Complete Guide To Water Filtration Systems

Water is essential to life, and the water we drink and use must be safe and healthy. Unfortunately, tap water can contain chlorine, lead, pesticides, and other contaminants that can harm our health. This is why most people see the need to have water filtration systems in their homes. 

In this comprehensive guide, we will explore the different types of water filters, how they work, what they remove, and where they are installed so you have everything you need to decide which is best for your needs.

Types Of Water Filters

Countertop Filters

Countertop filters are a convenient and affordable way to filter tap water. They come in various sizes, from small units that can be placed on a kitchen counter to larger units that can be placed on a stand. Countertop filters use activated carbon to remove contaminants from water. 

Activated carbon is a form of carbon treated with oxygen to make it more porous, allowing it to absorb contaminants from water. The water passes through the filter and is collected in a container below. 

Countertop filters can remove contaminants such as chlorine, pesticides, and other chemicals. Some countertop filters have additional filters that can remove heavy metals and bacteria. 

In general, countertop filters are easy to install and require no plumbing. The average price of countertop filters ranges from $30 to $200.

Types of countertop filters

Gravity countertop filters

These are the most popular type of countertop filters. They use gravity to filter water through different stages of filtration media, such as ceramic, carbon, and other materials. These filters remove many contaminants, including sediment, chlorine, volatile organic compounds, and heavy metals.

How they work

The water is poured into the top chamber of the filter and passes through the filtration media before reaching the bottom chamber, where it is collected for consumption. 

Countertop gravity filters are easy to set up and take care of, and they don’t need electricity or plumbing. They are also portable and can be taken with you when you travel.

Cost

The average price of a gravity countertop filter ranges from $30 to $150, depending on the size, type, and brand.

Countertop Faucet Filters

Countertop faucet filters are another type that attach directly to your faucet. These filters use carbon filtration technology to remove chlorine, sediments, and volatile organic compounds.

The filter cartridge of a countertop faucet filter can be easily replaced when it becomes clogged or exhausted. These filters are easy to install and remove and don’t require special tools or plumbing.

How they work

There are two variations of countertop faucet filters. 

1. Countertop dispensers. It dispenses water directly from the unit. You can control the flow of water by pressing a button or lifting a lever, and it will go through the filter before coming out of the spout.
2. Countertop diversion filters. It diverts water from your faucet and then returns it to the same faucet for consumption. When you turn the faucet, water will go through the filter before flowing back to the faucet and out of the spout.

Cost

The average price of a countertop faucet filter ranges from $20 to $100, depending on the size, type, and brand.

Countertop RO

Countertop reverse osmosis filters use the reverse osmosis process to purify water. These filters are designed to sit on a countertop and provide filtered water on demand. They are a popular option for those who want high-quality, purified water without needing a permanent installation.

The reverse osmosis process uses a semi-permeable membrane to filter out contaminants from the water. The membrane has small pores that allow water molecules to pass through but block larger molecules, such as minerals, chemicals, and bacteria. The filtered water is then collected in a storage tank, ready for use.

How they work

Countertop reverse osmosis filters typically use a multi-stage filtration process, including pre-filters, membrane filters, and post-filters, to thoroughly purify the water. The filters may also use additional technologies, such as UV sterilization or alkaline enhancement, to further enhance the quality of the water.

Cost

The average price of countertop reverse osmosis filters varies depending on the brand and features of the filter. Basic models can cost around $100 to $200, while more advanced models with additional features such as UV sterilization and alkaline enhancement can cost upwards of $500 or more. 

When choosing a countertop reverse osmosis filter, it is essential to consider the initial cost of the filter, as well as ongoing maintenance and replacement costs.

Undersink Filters

Undersink filters are a type of water filter that is installed under the sink and attached to the water line. These filters are designed to filter water at the point of use, providing clean and filtered water for drinking, cooking, and other household purposes. Undersking filters are famous for those who want a more permanent and space-saving water filtration system.

Types

1. Activated carbon filters. These use activated carbon to remove contaminants from the water. 
2. Reverse osmosis filters. These use a semi-permeable membrane to remove particles, molecules, and contaminants from the water. 
3. Ceramic filters. These use a porous ceramic material to filter out contaminants and bacteria from the water.

