Disadvantages—Similar to pitchers, faucet devices remove lead, chlorine, and other contaminants from the water. Still, they easily get clogged if the water is highly polluted or the filter isn’t changed regularly. The placement of these devices also makes them easy to hit and break with dishes or even your hands.
Under-Sink Filter
Advantages—These filters are really easy to install, as they only need to be connected to your sink’s water line. Because they're directly connected to the water line, they have much faster flow rates than pitchers and other types of units. As they’re installed under the sink, they take up no space on your kitchen countertop, which is particularly beneficial for apartment living.
Disadvantages—The main downside of under-sink units is that they’re much more expensive than more basic models like pitchers and inline fridge filters. Additionally, although they’re easy to install, they often require a hole to be drilled into the kitchen countertop.
Inline Water Filter
Advantages—Inline refrigerator models are small and easy to install. They don’t take up any space or require maintenance. They’re also affordable, and it’s rare to find an inline product with a price in the triple digits. Additionally, they tend to last for around 6 months or more, with certain brands able to provide filtration for a year.
Disadvantages—The only disadvantage that inline water filters have is that they’re limited in terms of functionality. They only remove a limited number of contaminants and don’t have removable cartridges, so you need to replace and reattach the device once the old one runs out. External products are also more annoying than internal ones since they’re trickier to install.
Frequently Asked Questions
Here are what we found to be the most commonly asked questions on apartment water filters.
The cheapest apartment water treatment unit we found was the PUR PLUS at $31.05. Not only is it the most cost-effective product on our list, but it’s one of the most affordable methods to remove contaminants.
Countertop RO systems usually start at around $100 and can go up to $600.
Water pitchers are generally priced between $30 and $200.
You can find gravity units for as little as $100 or as much as $500.
Faucet filters are, without a doubt, the most affordable on our list, as you can get them for anything between $15 and $30.
External inline water filters range from $15 to $150.
None of the countertop models on our list require any installation. The RO unit and the U-1 need a power source to function, whereas the other units don’t even need that. Faucet devices need to be attached to the end of the faucet. This requires you to loosen the attachment point, put the item on the end of the faucet, and tighten it in place. Then, you just need to switch it on, start the water, and the filtration process will begin.
And finally, we come to the external inline model. First, turn off the refrigerator. After you’ve done that, turn the fridge so that you have easy access to the back. Once here, you’ll find the water line leading to the fridge. Once you’ve located it, you’ll need to detach it from the fridge.
Next, connect the water line to the in-line device and attach the device to the injection port on the fridge. It’s advisable to use a bit of string or zip ties to secure the purifier in the back of the refrigerator, but that’s entirely optional.
Once the product is in place, we’d suggest taking it for a test drive to ensure it works. Also, ensure that the filter is attached correctly and that nothing leaks while you’re using the ice maker or the dispenser.
Conclusion
The RKIN U-1 is the clear winner as it has the most comprehensive set of features while still being compact enough to suit an apartment's space requirements. We particularly liked its intelligent touch control panel, which enables full monitoring and control of the unit. Plus, we loved its versatility.
The runner-up, The AquaTru Reverse Osmosis Water System, is a powerful filtration system that’s an excellent option for anyone living in an area with very polluted water.
The Clearly Filtered Water Pitcher is simple to use and a great option for anyone who just wants a clean drink of water without using overly expensive and complicated filtration units.
If you’re looking for an even more compact system and you’re on a tight budget, then you can’t go wrong with the PUR PLUS.
The Clearly Filtered 3-Stage Under the Sink Water Filter System can remove over 232 contaminants and easily be installed under your sink without needing an extra faucet.
The Clearly Filtered Universal Inline Fridge Filter is compatible with any type of fridge and its filter can last up to 15 months, depending on your water usage levels.