Are you thinking of buying an inline water filter? Not only do they save space, but they are highly efficient in removing over 99% of harmful particles.

In this article, we’re going to review the nine best inline water filters on the market. We’re going to highlight both the pros and cons of all nine models to help you decide whether they’re capable of meeting your requirements or not.

Then, we’re going to present a detailed inline water filter buying guide. In this section, we’ve answered the questions most people have about inline water filters.

So let’s dive right in.

In a Rush? Here are our Top Picks

9 Best Inline Water Filters

We rated all these inline water filters on the following criteria:

1. Six-month filter life (rated): Inline water filters with a six month rated life don’t require frequent replacement. This brings down their running costs, as you won’t have to purchase another filter anytime soon.

• Certifications: How do you verify whether a filter is capable of doing what it claims? By checking its certifications. That’s why the majority of inline water filters that we selected are ANSI/NSF certified.

• Lightweight construction: Some inline water filters will attach directly onto the main water line. Others will go behind your refrigerator. Still others would be installed on the back of the ice maker. To ensure easy installation, all of them must be lightweight.

Watts Inline Water Filter

• Weight: 2.04 pounds
• Filtration capacity: 20,000 gallons
• Filter life: 5 years
• Certification: NSF/ANSI 42 and 372

What is it that makes the Watts inline water filter the best on the market?

Start with its ultra-high filtration capacity. This inline water filter is capable of filtering up to 20,000 gallons of water in its lifetime, which means it requires replacement only twice every year. Most other filters that you see on the market stop working after processing 5,000 to 10,000 gallons.

Then comes its NSF 42 and 372 certifications.

Both certifications confirm that this filter is safe to use for point-of-entry as well as point-of-use systems. The certifications also assure you that this model can remove or reduce total dissolved solids (TDS), cysts, magnesium and other salts from water.

Its ¼’’ brass connector makes it easy to install because the majority of water lines used in homes these days are of the same size. Just make sure that you flush this filter with a bucket full of water to remove any material build-up before attaching its connector to the pipe.

Unfortunately, there’s one area this filter could have done a little better. Its package doesn’t include the tubing needed for installation, leaving you with no choice but to buy it separately.

What We Like:

• 20,000 gallons filtration capacity
• NSF 372 and 42 certified
• Removes chlorine, bad taste and odor

What We Don’t Like:

• No tubing for installation

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: ANSI/NSF 372 and 42
3. Lightweight construction: Yes

GE Inline Water Filter

• Weight: 0.9 pounds
• Filtration capacity: 150 gallons
• Filter life: Six months
• Certification: NSF/ANSI 42, 53, 401

How does the GP inline water filter compare with our top pick?

You might be surprised to note that it meets more standards than the Watts Inline Water Filter. While our top pick meets NSF/ANSI 42 and 372 standards, this unit is certified by IAMPO for standards 42, 53 and 401. That means it can remove more pollutants from your water supply.

Then why didn’t we select it as our top pick?

Mainly because its filtration capacity (150 gallons) is 10x less than that of the Watts Inline Water Filter (20,000 gallons). That means that if you use both these models to filter the same amount of water every day, the one from GE would require replacement first.

Luckily, that’s its only ‘shortcoming’.

This filter is capable of removing chlorine, cysts, bacteria, viruses and any other pollutants down to 0.5 microns. It can also filter out asbestos, lead and VOCs from water. And the fact that it requires only one cartridge means its running cost isn’t too high.

What We Like: 

• NSF 42, 53 and 401 certification
• Filters down to 0.5 microns
• Reduces lead, asbestos and cysts from water

What We Don’t Like:

• Low filtration capacity

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: ANSI/NSF 42, 53 and 401
3. Lightweight construction: Yes

EcoPure Inline Water Filter

• Weight: 1 pound
• Filtration capacity: N/A
• Filter life: 5 years
• Certification: NSF

Three features separate the EcoPure inline water filter from the Inline Watts Water Filter.

While the Inline Water Filter needs replacement every six months, the EcoPure keeps going for five years. Just make sure you maintain it regularly and it won’t be requiring replacement anytime soon.

Though it removes far fewer pollutants from water than its competitor.

The Watts Inline Water Filter can remove or reduce chlorine, taste & odor, sediments, cysts and magnesium from water. This model, however, isn’t able to effectively deal with microbial cysts as well as magnesium.

We have already noted that the Watts Inline Water Filter boasts ANSI/NFS 42 and 372 standards. That isn’t the case with this model.