How they work

Undersink filters connect to the main water line under the sink and filter the water before it comes out of the faucet. The water passes through the filter and is cleaned of contaminants before being dispensed for use. 

Undersink filters are typically installed by a plumber, but some models come with easy-to-follow installation instructions for 

DIY installation.

Average prices

Basic activated carbon filters can range from $50 to $200, while reverse osmosis filters can cost between $150 and $500 or more. Ceramic filters can go from $100 to $400 or more. 

Again, the average price of under-sink filters varies depending on the type and brand of the filter. 

Note: It is crucial to consider the initial cost of the filter as well as ongoing maintenance and replacement costs when choosing an under-sink filter.

Faucet-mounted Filters

Faucet-mounted filters are a type of water filter that attaches directly to the end of a standard faucet, providing filtered water on demand. These filters are popular for those who want to purify their tap water without needing a dedicated filtration system or installation.

Types

There are two primary faucet-mounted filters:

1. Basic faucet-mounted filters. These filters are the simplest and most affordable option. They typically use a single-stage filtration process, often consisting of activated carbon or ceramic filters, to remove contaminants and improve the taste and odor of the water.

2. Advanced faucet-mounted filters. These filters use a multi-stage filtration process to provide a higher level of purification. They may include additional stages for removing heavy metals, bacteria, and other contaminants and may also use UV or other technologies to further enhance water quality.

How they work

Faucet-mounted filters divert water through the filter unit as it flows out of the faucet. The filter removes contaminants, leaving only clean, fresh-tasting water flowing out of the spout.

Average prices

The average price of faucet-mounted filters varies depending on the type and features of the filter. Basic models can cost as little as $20 to $30, while more advanced models can cost upwards of $100 or more. 

Water Filter Pitchers

Water filter pitchers are a convenient and affordable way to filter tap water and remove contaminants like chlorine, sediment, and heavy metals. They are popular among people who want to improve the taste and quality of their drinking water without investing in a more complex filtration system.

Types

There are several different types of water filter pitchers available on the market, including

1. Basic pitchers. These pitchers use a simple activated carbon filter to remove contaminants and improve the taste of water. They are usually the most affordable option but may not be as effective at removing all contaminants.

2. Advanced pitchers. These pitchers use a multi-stage filtration process that may include activated carbon, ion exchange, and other technologies to remove a wider range of contaminants, including heavy metals, chlorine, and bacteria.

3. Alkaline pitchers. These pitchers use a special filter that adds minerals like calcium and magnesium to the water, increasing its alkalinity and potentially providing health benefits.

How they work

Water filter pitchers work by pouring tap water into the top of the pitcher. The water flows through the filter, where contaminants are trapped, and the clean water collects in the main reservoir. When the filter becomes clogged with contaminants, it should be replaced with a new one to maintain its effectiveness.

Some pitchers may also include a digital display or other features to indicate when the filter needs to be replaced.

Average prices

The average price of a water filter pitcher can vary depending on the type and features of the filter. Basic filter pitchers can cost as little as $20, while more advanced models with multiple filtration stages and additional features can cost upwards of $50 or more. 

Replacement filters should be changed regularly to maintain the filter’s effectiveness, and choosing a filter compatible with the pitcher model is essential.

Distillers

Distillers are a type of water filter that uses the process of distillation to purify water. They effectively remove contaminants from water, including bacteria, viruses, and minerals, making them a popular choice for people with specific water needs, such as those with medical conditions or in areas with poor water quality.

Types

There are different types of distillers available in the market, including:

• Countertop
• Portable
• Whole-house systems

Countertop and portable distillers are designed for individual use, while whole-house systems are installed at the point of entry to the house to provide purified water to all taps.

How they work

Distillers heat water to a boiling point, turning it into steam. The steam rises and passes through a condenser, which is cooled and returned to its liquid state, creating purified water. The contaminants are left behind in the boiling chamber and are discarded.

Average prices

The average price of a distiller can vary depending on the type and size of the unit. 

