Water Filters 101 | Everything You Need to Know

Water Filters Everything You Need to Know

Water is life, and without it, we won’t be able to survive for long. But have you ever thought that water itself could be the source of many of our woes?

Proper hydration is one of the essential requirements for the well-being of every living creature on Earth. Sadly, it’s estimated that most of us humans drink much less than the required amount of water.

The trouble is, just as not drinking enough water can be detrimental to your health, drinking water from dubious sources can also be harmful. Hence, to ensure that you and your family are drinking clean water, it’s essential to get a water filter installed at home.

But this task is easier said than done. With a large number of filter types and technologies available on the market, choosing the right one can be a real hassle. Therefore, to help you get through this problem, we’ve decided to create the ultimate guide on water filters.

And we are going to begin with the very basics.

Water Filters 101

Water Filters 101 Everything You Need to Know 5

What Is A Water Filter?

This might seem to be a silly question; after all, isn’t a water filter a device that, well, simply cleans water? But dive deeper, and you’ll know that there’s a lot more to this device than meets the eye.

Put simply, a water filter is a device that allows you to decontaminate water by using different layers or barriers. These barriers may be physical, chemical, or even a combination of the two.

Water filters serve the primary purpose of making the water we drink free of pollutants, harmful microorganisms, and toxic chemicals that may have seeped into the water source. There are multiple advantages of using water filters (we’ll delve into that later in this guide), such as removal of heavy metals like arsenic and lead.

Filtration can even serve to make water taste and smell better than it was before. And even though installing a water filter may seem like an upfront investment, in the long run, it saves you a lot in terms of medical bills for water-borne ailments. And you don’t have to shell out much for those mineral water bottles either.

But surely you think that the water source in any developed nation is clean enough just to be used directly? Sadly, while that is a desirable feature, it is nonetheless lacking in most cases. Even in the USA, a large number of regions have reported a toxic water problem that needs to be tackled with urgency.

Still not convinced? Then read on to find out more.

Do We Really Need Water Filters?

We’ve already given you a glimpse of why we need water filters, but here we are going to take a detailed look at the necessity for the same.

Usually, our home water lines are tapped into government supply channels. Now, this water is generally purified at water purification plants that clean the water before sending it to our houses. But surely, that makes the water clean enough to be directly used, right?

Sadly, that is far from the truth. While it’s undeniable that the water that reaches your home is purified to a degree, that doesn’t make it the epitome of cleanliness. And this is the reality of any water supply system, no matter how large or small.

But does that mean that the authorities are forcing us to consume contaminated water? Far from it; when the water is quality tested before sending it to our homes, it’s actually quite clean. Often the test results are satisfying enough to warrant direct consumption.

Where does the real problem lie then?

Water Filters 101 Everything You Need to Know 3

It’s In The Pipes

The real source of the problem lies in the supply lines that crisscross to your home across the town. Usually, water treatment facilities are located at the very edge of the city; this means the water has to travel a long way before reaching the end-user. And this entire route is covered by means of supply lines that are years, if not decades old.

These pipes have been sitting there for a rather significant period, and as a result, they have become tainted with dust, rust and even biological contaminants. And when the water travels through them, these contaminants get mixed into it.

This is why the water that reaches our home taps is discolored or even has strange odors. And as we all know, water in its purest form is a colorless, odorless, and tasteless liquid. So any deviation from that standard can usually be taken as an indicator of contamination.

The next vital reason why you should be using a filter at home lies in the very purification methods that are being used in the government filtration stations. Most often, the water is decontaminated by chlorination; this, of course, has the desired effect of killing off all microorganisms.

But along with that, the chlorine can also react with heavy metals present in the water and form harmful compounds that can cause diseases such as cancer. 

Plus, chlorine itself is a hazardous element, and in unsafe levels can be dangerous for human consumption. And while you might think that’s enough, the story’s not over yet. 

The Little Things Matter

Conventional filtration processes cannot get rid of harmful microorganisms that cause diseases such as diarrhea and cholera.

Another reason for using filtration units at home is the rampant use of pesticides that have a long half-life. Pesticides that used heavy metals have been banned for some time now, but the trouble is that these elements can persist in the environment for decades. And they may have very well seeped into the supply pipes that carry the water to our homes.

Further, metals such as lead have a substantial probability of being present in the supply lines. These metals can easily bioaccumulate in our bodies and result in multiple diseases, such as neural disorders and kidney damage.

Taking all of the above into consideration, it’s evident that a water filter is not a luxury but a necessity. And unless you have one at home, you can’t be sure about the safety of the water that flows out through the tap.