What We Like: 

• 5-year filtration capacity
• Works with most brands
• Lightweight construction

What We Don’t Like: 

• Doesn’t include a compression nut, a brass insert and a plastic compression sleeve

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: NSF
3. Lightweight construction: Yes

Woder Inline Water Filter

• Weight: 1.35 pounds
• Filtration capacity: 10,000 gallons
• Filter life: Six months
• Certification: NSF/ANSI, WQA

What is it that sets the Woder inline water filter apart from the competition?

Start with its certifications. The Woder WD-10K is one of the very few water filters that are WQA Gold Seal certified. This means you can trust it to remove lead, heavy metals, chromium, mercury and even carcinogens from water.

We were also impressed with its ease of installation.

Its manufacturer has included a video in its package to make the whole process of connecting this model to your home’s water supply effortless. Also, since it connects to ¼’’ piping, you won’t have to buy another hose to connect it to your main water line

Its advanced filtration technology is impressive too.

That’s because it is capable of removing up to 99.9% of pollutants in the water, but not at the cost of essential minerals that your body needs for healthy functioning. That is the reason why the water it filters remains healthy for drinking purposes.

Having said that, this model doesn’t come cheap. Especially when you compare it with other top picks in this review.

What We Like:

• WQA Gold Seal Certification
• 10,000 gallons filtration capacity
• Has advanced filtration technology

What We Don’t Like:

• Cost

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: ANSI/NSF
3. Lightweight construction: Yes

LASCO Inline Water Filter

• Weight: 0.5 pounds
• Filtration capacity: 1,500 gallons
• Filter life: Six months
• Certification: None

The LASCO inline water filter offers 1,500 gallons of capacity. It is enough to keep this unit going for up to 6 months, even if your daily consumption of filtered water is 20 cups.

Most other ice maker inline filters only remove turbidity. The Lasco 37-1821 goes one step ahead.

It effectively removes sediments, chlorine and taste too. And it also meets the guidelines of the U.S. Environmental Protection Agency by reducing the quantity of harmful trihalomethanes in filtered water.

What’s more, filter can be installed both horizontally and vertically. The ¼’’ compression fittings needed to connect it to your refrigerator are also included in its package. That means you won’t have to spend a penny to buy additional equipment for installation.

That doesn’t mean that everything about it is great. The fact that it isn’t certified by ANSI/NSF means you can’t expect it to live up to the same standards as the top three models above.

What We Like:

• 6-months life capacity
• Removes harmful trihalomethanes
• Filters odor and taste in water

What We Don’t Like:

• Not certified by NSF/ANSI

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: No
3. Lightweight construction: Yes

Camco Inline Water Filter

• Weight: 0.5 pounds
• Filtration capacity: 1,500 gallons
• Filter life: Six months
• Certification: None

The Camco inline water filter relies on two filters to purify water. 

The first screen, which filters water before it enters the unit, removes particles greater than 20 microns in size. This means that all the particles which can potentially cause corrosion or rust inside the unit won’t be allowed to enter.

The second filter, made of granular activated carbon, is located in the middle of this unit. It is responsible for reducing odor, taste, chlorine and any sediments that were too small to be captured at the entry.

Both these filters help the Camco 40045 supply water for drinking, gardening and cleaning purposes

Most water filters are hotbeds of bacteria growth when not in use. However, the premium KDF construction of this unit protects it against the onslaught of bacteria when it’s sitting idle. It also has a flexible hose protector to prevent hose crimping, a common problem with inline water filters.

Though you cannot use it for ponds or fish tanks. That is because it doesn’t have any certification to confirm that its filtration capacity is high enough to provide safe water for either of the two applications.

What We Like:

• 20-micron sediment filer
• Granular activated carbon filter
• NSF/ANSI 362 low lead certification

What We Don’t Like:

• Not good for ponds or fish tanks

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: No
3. Lightweight construction: Yes

Culligan Inline Water Filter

• Weight: 3 pounds
• Filtration capacity: 500 gallons
• Filter life: Six months
• Certification: NSF, ANSI

How many inline water filters on the market are capable of offering a 0.5GPM flow rate? Which of them can handle water coming in at 60 psi? How many are warrantied for two years?

The Culligan inline water filter is one of very few that offer all three features.

This ANSI/NSF certified filter is also capable of removing particulates that could scratch its interior. It also reduces the quantity of chlorine, VOCs, cysts and other bacteria that are harmful to your health. You can even trust it to remove lead and bad odor/taste from your water.

Installing this inline water filter is simple. Mainly because its quick-connect fittings easily connect with compatible ¼’’ copper pipes. But also because its twist on/twist off mechanism allows you to swap the previous model with the new one within minutes.

A downside of this filter is that it doesn’t offer a horizontal installation option. So it might not be suitable for your refrigeration system if there is not enough space.