Countertop and portable distillers can cost anywhere from $100 to $500, while whole-house systems can cost upwards of $1,000 or more. 

Refrigerator Filters

Refrigerator filters are designed to purify water dispensed from a refrigerator’s built-in water dispenser and/or ice maker. These filters are typically installed within the refrigerator’s water system and work to remove contaminants such as sediment, chlorine, and other contaminants.

Types

There are different types of refrigerator filters that you can choose from the market, including:

1. Activated carbon filters
2. Reverse osmosis filters
3. Sediment filters.

How they work

Activated carbon filters are the most common type and work by trapping contaminants within the porous carbon filter. 

Reverse osmosis filters force water through a semi-permeable membrane to remove contaminants. 

Sediment filters work to remove large particles such as dirt, sand, and rust from the water.

Average prices

The average price of a refrigerator filter can range from $10 to $100 depending on the filter type and the refrigerator’s brand. 

Refrigerator filters typically need to be replaced every six months or after filtering a certain amount of water, as the manufacturer recommends.

Shower Water Filters

Shower water filters are designed to remove contaminants from the water that flows through a showerhead. These filters can help improve the quality of water that comes into contact with your skin and hair during a shower.

Types

There are several types of shower water filters that you can get on the market. These are: 

• Activated carbon filters
• KDF filters
• Vitamin C filters

How they work

Shower water filters typically attach to the showerhead or arm and are easy to install. They may also come with replaceable filter cartridges that need to be changed every few months or after filtering a certain amount of water, as the manufacturer recommends. 

• Activated carbon filters absorb chlorine and sediment from the water. 
• KDF filters use a combination of copper and zinc to remove contaminants.
• Vitamin C filters use ascorbic acid to neutralize chlorine and replenish your skin.

Average prices

The average price of a shower water filter ranges from $20 to $100, depending on the type of filter and brand.

Whole-house Water Filter System

Whole-house water filter systems are designed to purify water entering a home or building, providing clean, filtered water for all uses throughout the house. These systems can remove contaminants, chemicals, and sediment from the water supply, improving the water’s taste, smell, and quality.

The whole-house water filter systems can provide many benefits, including improved water quality for all uses throughout the house, reduced exposure to chemicals and contaminants in the water, and a longer lifespan for appliances that use water, such as dishwashers and washing machines. 

Additionally, filtered water can improve the taste and odor of drinking water, making it more enjoyable to drink.

Types

There are several types of whole-house water filter systems available, including:

1. Activated carbon filters
2. Reverse osmosis systems
3. UV disinfection systems. 

How they work

Whole-house water filter systems are installed at the point where the water supply enters the home, typically in the basement, utility closet, garage, or outside. This is why they are also commonly referred to as Point-Of-Entry filtration systems. The water passes through the filter system before it is distributed throughout the house. 

• Activated carbon filters work by adsorbing contaminants and chemicals from the water
• Reverse osmosis systems use a semi-permeable membrane to remove contaminants from the water. 
• UV disinfection systems use ultraviolet light to kill bacteria and other microorganisms in the water.

Average prices

The average price of a whole-house water filter system ranges from $500 to $5,000. It will also depend on the type of system, size of the home, and level of filtration needed. 

Note: It is essential to have a professional install a whole-house water filter system to ensure that it is properly installed and functioning correctly.

Popular Water Filtration Technologies

Each water filtration technology has unique features, benefits, and drawbacks. Hence, choosing the right one for your needs depends on various factors such as:

• the type of contaminants present in your water
• the level of purification required
• the budget available. 

In this section, we will provide an overview of these water filtration technologies to help you make an informed decision when selecting a water filter.

Carbon Filtration

Carbon filtration is a technology that uses activated carbon to remove contaminants from water. Activated carbon is a form of carbon treated with oxygen to make it porous, increasing its surface area and making it more effective at adsorbing contaminants.

How it works

When water flows through a carbon filter, the activated carbon adsorbs contaminants such as chlorine, volatile organic compounds (VOCs), pesticides, and herbicides. The carbon filter traps these contaminants within the filter media, allowing clean water to pass through.

