Everything You Should Know About Under Sink Water Filter

Disclaimer: There are affiliate links in this post. At no cost to you, I get commissions for purchases made through links in this post.

If you’re like most homeowners, you probably take your water for granted. You turn on the faucet and out comes clean, fresh water – ready to use for drinking, cooking, and bathing. But what if that suddenly changed? What if your water was contaminated and unsafe to drink?  

Suddenly, you would realize just how important clean water is! Thankfully, there are ways to protect yourself and your family from contaminated water, including installing an under-sink water filter. Read on to learn more about these filters and why they may be a good option for you. 

What is an under-sink water filter? 

Under-sink water filters are a type of filtration system that purifies drinking water. They can be used on a variety of faucets, and some modern under-sink units have been designed to work with only cold-water lines. The popular Glacier Point SE1W-PR is one such example. Historically, most under-sink water filters have required the use of both cold and hot water lines, though this is slowly changing. 

Basic under-sink units are installed on top of the plumbing that feeds into your sink, whereas under sink reverse osmosis systems are connected underneath the sink to a dedicated line running from the RO membrane. The RO membrane is a device that removes a high percentage of harmful contaminants from water by forcing it to go through a semi-permeable membrane. This process is called reverse osmosis, and most RO systems are installed underneath the sink because they require a dedicated line running from the RO membrane during installation. 

Why do I use a water filter? 

To be honest, I am not sure what the tap water in this city is like. But there are many people who still don’t trust it. I mean, just look on the Internet at all the stats on how many toxins there are in tap water. 

Plus, I have heard that it is not safe to drink straight out of the tap because there are some serious concerns about Legionnaire’s disease bacteria getting into your lungs if you use a regular faucet for this purpose. 

But I don’t care about any of that. The main reason why I have this water filter is so that I can drink more water daily, for health reasons. Because I am not drinking soda anymore, there are some days when my new carbonated beverage of choice is filtered tap water. Which means that I would not be drinking enough water if I had not installed a filtration system. 

Benefits of using an under-sink water filter 

Most people are aware of the health benefits of drinking enough water each day, but some don’t realize that their water supply can also impact their overall health. 

Drinking tap water is often not recommended because it can contain impurities like lead or chemicals like chlorine and fluoride. Bottled water is one way to address this concern, however bottled water can be expensive and creating a supply of it can take a toll on the environment. Fortunately, a solution exists that provides clean drinking water at a fraction of the cost and impact of bottled water – an under-sink water filter. 

Before buying one, it’s helpful to be aware of some benefits associated with using an under-sink filter. 

They filter out impurities from the water supply 

An under-sink filter is designed to remove contaminants from a water source. It can trap heavy metals, chemicals and other substances that make the water unsafe to drink. As a result, it provides a cleaner, healthier alternative to tap water. Bottled water doesn’t undergo the same level of filtration that under-sink water filters do, so it’s generally less pure. 

They reduce chlorine in the air 

Chlorine is a chemical added to tap water to kill harmful bacteria and other microorganisms. Unfortunately, this process produces a distinct smell and taste that most people find unpleasant. An under-sink water filter will reduce the amount of chlorine in the air around it, making everything smell and taste better. 

They’re more affordable than you might think 

An under-sink water filtration system can be an important investment for your home or office. Although they can cost hundreds of dollars, they only require a one-time payment and save money in the long run.  

Bottled water can be expensive, especially when it’s regularly consumed throughout the day at work or school. Even if you bring your own refillable bottle, that still requires time and energy to keep filled and clean. 

They can improve production quality. 

The effects of an under-sink water filter on the flavor of your food depend on which system you buy. They can reduce heavy metals like lead and mercury, however. Lead exposure is particularly dangerous because it accumulates in the body over time, gradually weakening bones and organs until irreversible damage occurs. 

They’re more environmentally friendly than bottled water 

If you’re concerned about the environmental impact of using bottled water, an under-sink water filter is a great alternative.  

They reduce the need to purchase bottles, which saves money and reduces your carbon footprint. With one of these installed, you can drink tap water at home or work without worrying about its purity. 

Some are small and discreet 

Under-sink water filters vary in appearance, but some of them are small and easy to install without making a big impact on the space they’re in. Some even mount directly under a sink instead of taking up valuable countertop or floor space. 

They reduce stress. Now you can get back to concentrating on work or other tasks, instead of worrying about the safety of your water supply. 

They have a wide range of uses 

The best under-sink water filters are versatile tools that can be used for more than just drinking water. For example, some models can filter ice cubes or provide filtered water for cooking. If you use distilled water in a humidifier in your home, an under-sink water filter can reduce the amount of minerals and other substances in it. 

They offer long-term value for money. 