What We Like:

• 2-year limited warranty
• Quick connect fittings
• Twist on/off installation

What We Don’t Like:

• No horizontal installation option

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: NSF/ANSI
3. Lightweight construction: Yes

Amazon Basics Inline Water Filter

• Weight: 2.1 pounds
• Filtration capacity: 1,350 gallons
• Filter life: Six months
• Certification: None

This ‘high capacity’ Amazon Basics inline water filter is an excellent choice for people who need filtered water for drinking purposes only. That’s because its 1,350 gallons capacity, which looks huge on paper, is relatively modest. It is the 3^rd lowest of all the models we have reviewed thus far.

There is one feature of this model that is a huge plus. When compared with the Camco water filter, which costs twice as much, this model’s flow rate and water handling capacity are bigger.

Don’t count on this filter to remove VOCs, lead, bacteria or viruses though. As both its pre-sediment filter and KDF technology can only take care of big sediments.

What We Like:

• Competitive asking price
• Connects to a standard water hose
• 1,350 gallons service life

What We Don’t Like:

• Not reliable to remove VOCs, lead, bacteria and viruses.

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: No
3. Lightweight construction: Yes

3M Aqua-Pure Inline Water Filter

• Weight: 0.9 pounds
• Filtration capacity: 2,000 gallons
• Filter life: Six months
• Certification: NSF

The majority of inline water filters can remove particles down to 20 microns. Only a select few are capable of drilling down to 10 microns.

The 3M Aqua-Pure inline water filter belongs to the minority that can separate particles as tiny as 5 microns in size, which include bacteria, viruses and paint pigments.

Its two filters – both of which are certified by NSF – are the reasons why this model can filter down such small size particles. The activated carbon is responsible for blocking the entry of sediments, scales and rust particles at the filter’s gate.

The inner porosity media, meanwhile, catches viruses, bacteria, taste & odor, and chlorine particles inside the filter. It is due to the combined efforts of both these filters that the water coming out of the Aqua Pure is safe for drink dispensers, coffee machines and drinking fountains.

As for downsides, for this particular filter, we think that metal would have been a better choice for guaranteed longevity. In addition, the amount of water it takes for initial flushing is too wasteful for our liking. 

What We Like:

• Filters down to 5 microns
• NSF 42 certified
• One-year limited warranty

What We Don’t Like:

• Plastic construction

How It Compares With Our Criteria

1. Six-month filter life (rated): Yes
2. Certifications: NSF
3. Lightweight construction: Yes

What is an Inline Water Filter?

An inline water filter removes impurities by becoming a part of your water supply line. This allows it to deliver crystal clear water without requiring any external devices or attachments. An inline water filter is one of the most popular, reliable and inexpensive options for purifying water.  

You can also attach it to the pipe supplying water to your sink. The ceramic candle inside the filter’s housing will purify the water before it comes out of the tap.

How Do Inline Water Filters Work?

Inline water filters work by subjecting water to physical and chemical filtration.

The first stage of filtration is physical, in which water is passed through a fine textile membrane or a thin gauze. This stage removes larger impurities such as dirt, dust and sediments.

The second stage, which is only found in pricey inline water filters, involves passing water through a bed of activated carbon or activated charcoal. Both these materials let water pass through while absorbing its impurities (chemicals, bacteria, fluoride, chlorine, etc.) on their surface.

Benefits of Inline Water Filters

Here are the biggest benefits of inline water filters:

Inline water filters run 24/7

Inline water filters never go to sleep. Unlike your standard under-sink water filter, which filters only a portion of cold water running through your water line, a whole-home inline water filter will purify all the water flowing through your house’s cold water line.

Inline water filters are compact

Inline water filters save you from the trouble of freeing up space on your kitchen counter or in your kitchen cabinet. And they don’t require purchasing additional hardware that some water filters require to function.

Inline water filters are long-lasting

Inline water filters are the epitome of durability. Most of them last for as much as six months before needing replacement.

Some, like the watts inline water filter, last for 18 months. We suggest that you get a filter with a long service life to save money on its replacement.

Inline water filters are highly efficient

Expensive inline water filters have multiple layers of filtration.

The first layer is primarily responsible for removing sediments, dust particles and dirt. The next layer removes taste and odor, and the remaining layers, especially in pricey models, filter out chemicals, bacteria, chlorine and heavy metals.

Inline water filters are incredibly versatile

Inline water filters can be used for various applications. You can either get one that would filter the entire home’s cold water supply. Or you can get a dedicated inline water filter for your refrigerator, icemaker, fridge, water cooler, motor home, or boat.