What it removes

Carbon filters are effective at removing common water contaminants such as:

• Chlorine
• Chloramine
• volatile organic compounds. 

They can also improve water’s taste and odor by reducing contaminants contributing to unpleasant tastes and smells.

Advantages

• A simple and affordable method of water filtration
• It can be used in various applications, from countertop filters to whole-house filtration systems. 
• Effective at removing many common water contaminants
• It can improve the taste and odor of water. 
• Deemed safe and environmentally-friendly
• It can be easily disposed of or recycled.

Drawbacks

• May not be effective at removing all types of contaminants, such as minerals or heavy metals
• Increases maintenance and replacement cost as they become saturated over time
• Some carbon filters may not be able to handle high flow rates, leading to reduced water pressure.

Reverse Osmosis

Reverse osmosis (RO) is a water filtration process that forces water through a semi-permeable membrane. This membrane allows water molecules to pass through while blocking the passage of larger particles and contaminants.

How it works

The process works in these stages:

1. Pre-filtration. Water from the source is first passed through a pre-filter, which removes larger particles such as sediment, sand, and dirt. This step helps to protect the RO membrane from damage or clogging.
2. Reverse osmosis membrane. The pre-filtered water is pushed through the semipermeable RO membrane under high pressure. This forces the water molecules to separate from contaminants, which are then flushed away as wastewater.

The result is clean, purified water free from most contaminants, including bacteria, viruses, lead, chlorine, fluoride, and other harmful chemicals.

What it removes

RO systems are effective at removing a wide range of contaminants from water, including:

• Total dissolved solids (TDS)
• Bacteria and viruses
• Lead and other heavy metals
• Chlorine and chloramines
• Fluoride
• Pesticides and herbicides
• Pharmaceuticals and hormones
• Nitrates and nitrites

Advantages

RO systems offer several advantages over other types of water filtration systems:

• Effective at removing a wide range of contaminants
• Provides high-quality, great-tasting water
• Can be installed as a point-of-use (POU) or point-of-entry (POE) system
• Low maintenance if you are replacing your filters consistently
• Easy-to-replace filters and membrane
• Environmentally friendly, as they don’t require electricity or produce wastewater

Drawbacks

• Produce a significant amount of wastewater during the filtration process
• Slower than other types of filtration systems due to the pressure required to force water through the membrane.
• Removes beneficial minerals such as calcium and magnesium
• Requires professional installation

Ion Exchange

Ion Exchange is a water filtration process that removes dissolved minerals such as calcium, magnesium, and iron, contributing to water’s hardness. This method is commonly used for water softening, but it can also be used to remove other contaminants.

How it works

Ion exchange exchanges the ions of unwanted minerals with ions of other materials. It uses a resin that contains negatively charged ions that attract and hold onto positively charged ions. 

As the water flows through the resin, the unwanted ions are exchanged with ions of a more desirable substance, usually sodium or potassium. This process results in softer water that is free of hardness minerals.

What it removes

Ion exchange is effective in removing minerals that contribute to hardness in water, such as:

• Calcium
• Magnesium
• Iron

It can also remove heavy metals such as:

• Lead
• Copper
• Cadmium
• Nitrates
• Some radioactive elements

Advantages

• Effective in removing hardness minerals that cause scale buildup in pipes and appliances
• Improves the taste and clarity of the water
• A simple and reliable method that requires little maintenance.

Drawbacks

• Requires the use of salt to regenerate the resin. 
• Increases the sodium content in the water, a concern for those on a low-sodium diet or with hypertension. 
• Cannot get rid of other types of contaminants, such as bacteria, viruses, and chemicals
• Costly since resin needs to be replaced periodically

Distillation

Distillation is another popular water filtration technology that works by heating water to the boiling point and then collecting the steam, which is then condensed into liquid form. This process removes contaminants from the water, leaving it pure and free from harmful substances.

How it works

The distillation process involves boiling water in a chamber, which creates steam that rises and enters a condenser, where it is cooled and condensed back into a liquid. 

The condensed water is then collected in a separate container, leaving behind any contaminants that were removed during the process.