Although you might spend hundreds of dollars on an under-sink water filtration system, they provide benefits for years to come. By drinking cleaner, safer water and reducing the amount of plastic bottles you use, you’ll see a noticeable difference in your health and environmental footprint. 

They’re more effective than pitcher filters 

If you’ve considered trying a pitcher filter instead, beware that they don’t provide as much filtration power as an under-sink model. Like bottled water, they don’t remove chemicals or heavy metals from the water. A pitcher filter might be a good alternative if you only need filtered drinking water occasionally, but for regular use an under-sink system is a better choice. 

They make a great gift for anyone who cooks, or drinks filtered water regularly 

An under-sink water filter system makes a thoughtful and useful gift for the health conscious people in your life. Many of them offer delicious-tasting water that’s safe to drink and can be used in place of bottled water. 

They reduce the need for plastic bottles 

Buying a reusable water bottle is a great way to save money, as well as eliminate the environmental impact of disposable plastic bottles. However, it still requires you to keep track of your bottle and remember to bring it with you.  

An under-sink water filter eliminates the need for an extra bottle, saving you money on buying disposable bottles while also reducing your environmental impact. 

Many models come with different filters to fit your needs 

 If you’re not sure what type of under-sink filter will best fit your lifestyle, many of them come in different sizes and models. For example, one model might have a carbon filter for reducing chemicals and a KDF filter for reducing heavy metals. 

They can increase the value of your home 

In addition to protecting the health of your family, an under-sink water filtration system also makes your home more valuable because it meets certain safety standards set by the EPA. 

It is true that they are expensive, but under-sink water filter systems can be a smart investment if you need filtered drinking water regularly in your home. They also reduce the amount of plastic bottles in landfills and eliminate the need for disposable filters like those used in pitchers or faucet attachments. By looking at the long-term value you’ll gain from an under-sink water filtration system, it’s easy to see that they’re well worth the price. 

They’ll help make your tap water safe for drinking 

An under-sink water filter system makes your tap water safe for drinking by removing harmful substances like chlorine, lead and mercury. Once you install your system under your sink, you’ll be able to enjoy delicious drinking water without the need for bottled water or disposable filters. 

They’re safe for pets 

An under-sink water filter removes harmful chemicals, metals and other substances that can be dangerous if consumed by humans. However, it is perfectly safe to drink water filtered by an under-sink water filter system if you have pets because there’s no risk of them consuming harmful substances that the filtering process removes. 

They’re easy to install and maintain 

  Your home already has a sink, so installing your under-sink water filtration system is easy. Once it is installed, you’ll enjoy clean drinking water without replacing expensive filters or spending your time shopping for bottled water. 

Some models come with an instant hot water feature 

  An instant hot water feature on some under-sink filtration systems makes the water flow out of your faucet over 200 degrees Fahrenheit. This is an economical and efficient way to enjoy instant hot water. 

Some models include a filter for fluoride 

  Fluoride can cause dental problems in some individuals, so you might want to choose an under-sink water filtration system with a fluoride filter. Fluoride filters help reduce the risk of developing cavities and improve the health of your teeth. 

They are compatible with most sinks 

  An under-sink water filtration system is compatible with most sinks, so you don’t have to worry about having a special type of sink before making this purchase. Just make sure that the connection for the faucet comes with correct adapters for your particular tap. 

They reduce the need for disposable filters 

An under-sink water filtration system eliminates the need for disposable filters like those used in pitchers or faucet attachments. By looking at the long-term value you’ll gain from an under-sink water filtration system, it’s easy to see that they’re a cost-effective addition to your kitchen. 

How to install an under-sink water filter 

To install an under-sink water filter, you must first shut off the water supply to the faucet.  

If you’re installing a basic under-sink unit, unscrew the damaged aerator and replace it with the new one that comes into your kit.  

If you’re installing an under-sink RO system, find where your incoming line is connected to the plumbing (most likely underneath your sink), then shut it off.  

You can do this by turning the water supply valve clockwise until it stops or sticking a flathead screwdriver into the “collar” of the connection and turning counterclockwise until it turns off. 

Underneath your sink, unscrew the coupler that connects your incoming line to your plumbing.  

Slip on a wrench or socket set and use the appropriate size to get a good grip on your line.  

While keeping one hand on your waterline connection, unscrew it by using your other hand to rotate the wrench or socket clockwise. Pull out the line if necessary until you can see where it connects underneath your sink. 

If you’re installing an under-sink water filter, remember to replace the PVC line with 1/4″ tubing for your reverse osmosis system (if you’re installing a generic under-sink unit, follow the instructions that came with your kit). If you’re using an under-sink RO unit like the Glacier Point SE1W-PR, unscrew your old line and connect the new 1/4″ tubing line to it. If you’re using an under-sink water filter, make sure your faucet has a dedicated water supply line running from the filter (most do), and attach it according to your kit’s instructions. 