But which one should you buy? There are quite a few varieties of water filters that you can choose from. In the next section, we are going to take you through all the different types of water filters that you need to know about.

Water Filters 101 Everything You Need to Know 6

Various Types Of Water Filtration Techniques You Can Choose From    

In this section, we are going to take a tour of all the major water filtration types from which you can choose the best one for your home. We are also going to go through the pros and cons of each type and make sure you get a good idea about which one to go with.

Sediment Filtration

These are the most common types of filtration systems that you can find and rely on physical barriers to remove contaminants. Sediment filters are mostly used for removing the larger particles in water, such as sand, dust, and silt.

These filters are usually made from polypropylene, or pleated polyester, and have small pores in the size range of microns—usually, the smaller the pores, the better the filtration capabilities.

The principle behind their operation is pretty straightforward: as water passes through the filter, particles which are larger than the pore size get blocked, while the rest of the water passes through. For this reason, sediment filters are usually used as pre-filter systems to protect the filtration unit from getting clogged by large particles.

Some of the advantages of sediment filters include a low cost and easy replaceability. Also, sediment filters come in a variety of sizes, which ensures that particles of multiple granularities can be removed with ease.

However, it must be remembered that sediment filters alone cannot hope to purify water completely. And they cannot effectively block or remove biological contaminants. For this reason, these filters must be combined with other filter types to get clean water that tastes, smells, and is as harmless as water should be.

Activated Carbon Block Filtration

Activated carbon is a form of the element that has been processed to maximize the adsorption surface. This simply means that the material has a large number of pores on the surface, which help to trap contaminants and thus purify the water.

Activated carbon adsorption is a physicochemical process that removes impurities such as excess chlorine, volatile organic compounds, and microscopic water cysts. It also provides a high degree of protection against bacterial growth.

Affordable and with a high performance-to-cost ratio, activated carbon filters are excellent at removing chemical, physical as well as biological contaminants from water. They provide an exceptional water flow rate and have a long life.

Also, they don’t require a power source to operate and can be easily used with other filtration techniques to achieve enhanced purification capabilities. Plus, they can be customized and used in multiple applications. However, they can’t remove viruses and don’t have a very high water flow rate.

Granular Activated Carbon Filtration

The principle of operation behind granular activated carbon (GAC) filtration is similar to activated carbon block filtration. The primary difference between the two is that while activated carbon block filtration uses powdered carbon, granular activated carbon filters utilize larger, more loose carbon granules.

Due to the larger granularity, these filters have a better flow rate than the powdered carbon filters but have lesser adsorption capabilities. Therefore, these are mainly used as pre-filters with other technologies to remove larger contaminants, and also to achieve higher chlorine removal rates. 

As these types of filters have a high water flow rate, they are most suitable for low-intensity, high-flow filtration systems. Some suitable candidates might be entry-level filtration systems, commercial filtration applications, and as a part of filtration systems that utilize multiple stages.

Being an inexpensive filter type that has considerable longevity, high flow and filtration rates, and minimal pH level change, GAC filters are slowly gaining in popularity. The only downside to these filters is that they can’t remove viruses, excess dissolved solids, and smaller sized contaminants.

Reverse Osmosis Filtration

Known fondly as RO technology, this water filter type has gained immense popularity in recent times, and with good reason. RO technology is based on the principle of osmosis, which governs the movement of particles from a region of lower to higher concentrations across a semipermeable membrane.

In the RO method, the technology is reversed, and the contaminants are forced to move from the region of higher concentration ( the water) to one of lower concentration. The movement is still across a semipermeable membrane that has pores in the range of a few microns.

As the pore size of the RO membrane can be as small as 0.0001 microns, they can easily trap and remove almost 99% of the contaminants that are usually present in drinking water. This includes microorganisms, dissolved solids, and viruses. RO filters are known to produce the cleanest form of drinking water, and as they are washed continuously they have substantial operational longevity. 

However, one of the downsides of RO filtration is that these types of filters are vulnerable to chlorine. Hence, RO filters usually require an activated carbon pre-filter to neutralize any chlorine present in the water. Also, RO filters produce a large quantity of wastewater in the course of the process. This naturally leads to slower filtration rates and higher costs.

Distillation Filtration

This is not exactly a filtration technique that is very popular for home use (you’ll know why soon enough). However, as we are talking about everything related to water filters, it’s best to go through the intricacies of this method as well.

The distillation process depends on the variability of boiling points between the water and contaminants. In this technique, the impure water is boiled using electricity to form water vapor. Now this vapor is separated from the impurities which remain behind.