What it removes

Distillation is a highly effective water filtration technology that removes a wide range of contaminants from water, including:

• Bacteria
• Viruses
• Minerals (such as calcium and magnesium)
• Heavy metals (such as lead and mercury)
• Pesticides and herbicides
• Chlorine and other disinfectants
• Volatile organic compounds (VOCs)
• Nitrates and nitrites
• Fluoride

Advantages

• Effectively removes a wide range of contaminants from water
• Produces high-quality water that is safe to drink
• Can remove contaminants that are difficult to remove with other filtration methods

Drawbacks

• Slow and energy-intensive process, making it less efficient than some other filtration methods
• Requires regular maintenance to prevent mineral buildup and other issues
• Removes beneficial minerals from the water and harmful contaminants, making the water less healthy to drink in the long term.

UV Purification

UV purification is a water treatment process that uses ultraviolet light to kill or inactivate harmful microorganisms in water, such as bacteria, viruses, and parasites. UV light disrupts the DNA or RNA of these microorganisms, making them unable to reproduce and causing illness. 

This technology does not use chemicals, and the treated water is safe to drink immediately after the process. UV purification is commonly used in homes and industries such as food and beverage, pharmaceuticals, and healthcare.

How it works

UV purification uses ultraviolet light to kill or inactivate microorganisms in water. Water is exposed to UV light as it passes through a chamber containing a UV lamp. 

UV light penetrates the cell walls of microorganisms, damaging their DNA and preventing them from reproducing. This eliminates bacteria, viruses, and other harmful microorganisms from the water.

What it removes

UV purification is effective at removing:

• Bacteria
• Viruses
• Other microorganisms such as fungi, algae, and parasites. 

Advantages

• It does not require any chemicals or additives to treat the water
• A safe and environmentally-friendly option. 
• Effective at killing bacteria and viruses
• Does not produce any harmful byproducts or waste.

Drawbacks

• Not effective in removing other contaminants such as minerals, chemicals, or sediment.
• Increases energy costs because it requires a power source to operate
• May not be suitable for water sources with high levels of sediment or turbidity.
• It can become less effective in killing microorganisms if the UV lamp is not replaced regularly.

Chemical Injection

Chemical injection is a water treatment method that involves adding chemicals to the water supply to remove or neutralize contaminants. The specific chemicals used will depend on the type and concentration of contaminants in the water. 

For example, chlorine or chloramine may be used to disinfect the water and kill harmful bacteria, while soda ash or sodium hydroxide can be added to adjust the pH level of the water and remove heavy metals.

The chemical injection process is commonly used for industrial and municipal water treatment and in some residential applications.

How it works

Chemical injection involves adding specific chemicals to water to remove contaminants. The chemicals are injected into the water using a specialized pump and mixed thoroughly. As a result, the contaminants are either neutralized or transformed into a form that can be easily filtered out. The water is then filtered using various methods depending on the type of contaminants present. 

What it removes

The chemical injection can remove a wide range of contaminants from water, including:

• Bacteria
• Viruses
• Algae
• Organic compounds
• Minerals, such as iron and manganese.

Advantages

• Can effectively treat large volumes of water at a low cost. 
• A simple process that can be easily automated
• Requires minimal operator intervention. 
• Chemicals used in the process are generally safe and non-toxic.

Drawbacks

• May not be effective at removing specific types of contaminants, such as heavy metals or sediment. 
• Requires careful monitoring to ensure that the correct amount of chemicals are added to the water –  too little or too much can result in incomplete treatment or over-treatment.
• Improper disposal of chemicals may harm the environment

Ultrafiltration

Ultrafiltration (UF) is a water filtration technology that uses a membrane to remove suspended solids, bacteria, viruses, and other contaminants from water. It is a type of membrane filtration where a semipermeable membrane with very small pores separates the contaminants from the water. 

The pores in the membrane are typically 0.1 to 0.01 micrometers, which is much smaller than those in a typical microfiltration membrane. This allows ultrafiltration to remove much smaller particles than other filtration methods.