Turn your water back on at the bottom of your sink by turning counterclockwise on your water valves. Turn it on either clockwise or counterclockwise; both ways will open the valve and let water flow through. Check for leaks by turning off your cold and hot water supplies at the valves and letting a few drops of water fall from the faucet. If there is no leakage, you’re all set up! If there are leaks, close the valves and check for leaks again. If you still have problems, call a professional to have them do it for you. 

Adding an under-sink water filter is not complicated once you’re familiar with plumbing skills. With just a little practice, tightening your connections will become second nature to you! If you’re planning on installing a reverse osmosis system, make sure you have a dedicated line from the RO membrane. If you’re installing a basic under-sink water filter, buy one that comes with an aerator to attach to your faucet. Have fun and enjoy fresh filtered water! 

How to maintain your under-sink water filter 

At this point, I assume that your water purifier is working properly and you’re steadily drinking clean, filtered water. [If not], read our [other article] on how to fix under-sink water filters. 

And now we have got into the details of how to maintain your filter. The best way to do this is to check the filter every month or so. 

Sometimes, all you need to do is to press down on the button at the top of the filter and hold it down for one second. Then, take a glass from your cupboard, unscrew the lid, turn it over, click the button again for another second, and fill the glass with filtered water. That’s it! 

Sometimes, you need to unscrew the lid, take out the filter cartridge, and rinse it in cold running tap water. There will be either a white or brown ring around the top of your filter cartridge. If so, simply wash this off in running tap water. Next, dry the top of your filter carefully with a paper towel. 

Other times, you may need to scrub the filter cartridge in cold running tap water with a bottle brush or an old toothbrush. If that doesn’t work, then soak it in clean water for about 30 minutes and try scrubbing it again. You should be able to remove whatever is on the filter by this means. 

Occasionally, your cartridge may seem completely clogged up and there seems to be no way for water to even get through. If that is the case, do not force it! Go buy another cartridge right away. But if you have an extra one lying around, you can try to take it out and soak it in clean water overnight. When you put the cartridge back in, leave it for about two minutes before you press down on the button at the top of your filter to get any filthier water out of the cartridge. 

In rare cases, your under-sink water filter may stop filtering water completely. If so, it’s probably because there is a break in the seal around the cartridge. The only way to fix this is to buy another cartridge and install it. Ask for a refund or replacement at least once before you purchase a new one! 

That’s about it. Maintenance of your water filter should be very simple and quick. Stay with your tap water until it stops flowing, press down on the button at the top of your filter for one second to let water flow through again, wait two minutes, and drink! 

Things you should know about an under-sink water filter 

1. The installation: Under-sink water filters contain a faucet and a main unit, and the connections and piping for this so that clean drinking water can be provided. It is essential to note that under-sink water filters must be installed professionally, and by a licensed plumber. 

2. The replacement cartridge: Filters should be changed every six months to two years depending on the type of filter you have; it is essential that this is carried out as otherwise your water could potentially become contaminated with bacteria growing in the old cartridges. 

3. The cost: Under-sink water filters range in price, and it is essential that you get a water filter system that suits your budget. 

4. The ease of use: Water filtration systems should be easy to use and shouldn’t require any special tools; these are included with some models, but not all. If the model does not include them then they can usually be purchased separately. 

5. The benefits of under-sink water filters: There are many benefits, but to list a few they are that clean drinking water is provided almost instantly, there is no need for storage space for bottled water which saves money and reduces plastic waste, and the filter systems save time as changing the cartridge only takes a couple of minutes. 

6. Specifications: Under-sink water filters can come with a wide range of specifications, and these should be researched before purchase; some useful specification aspects to research include the size and shape, and whether they require power or if they work on gravity alone. 

FAQs about Everything You Should Know About Under Sink Water Filter

An under-sink water filter is a filtration system that attaches to the faucet of your kitchen sink. It uses activated charcoal and/or other filtration membranes to remove harmful pollutants from drinking water, making it safe for human consumption. These filters are effective in removing chlorine, other chemicals, and many microbiological contaminants. 

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.

Under-sink filter systems are effective in removing various harmful pollutants from drinking water. The pores of activated charcoal can trap as much as 40% – 50% more impurities than standard carbon filters. In addition to their effectiveness, under-sink water filters are comparatively inexpensive than other filtration systems such as reverse osmosis and distillation. They can also be easily installed under an existing kitchen sink. 

Water may contain harmful levels of chemicals, heavy metals and/or microbiological contaminants that could affect our health. Lead, pesticides and DDT are likely to be found in the water of old buildings. Nitrates and nitrites can derive from animal wastes or chemical fertilizers. Other chemicals that may contaminate our water are chlorine, arsenic, asbestos fibers, radon gas, herbicides and salt run-off. All these substances are probable human carcinogens. 

