The 6 Types of Water Filters: Whole House, Faucet & More

Types of Water Filter


Even if it is sparkling clear, water usually contains contaminants, which are either harmless or harmful. The harmful ones include pesticides, bacteria, viruses, and salts, just to name a few, and need to filter these out to make the water safe for drinking.

However, there are many types of filters in the market, which incorporate the use of different filtration technologies to purify the water. All this information is laid down below to give you a clear picture of how these systems work.

Why Should You Use Water Filtration Systems at Home?

To understand why this is important, you need to consider the alternatives. Of course, it’s not advisable to drink water straight from the well or municipal supply. Therefore, the remaining alternative is bottled water.

Bottled water is actually very good because it is filtered and treated, but it is expensive in the long run. Installing a filtration system at home is expensive at first but gets cheaper in the long run.

It is also inconvenient to have to go buy bottled water all the time, especially if you have many people in the household.

Lastly, these bottles are not very safe for the environment because they are made using plastic. Therefore, the logical thing to do is install a filtration system.

Popular Filtration Technologies

Popular Filtration Technologies


1. Reverse Osmosis (RO)

Osmosis is a process through which molecules in a solvent tend to move from a less concentrated solution to a more concentrated one through a semipermeable membrane.

Reverse osmosis is the opposite of that. Since the process goes against the natural flow, it involves the use of a high-pressure pump, which forces contaminated water through a semipermeable membrane.

This membrane has very small pores that only allow water molecules to pass through and therefore, water moves from a more concentrated solution to a less concentrated solution (reverse osmosis), leaving the contaminants behind. 


  • Separates sediments from water
  • Purifies water by blocking germs from penetrating through the membrane


  • Expensive to set up
  • Bulky hardware
  • Wastes quite a lot of water (approximately only 1/3 of the water is purified)

2. Sediment Filtration

Sediment filtration incorporates the use of mechanical filters, which trap all physical contaminants (solids) that are suspended in the water. These include mud, rust, silt and other forms of debris.

The technology uses materials such as ceramic, melt-blown polypropylene or pleated polyester, which have multiple pores that don’t exceed 100 microns in size. The filter only allows particles that are smaller than the pore to pass through.

Depending on the material used, some can be treated using silver to eliminate bacteria. The only problem is that sediment filtration is not as effective as reverse osmosis because some contaminants manage to penetrate through.

Therefore, it is usually used as the first point of contact in a series of filters to prevent sediments from getting to the other systems, such as RO downstream. On the bright side, such filters are very affordable.


  • Affordable
  • Doesn’t require a pump or electricity to run


  • Does not eliminate all contaminants

3. Activated Carbon Filters

As the name suggests, this technology is developed using organic compounds that have a high carbon content such as coal, peat, and lignite. The filters are very similar to the sediment type because their primary objective is to trap sediments and other large particles.

However, they have a slight advantage over the latter because they are designed to have many pores for better filtration.

Additionally, carbon eliminates bad odor and reduces chemical contaminants like chlorine, leaving water with a better taste. On the downside, this type does not kill harmful germs.


  • Affordable
  • No pump or electricity is required
  • Improves the smell and taste of water


  • Does not eliminate viruses and small bacteria

4. UV Water Filter

UV filters have a UV light bulb as the main component. How do they kill germs? Ultraviolet light produces germicidal energy that kills and destroys disease-causing micro-organisms by attacking their DNA.

This eliminates the ability of the organisms to reproduce, which makes them harmless. It destroys up to 99.99% of these viruses and bacteria, making it the most effective non-chemical-based water purification solution.

However, for it to work effectively, the water must be clear so that the UV light can penetrate through to the end. Therefore, you need a sediment or an activated carbon filter (or both) to clear out the suspended particles in water before it goes into this one.


  • Chemical-free
  • Kills disease-causing germs (viruses, bacteria, protozoa, etc.)


  • Does not provide mechanical filtration
  • Requires clear water

5. Water Distillation

Water distillation is a very effective method of filtration because it involves heating. Water is boiled into steam then the steam is cooled back to liquid by a condenser as it makes its way into a collection jar.

The heat kills all germs and leaves salts, sediments, and other contaminants back in the boiling flask. However, even if very effective, the process requires a lot of energy and takes a long time to purify a large amount of water.

Therefore, it is not recommended for large scale or large family use. On the bright side, cartridge or filter media replacements are not required, making it almost entirely maintenance-free.


  • Effective germ-killing heating process
  • No cartridge replacements are required


  • Slow process
  • Requires a lot of heat energy

6. Water Ionizer

Ionization utilizes electrolysis to produce alkaline water that is rich in anti-oxidants, is smooth to the skin and has great taste.

Since the process uses positive and negatively charged plates, acidic water is also produced and this can be used for cleaning and disinfecting purposes.

Some water ionizers give you the option of setting the pH level in the water output for more customization. However, the process does not filter the water mechanically, which means sediments won’t be removed.


  • Produces rich anti-oxidant alkaline water
  • Produces acidic water for cleaning and disinfecting
  • Offers pH customization


  • Does not filter out sediments

7. Activated Alumina

Activated alumina filters contain bauxite, which is basically a highly porous and adsorptive aluminum oxide rock.

This compound is called “activated” because it grabs up to 99% of fluoride atoms in water, making it very effective at treating fluoridated municipal water.

The compound also absorbs arsenic, thallium, and selenium, leaving water tasting as natural as possible.

However, the process does not eliminate sediments and does not kill disease-causing germs. It is, therefore, best used with other technologies such as UV and sediment filtration.