Finally, the pure water vapor is allowed to condense and again forms pure water. Distillation as a process is considered to give the purest form of water, free from all dissolved as well as undissolved impurities. The only thing that distillation cannot get rid of is volatile organic compounds, which have a lower boiling point than water and will get into the vapor as well.

Now, since it is clear that distillation is the best way to get pure water, why is it not the most widely used? The answer lies in the process itself. Distillation requires specialized equipment and has a very low output. Plus, the method also consumes a large amount of electricity.

Another reason for not using distillation at home is that distilled water is not exactly fit for drinking purposes. Flat in taste, and without any minerals, this water can actually be harmful to the body if taken regularly. For this reason, distilled water use is mainly confined to industrial and laboratory environments.

Ion Exchange Filtration

Ion exchange filters use ionic removal to get rid of harmful ions that may be dissolved in water. In the Ion Exchange (IX) process, small, resinous microbeads act as a medium of exchange, and these function by trapping specific undesirable ions, while releasing the rest. IX can be used to remove harmful heavy metals ions such as lead, and replenish the water with safer mineral ions such as potassium.

Ion exchange filters are again classified into two types: the cation exchange type and the anion exchange type. The two processes are used for softening of hard water, metal removal and demineralization.

IX is a safe process that produces drinkable water; the technique requires relatively less effort to set up and has excellent flow rates. And the beads used in the system can be recharged for repeated use.

The flip side is that this process cannot remove biological contaminants, and has a high operating cost. Conjunction with other filtration techniques can help to improve such filters’ capabilities.

Ultraviolet (UV) Filtration

UV filters are yet again one of the most used water filters on the planet. These filters use high-frequency UV light rays, which are focused through a glass element to irradiate the water. This technology is most useful against biological contaminants.

Using UV filtration technology, most microorganisms like viruses, bacteria, and protozoa can be removed from water. The UV rays emitted from the lamp will either kill or deactivate these microorganisms.

Since this technology is based on light rays, it’s best to use it as the last component of a home purification system. This will allow the previous stages to remove all solid impurities that may hinder the passage of the UV rays.

Being a quick and reliable disinfection process, UV filters have gained popularity as the only means to kill off most microorganisms. With a low operating cost and very little required maintenance, UV is one of the best filtration techniques available.

However, it must be remembered that UV filters can only remove microorganisms from the water, and cannot work against dissolved or solid impurities. This requires them to be used in conjunction with other filtration techniques. 


This type of filtration method uses a mechanism that is similar to reverse osmosis (RO). Here, hydrostatic pressure is applied to force the contaminated water through a semipermeable membrane that is made from submicron hollow fiber. This ultrafiltration membrane is fine enough to filter out microorganisms and yet retain essential minerals.

However, ultrafiltration cannot effectively filter out dissolved solids in water, and hence it is best used with other filtration techniques such as reverse osmosis and activated carbon. Also, the ultrafiltration membrane has a high resistance against dissolved chemicals; it can also be used to remove dissolved chlorine from water.

Activated Alumina Filtration

Activated alumina water filters are made using porous aluminum oxide, which is highly adsorptive. This type of filter is mainly used to remove heavy metals such as thallium and arsenic. Activated alumina can also be used to remove fluoride from tap water.

The process involved is rather simple: the activated alumina is first chemically treated and initialized for use in the filtration process. Then, the water is passed through the alumina granules; this allows the contaminants to get adsorbed on the surface of the filtration medium.

Activated alumina filters are the best option for removing fluoride from water. However, the filtration medium requires periodic cleaning with a regenerating agent. Also, it does not protect against biological contaminants, and hence must be used in conjunction with other filter types to achieve all-round filtration capabilities.

Ionization Filtration

This filter type utilizes the principles of electrolysis to separate positively and negatively charged ions from water. This technique works by fundamentally changing the very structure of water molecules to produce antioxidant-rich ionized alkaline water, which is fit for direct consumption.

The process also produces ionized acidic water that can be used for industrial purposes. This filtration technique has the benefit that the alkaline water produced has a pleasant taste and is beneficial for your health. 

However, the entire process requires a power supply to work, and this might result in pushing up your electricity bills. Also, the filtration capacity is rather low as this method cannot remove dissolved solids from the water. On top of everything, these filters are rather costly, and hence one might choose to avoid them altogether.

Ceramic Water Filtration

This is the last filter type on our list, but that doesn’t make it the least. In fact, this is one of the most inexpensive yet cost-effective methods of filtering water. These types of filters usually come in two variants: the pot filter and the candle filter.

The operating principle behind ceramic filters is simple: the filter has a large number of small pores which permit the water to pass through, yet block contaminants that are larger than the pore holes.