No. Most public drinking water supplies are treated by chlorination, which can lead to formation of many potentially harmful chemicals like trihalomethanes (THMs). These chemicals are known as priority pollutants and have been found to be associated with bladder cancer, colon cancer, rectal cancer and heart disease. 

THMs refer to a wide variety of chlorinated organic compounds such as chloroform (CHCl3), bromodichloromethane (CH2Cl2Br) and dibromochloromethane (CH2BrCl2). They are formed when chlorine in the water reacts with organic compounds and inorganic substances. These organic chemicals may be naturally occurring or due to contamination from industrial wastes and herbicides. 

Trihalomethanes can be removed effectively by activated carbon filters. Activated charcoal, commonly called activated carbon, is a highly porous material that can absorb contaminants at the molecular level. It also has a high resistance to chemical attack and can be regenerated multiple times simply by heating it in an oven. 

There are several types of filtration systems available that treat contaminated water. These include filters for under-sink, refrigerator or ice makers, whole house, countertop, faucet-mounted and pitcher-style filters. 

Activated charcoal is made by treating pieces of coal with oxygen to form millions of tiny pores between the carbon atoms. The surface area of one gram of activated charcoal is equal to an incredible two football fields! This great level of exposure makes carbon an ideal material for filtration. 

There are several types of filters available on the market today. Some can be used with existing faucets while others require you to have a separate hole made in your kitchen counter for installation. The three main types of systems are under sink mounted filters, whole house filters and under counter filters. 

  1. Under sink-mounted filter – This is a common type of filtration system that is easily installed on an existing kitchen faucet. It connects to the cold-water supply of your plumbing directly by a dedicated line or a T junction at the supply pipe. The filtered water is stored in a reservoir tank where it is chilled before being dispensed.

The advantage of this type of filtration system is the ease with which the installers can connect it to your plumbing by simply tightening its fittings. It requires no additional hole to be made on your kitchen countertop for installation. The disadvantage is that it can slow down water flow which may not be suitable for high-rise buildings where the plumbing distance is too long. 

2) Whole house filter – This filtration system is best suited for homes which do not have a separate pipeline supply of filtered water to each faucet. The system consists of one point-of-use device that treats water for the entire household. The intake of the filter is plumbed to a dedicated line from your plumbing system where it can be easily attached to the faucet in any convenient location. This type of filtration system is more expensive when compared with under sink mounted filters but there are no problems with water flow. 

3) Under-counter water filter – This type of filtration system is installed below the kitchen counter and has a dedicated faucet for drawling filtered water. When comparing under-sink filters, this type of filtration system offers a more convenient location to attach your faucet as it does not require any drilling on your kitchen countertop. 

There are two main water filter change standards currently used in North America namely ‘Stage’ and ‘(HF) High Flow’. Stage filtration cartridges should be changed every 4 months or 200 gallons (if filtered water is used more than 5 times a day). High-Flow filtration cartridges can be changed every 6 months or 500 gallons. 

It is very easy to install and there will be no need for an additional faucet. You just take off your old aerator (on the end of the faucet), attach the new filter unit, and screw on your new one instead. Then you simply connect a hose to the bottom of unit and put a rubber washer at the end. This is what will slide onto your faucet so that you can have access to filtered water all the time. 

There are clear instructions included with the product. Plus, there are many videos on YouTube if you need help. 

There are no cartridges to replace or anything like that. Just backwash your cartridge once a month by putting white vinegar into the system and then press the recirculate button for 30 seconds. And that’s it! This will clean out most of the calcium particles, which means better tasting water. If there is still sediment in your water, you may need to do this 2-3 times. 

Keeping it clean is very important because calcium can build up rather quickly and hence reduce the life of the unit itself. I use a towel to wipe everything down about once a week as well as when I backwash (if you have hard water). 


Under-sink water filters are a cost-effective alternative to large household water filtration systems.  

They work by filtering the incoming tap water through multiple layers of activated carbon, which absorbs and removes contaminants from the stream before it is passed out as clean drinking water.  

If you’re looking for a way to improve your home or business’s quality of life without going broke in the process, read on! We have compiled this article with all our top picks for under-counter filters that will suit any budget – no matter how small. With so many options available, we hope you find just what you need. 

Related Posts

Why Trust Us

You will find what you are looking for at Largo Bar and Grill. From classic to luxury brands, you'll find both. We will help you to select appliances that fit your needs, budget and lifestyle. Whether you want to stop by to learn more — or plan to make a major purchase — we’ll treat you like family and assist you every step of the way. Shop with us today to receive friendly and experienced help along the way.