How it works

The process involves the following steps:

1. Pre-treatment. The water is pre-treated to remove large particles and sediment that can clog the ultrafiltration membrane.
2. Filtration. The water is forced through the ultrafiltration membrane, which acts like a sieve, trapping particles larger than the membrane’s pore size.
3. Backwashing. As the membrane becomes clogged with trapped particles, it must be cleaned. Backwashing involves reversing water flow through the membrane, dislodging the trapped particles, and flushing them out of the system.
4. Disinfection. To ensure the water is safe for consumption, it is disinfected with a chemical such as chlorine or exposed to UV light to kill any remaining microorganisms.
5. Post-treatment. The water is treated with a post-filter to remove any remaining contaminants and improve taste and odor.

What it removes

Ultrafiltration can effectively remove:

• Bacteria
• Viruses
• Sediment
• Rust
• Other larger organic molecules. 

Advantages

• A highly effective method of water filtration that produces high-quality water. 
• A relatively low-energy process
• Does not require the addition of chemicals.

Drawbacks

• May not be as effective at removing dissolved salts, minerals, or some chemicals.
• Expensive to install and maintain
• The membrane can become fouled or clogged over time, which can reduce the system’s efficiency.

Considerations To Select A Water Filter For Your Home

When choosing a water filter for your home, there are several important factors to consider. Here are some key considerations to help you select the right water filter for your home:

Well Water Vs. Municipal Water

The type of water supply you have will play a significant role in the kind of water filter you need. 

Well water typically has higher sediment levels, minerals, and other contaminants than municipal water, which often requires more advanced filtration methods such as reverse osmosis or distillation.

Municipal water, on the other hand, may require less intensive filtration but can still contain various contaminants that need to be addressed.

Water Contaminants

The specific contaminants in your water supply will also play a key role in selecting the right filter. It is essential to have your water tested to identify any harmful contaminants such as bacteria, viruses, lead, chlorine, or fluoride that may be present. 

This information can help you select a filter designed to effectively remove these contaminants and provide clean, safe drinking water.

Point Of Entry Vs. Point Of Use

Another important consideration is whether you need a Point of Entry (POE) or Point of Use (POU) filter. 

A POE filter is installed at the main water line entering your home and filters all the water that flows through it, while a POU filter is installed at a specific faucet or water dispenser and only filters the water that comes out of that outlet. 

POE filters are typically more expensive and require professional installation, but they offer comprehensive filtration for all water used in your home. 

On the other hand, POU filters are more affordable and can be easily installed by homeowners, but only provide filtration at specific points of use.

NSF Certifications

When selecting a water filter, it is essential to look for products certified by the National Sanitation Foundation (NSF). The NSF is an independent organization that tests and certifies water filtration products to ensure they meet specific health and safety standards. 

Here are some of the most common NSF certifications to take note of:

• NSF 42. For reducing aesthetic contaminants like taste and odor. It includes chlorine and chloramine removal
• NSF 53. For reducing specific health-related contaminants like lead and chlorine
• NSF 55. For UV filtration systems
• NSF 58. For reverse osmosis systems to remove various contaminants
• NSF 62. For water distillers
• NSF 177. For shower water filters
• NSF 244. For residential wastewater treatment systems
• NSF 350. For onsite residential water reuse systems.
• NSF 401. For reducing emerging contaminants like pharmaceuticals and pesticides.
• NSF P473. For reducing Per- and poly-fluoroalkyl substances (PFAS)

Your Budget

Finally, your budget is an important consideration when selecting a water filter. The cost of filters can vary widely depending on the type of filter, the level of filtration required, and the size of your home. 

Consider both the filter’s initial cost and ongoing maintenance costs to ensure you select an effective and affordable filter for your needs.

Final Thoughts

Choosing the right water filter for your home can be daunting, but it is crucial to consider several factors before deciding. 

Note that there are different types of water filters and filtration technologies. And you have to check each factor for consideration when selecting a water filter.

Ultimately, investing in a high-quality water filter can provide peace of mind knowing that you and your family are drinking safe and clean water. So, take the time to research and choose a water filter that meets your needs and preferences to ensure you have access to healthy and safe drinking water.

FAQs For Water Filtration Systems