Ceramic filters are great at removing bacteria and protozoa; sadly, they are ineffective against viruses. Very often, silver is added to this type of filter to kill off bacterial contaminants.

These filters usually have a very long operating cycle and don’t require yearly filter replacements. However, they cannot remove chemical impurities from water and are prone to get dirty. Also, since ceramic is a somewhat fragile material, these filters can easily get damaged in handling.

Well, that was all about the different filtration techniques that water filters use to provide us with clean water. Now, let’s take a peek at the various models of water filters that are available to be bought.

Types Of Water Filters You Can Get

Pitcher Type Water Filter

This is the most common type of water filter and consists of a jug with two parts. The upper part has a chamber at the center that houses the filtration unit (usually activated carbon). You need to pour the water to be filtered in this section, and it comes out clean and accumulates in the bottom section.

From the bottom section, the water can be removed for use. Pitcher type filters are low on cost as well as maintenance and can be easily used on outdoor trips. However, they are limited in capacity and require frequent refilling.

Faucet Type Water Filter

This type of water filter is directly installed on the faucet and works by removing the contaminants from the water before the water comes out. As they are inexpensive and easy to install, these filters are very popular with homeowners. The only downside is that they slow down the water flow considerably.

Countertop Water Filter

Countertop filters are best suited for households that have a spacious countertop. These filters can easily connect with the faucet in your kitchen and provide a steady stream of filtered water. Faster than faucet based filters and without the limitations of pitcher filters, these often come with a faucet of their own.

Under Sink Water Filter

As the name suggests, under sink water filters are installed under the sink in your kitchen and make the water flowing out of the faucet clean for drinking and everyday use. These filters have much better flow capacities than the previously mentioned types but are also more expensive and tough to install.

Centralized Water Filters

This is the largest filter of them all and is installed at the main water tank. This filter type eliminates the need for individual filters at different locations. As can be surmised, they are also more costly and require professional installation.

Benefits Of Using A Water Filter

As promised, we are now going to elaborate on some of the many benefits of using water filters. And the most noticeable one is, of course, a reduction in the smell. Contaminated water can often have freaky, unpleasant odors. This can be due to the presence of chemical contaminants as well as biological ones; filtration can help to remove these contaminants.

So, why can’t we drink bottled water, you may ask? Well, there’s no problem with the water in these bottles, per se. But the trouble lies in the bottles themselves. Many mineral water bottles are made out of plastic that contains harmful components. These can often get into the water and make you sick.

Plus, drinking bottled water simply means that you are increasing the levels of plastic in the environment. And as we well know, plastics are posing dire risks to the environment, and us. For this reason, it’s essential to shun plastic bottles as much as possible and stick to filtered water.

Another reason why you should be filtering your water is to remove the chlorine that is added to it at the filtration plant. Chlorine is, by nature, a toxic element that is not particularly beneficial for us humans. So it makes sense if you install a filter to remove the chlorine from your water before drinking.

Along with chlorine, filtration can also remove other harmful substances from water, such as dissolved solids, heavy metals, and pesticides. These are substances which, when ingested, can bioaccumulate in our system and cause long term problems. Filtration can help to remove the same.

And for those of you who are still worried about the cost of buying a water filter, here’s an alternative point of view. While it’s true that water filters do require a certain upfront investment, they also save you a lot of money in the long run in the form of saved medical expenses. So it’s best to think of a water filter, not as a spend but an investment.

Finally, using a filter at home and in the office is one of the best steps that you can take to ensure the long term health and safety of yourself as well as family members. Water is one of the most critical components for survival, and it must be pure enough to allow us to lead a healthy life.


We began our discussion with an age-old adage: water is life. But if you stop to think about it, it’s still as relevant today as when it was first coined. Drinkable water is perhaps the most essential resource that we have at our disposal.

Yet, we humans, with our characteristic propensity for pollution, have managed to contaminate our water sources. And this makes life difficult on multiple levels for all living beings.

Therefore, to protect ourselves from the ill-effects of water pollution, it’s essential to use water filters at home and even in commercial spaces. By doing so, we can ensure our safety, as well as that of those around us.

What do you think? Do you have a water filter at home? Or maybe you are thinking about getting one? Whatever the case, be sure to let us know.

Till then, drink safe!

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Anna Vaughn

Anna Vaughn

Immense painting experience recommends Anna. She shaped The Little Painters, a small local painting workshop for children that invites the little ones to explore painting through simple and creative means in a safe, loving and extremely colorful environment. In her home panting studio she plays with all paint mediums but watercolor is her expertise.

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