Inline water filters are cost-effective

Inline water filters have lower upfront and installation costs because they work with a pre-existing kitchen tap. They have lower running costs because their cartridges don’t cost much to replace, thereby bringing down their annual maintenance cost.

Disadvantages of Inline Water Filters

Here are the drawbacks of inline water filters:

Inline water filters aren’t easy to install

Compared with countertop water filters, which only require you to attach them to the tap, inline water filters aren’t easy to install.

You need some basic plumbing skills to unscrew the braided flex hose, clean the male connection thread and implement the remaining steps.

Inline water filters can’t be reused

So your inline water filter has reached the end of its service life? Prepare to invest in a new inline water filter.

Here’s why: inline water filters cannot be reused and need to be replaced in full. This sets them apart from other water filters that keep going with a filter cartridge replacement.

Inline water filters offer a single point of use

Since these water filters install directly onto the cold water line, the water they’d filter will come out of a single appliance or tap. That means that if you need filtered water at multiple locations or fixtures, you’d need to buy multiple inline water filters.

How to Choose the Best Inline Water Filter

Here are several things you need to pay attention to when you’re in the market for a new inline water filter:

Type of Inline Water Filter

Deciding which of the types you need depends on the purpose for which you’re going to use filtered water.

Here’s what we mean:

Will you use an inline water filter for refrigerator or ice maker? Or are you going to use filtered water for washing dishes or drinking water?

Another question you have to answer is the location where you’d install it. An inline water filter made for home use is different from another made for an RV or camper.

Here are types of inline water filters:

• Refrigerator Inline Water Filter: Do you need filtered water for an ice maker or refrigerator? Then you may need an inline water filter. Especially if you have an ice maker, as they don’t have a built-in filter and are susceptible to producing smelly, hazy ice.

• Under Sink Inline Water Filter: Under-sink filters process large amounts of water and won’t gobble up countertop space. On the flip side, they are often pricey and require extensive modifications to existing plumbing for their installation.

• RV/Camper Inline Water Filter: To select the best inline water filter for your RV, pay attention to what’s in the water you want to filter. Also, decide the quantity of water you’d be sifting and how frequently you’d be using the filter.

Your Water Supply

What is in your water supply? The answer to this question will determine whether you need an inexpensive water filter (that can remove the commonly-found sediments). Or would you be better served with an expensive, multi-stage water filter.

Here’s an easy way to determine what exactly is in your water supply: your location.

Rural Areas

According to the US Centre for Disease Control and Prevention, residents of rural areas need to filter their water for harmful bacteria, chemicals, and dust particles.

That’s because the water sources in rural areas (well, lake, or spring) are mostly inundated with these pollutants.

Here’s what the advice means: invest in an inline water filter rated to handle all the pollutants mentioned above. Don’t splurge your hard-earned money on a unit that is rated for sulfur or chlorine.

Both these contaminants aren’t commonly found in rural areas’ water supply.

Urban Areas

Urban areas’ water supply might be rich in heavy metals, bacteria, nitrates, chlorine and sulfur. That’s because groundwater in urban areas receives contaminants from many sources. They include garbage dumps, chemical storage tanks, toxic water and dumping of hazardous substances.

How to treat this water?

By investing in an inline water filter rated for chlorine, sulfur, bacteria and heavy metals. Any filter that is rated for all four pollutants won’t come cheap. But it might save you from waterborne diseases such as hepatitis, diarrhea, and stomach cramps.

Micron Rating

The average size of openings in the filter media or between pieces of filter media is its micron rating. The greater the size of the opening, the larger particles the filter will allow through. For example, a 0.5-micron filter will do a better job of blocking sediments than its 20-micron counterpart.

Here are answers to the questions you may have about micron rating:

• Which is better 1 micron or 5 micron? Since they are able to block much smaller particles – and therefore ensure greater water purity, 1 micron filters are invariably better than their 5 micron counterparts.

• What does a 0.2 micron water filter remove? You can count on a 0.2 micron water filter cartridge to remove (or reduce) bacteria, viruses, sediments, ultra-fine particles, cysts, parasites and other contaminants.

• How many microns does it take to remove chlorine? To remove chlorine from tap water, you need a 0.2 micron filter. It will also remove (or reduce) heavy metals, lead, sediments and organic chemicals from your water supply.

• How many microns should your inline water filter be? Make sure your inline water filter is 1 micron, especially if you live in an urban area. Cities’ water supply might contain cysts or other bacteria that only a 0.1-micron filter can remove or reduce.

• What’s the difference between absolute and nominal micron rating? Absolute micron rating means that 99.9% of the particles larger than the rating won’t pass. Nominal micron rating implies a majority of the approximate size particles won’t pass through the filter.