  • Absorbs up to 99% of fluoride atoms
  • Removes arsenic, thallium, and selenium


  • Does not kill germs
  • Does not eliminate sediments

Types of Water Filters for Home Use

With all these technologies, the different types of water filters incorporate at least one of them for the job. Let’s see how they fare against each other!

Best Water Filter Pitcher

1. Water Filter Pitcher

Pitchers have the main benefit of being small, compact and lightweight for easy portability. Additionally, they are very affordable and no installation is required because they come as complete units.

However, they usually provide very basic filtration that consists of a sediment filter or an activated carbon filter or both. They also have a small collection jar and are therefore ideal for filtering small amounts of water for cooking or drinking.

The filtration media is usually placed on the upper part of the jug where you fill with water. This then drips down to the collection jar at the bottom after going through the media. 


  • Compact and lightweight
  • Affordable
  • Requires no installation


  • Small capacity
  • Provides basic filtration (does not kill germs)

Recommend: AquaGear Water Filter Pitcher

Best Countertop Water Filter

2. Countertop Water Filter

Countertop filters are usually very bulky but with this, they house a bigger cartridge. This means you can use them for a long time without requiring a replacement.

Additionally, some varieties come with multiple filters because one is not enough to do all kinds of purification. For instance, you might get a cartridge, activated carbon and UV filter combination, which is very effective.

Apart from that, they are fitted with faucets and due to their large capacity, they can handle a large amount of water at high pressure.


  • Large cartridge; requires less frequent replacements
  • Multiple filter variety options
  • Faster and handles more pressure than a faucet filter


  • Occupies a lot of counter space

Recommend: Apex MR-1050

How to Buy the Best Under Sink Water Filter

3. Under Sink Water Filter

Under sink water filters are the most commonly used type because they offer a minimum of 3 stages of filtration. This includes reverse osmosis, UV, activated carbon, cartridge, and others for mechanical, chemical and biological filtration.

The actual term here is purification (not filtration) because the units are designed to kill germs, producing water that is very safe to drink and to cook with.

On the downside, the filters are very bulky, expensive and can be challenging to install. However, by being installed under the sink, bulkiness is not a big issue.

The benefit though is that the large size means more water processing capacity. As a result, they have a faster flow rate as compared to countertop filters.


  • Effective 3 or more filtration stages
  • Large purification capacity
  • Hidden under the sink


  • Expensive
  • Complex installation process

Recommended: iSpring RCC7AK

How to Install a Faucet Water Filter

4. Faucet Water Filter

As the name suggests, a faucet water filter is installed on the faucet and water passes through its filtration media before getting into your glass.

That said, the filter’s filtration media usually consists of a non-woven filter cartridge and activated carbon. The cartridge is responsible for trapping dirt, mud and other sediments while activated carbon eliminates odor and chemicals such as chlorine.

This type is more convenient to use as compared to water filter pitchers because no refilling is required.

However, it is important to note that for the best results, you should run the water at low pressure so that it takes a long time passing through the carbon for better filtration.


  • Easy and convenient to use. No constant water refilling is required


  • Works best with slow-moving water

Recommend: Culligan FM-15A

​Types of Shower Filter

5. Showerhead Filter

Showerhead filters are very similar to faucet filters, with the only difference being that these are fitted on your shower head. Most of them contain activated carbon and alumina, which filter out chlorine, fluorine and eliminate bad odor.

Therefore, they are ideal to use in areas where the water has these contaminants. However, the media does slow the flow of water, resulting in a low-pressure output.


  • Eliminates chlorine, fluorine and bad odor


  • Reduces water flow

Recommend: AquaBliss SF220

How to Buy the Best Whole House Water Filter

6. Whole House System

Lastly, instead of having all these different filters for the sink, faucets, and shower heads, it makes sense to have one for the whole house, especially if you use well or borehole water.

Whole house filtration systems typically feature multiple filtration technologies inside, which trap sediments and kill germs for all-round purification. Additionally, they can process a lot of water at a time as it comes in from the supply lines.

If you have a municipal water supply, you can get a scaled-down version with filters for eliminating chlorine and sediments, which would be cheaper and easier to maintain.

However, the full-scale models are very costly and require a complex installation process inside your tank.


  • Offers all-round filtration and purification
  • Large filtration capacity


  • Expensive
  • Difficult to install

Recommend: Culligan WH-HD200-C


1. Is NSF Certification Required?

NSF certification is recommended but is not a must-have. The certification shows that the filter meets the organization’s threshold for filtration performance and that the performance stats are not exaggerated.

However, this certification does not guarantee quality. A filter might be NSF certified and performs very well as first but then wears out very quickly.

2. How Do I Know Whether the Filter Cartridge Is Clogged?

The most effective method is to measure the filter’s output PSI when the cartridge is new then measure regularly for comparison purposes.

When new, the pressure should be low but with debris, wear and tear, it increases. For instance, if you find that the pressure is 5x as high a few months later, then you need to clean or replace the filter.

3. How Long Do I Need to Replace My Water Filter Cartridge?

The lifespan of a filter cartridge is determined by its frequency of use. Other than that, since cartridges deal with mechanical filtration, if the water contains a lot of sediments, then a replacement will be due at a much sooner date as compared to when dealing with clearer water.


As you can see, there is a wide variety of water filters with different filtration technologies to choose from.

Considering that water cannot be 100% free from contaminants, it is recommended to use at least one of the basic types listed above, such as the water filter pitcher, for drinking water.

However, for the best water quality all-around home use, we recommend the whole house filtration system. Though expensive, this system ensures that the water coming out of your faucets, shower heads and all other taps is purified enough for safe use.