Certifications

GE Replacement Water Filter, one of our top picks, has the following certifications. While it isn’t necessary for your inline filter to have all of these, models with these certifications will do a better job of filtering water than those that don’t.

• NSF 42

The NSF 42 certification covers both point-of-entry and point-of-use systems. That means it applies to whole house water filter systems as well as single-point or point-of-use models.

NSF 42 certified filters remove or reduce the quantity of total dissolved solids (TDS), cysts, iron and magnesium from treated water.

But remember, they don’t protect against VOCs, chromium and lead.

• NSF 53

Like the NSF 42 certification, the NSF 53 standard also covers both point-of-use and point-of-entry water filters. That’s where the similarities end. NSF 53 certified water filters do a better job of filtering water.

Filters that are NSF 53 certified are capable of removing or reducing everything that may contaminate your water supply, including chromium, volatile organic compounds (VOCs) and even lead.

• NSF 401

NSF 401 certified water filters are capable of removing up to 15 contaminants from water. For the sake of comparison, their NSF 53 certified counterparts can remove or reduce more than 50 toxicants.

Most of the contaminants NSF 401 certified filters remove are those found in the rural water supply. Examples include herbicides and pesticides. Though some, such as medicine traces, also contaminate urban water lines.

Filtration Capacity

Filtration capacity determines how many gallons of water a filter can purify in its lifetime.

Inexpensive models, like this one from Amazon Basics, have a meager filtration capacity. Models that cost more, like the Watts Inline Water Filter, can purify as much as 20,000 gallons before needing replacement.

Having said that, stay away from relating filtration capacity and the filter’s service life. Any model that can filter 50,000 gallons won’t last 45 years, even if you and your family members consume only 3 gallons of filtered water every day.

Here’s why: the filter’s service life depends on the quality of water in your area, the contaminants it has to deal with, and the flow rate it must handle on a daily basis. All these and other factors might combine to increase or decrease your inline filter’s service life.

Inline Water Filters Vs Reverse Osmosis

Here are the differences between inline water filters and reverse osmosis:

How does water filtration work?

Water filtration removes or reduces contaminants from water by passing it through a block of activated carbon or charcoal. Inline water filters with multiple stages may also remove taste, odor, micro-organisms, and volatile organic compounds.

However, not all water filters are the same.

Depending on the quality of their filter media, the stages of filtration and the material of construction of the filtration media, some water filtration systems will work better than others. Click here to know more.

What contaminants do inline water filters remove?

Inline water filters effectively remove the following contaminants:

• Chlorine
• Sediment
• Dirt
• Rust
• Taste and odor
• Heavy metals
• Arsenic
• Volatile Organic Compounds (VOCs)

What are the micron rating and filtration capacity of an average inline water filter?

Standard whole-house inline water filters have a filtration capacity between 10 to 30 microns. They are also able to process up to 10 gallons of water per minute. This is what makes them an ideal choice for bathroom, shower, gardening and cleaning purposes.

How does reverse osmosis works?

RO systems filter water by sending it from a low-pressure to high-pressure area via a high-pressure pump. Both these areas are separated by a semi-permeable membrane, which makes sure that up to 99% of pollutants are left behind as water leaves the low-pressure area.

The effectiveness of reverse osmosis could be gauged from the fact that it removes particles of up to 0.0001-micron size. By contrast, the micron rating of most inline water filters ranges between 10 to 30 gallons. That’s why reverse osmosis systems are a better choice to get pure drinking water.

What contaminants do reverse osmosis remove?

Reverse osmosis systems effectively remove the following chemicals:

• Salts and nitrates
• Heavy metals like lead and copper
• Organic chemicals (fluoride)
• Viruses such as Rotavirus, Norovirus and Hepatitis A
• Bacteria like E. coli, Shigella and Salmonella
• Chlorine, turbidity, TDS

What are the micron rating and filtration capacity of an average RO system?

Standard reverse osmosis systems have a micron size of 0.0001. To understand how tiny that size is, consider that bacteria is 0.4 to 1 micron; virus 0.02 to 0.4 micron and human hair is 80 to 90 micron. Little wonder, then, that RO systems can effectively remove up to 99.9% of waterborne pollutants.

However, while their micron rating is excellent, the filtration capacity of RO systems (up to 45 gallons per day) restricts their utility to drinking and cooking.

Conclusion

Picking the best inline water filter isn’t easy. And the filter you choose will depend on what your individual needs are.

But in general, we recommend going for one with at least a 6 month rated life that has ANSI/NSF certifications.