Tap water is not the best option to drink as it can have various contaminants and pollutants injurious to human health. Drinking contaminated water can lead to various diseases; thus, everyone must use water filters for drinking purified waters. According to the Centers for Disease Control and Prevention, “About 7.2 million Americans get sick every year from diseases spread through water”. The majority of homes in the US have water filters installed to ensure contamination-free water. If you are facing drinking water contamination issues, you can use water filters.
This article is written to make the reader understand the basics of water filters and their types. By reading this guide, you can differentiate between different kinds of water filters and choose the one according to your needs as well.
What are Water Filters?
Water filters are the devices used to trap and block water contaminants, including sand, minerals, ions, salts, and some bacteria. These filters remove contaminants by using some substances to help in the filtration process. These substances include activated charcoal, carbon block, ion exchange resins or membranes (such as those made with cellulose), and reverse osmosis.
Types of water filters based on how they remove impurities. For example, by trapping them through gravity, attracting them onto an absorbent material such as granular activated carbon, or removing dissolved solids through membrane processes like reverse osmosis units. In this article, you will be provided with detailed information regarding these water filter types.
Types of Water Filters
Water filters are used to remove unwanted particles and impurities from water. You can remove sediments, hardness, taste, odor, and bacteria to get purified water. For better-tasting drinking water, you must use water filters. Here are the most common types of these filters used worldwide.
Reverse Osmosis (RO) Filters
To remove chemicals, minerals, salts, and other particles from drinking water, reverse osmosis filters are one of the best choices. A certain amount of pressure is used to reverse the natural flow of liquids through a semi-permeable membrane in reverse osmosis filters. Countertop reverse osmosis filters can remove up to 99% of TDS (total dissolved solids) from water; thus, they are largely used in homes.
A reverse osmosis filter can remove lead, radium, chloramines, nitrates/nitrites, bacteria, pesticides, herbicides, and much more. You have to change these filters once a year for better water quality, and they are also a little more expensive than comparing with other filters.
As the name suggests, sediment filters are designed to remove larger particles or sediments of sand, silt, and rust. People mostly use these filters as pre-filter for well water. A pre-filter helps protect the next stage of filtration from damage and extends the life of the actual filter. These filters can also filter smaller particles and contaminants along with coarse particles.
Sediment filters are mostly made up of sand or red brick, which is known as “grit.” So, if you have black sediments in your water, you should install a sediment filter to remove them.
Ion Exchange Filters
Ion exchange filters are used to remove heavy metals, microorganisms, and organic compounds from polluted water. Ion exchange resin beds are used in these filters, which have positively charged hydrogen ions (H+). So the contaminants are removed by attracting towards the resin bed in these filters. Besides this, ion exchange filters can also soften water and removes its hardness. Sodium ions are removed by these filters to soften water and are replaced by potassium or hydrogen ions.
Ultraviolet Disinfection (UV) filters
UV disinfection filters effectively remove microbial microorganisms such as bacteria, fungi, viruses, protozoan, cysts, etc. These filters kill 99.99% of harmful microorganisms in water. As clear from the name, UV light is used as a disinfectant in these filters to kill harmful microbes in water. Ultraviolet disinfection filters only remove harmful living entities from water and do not remove harmful chemicals, metals, and other ions. Thus, these filters are used combined with other water filters, mostly with reverse osmosis filters.
Activated Carbon (AC) Filters
Activated carbon filters are usually used to remove chlorine from drinking water. These filters also effectively remove heavy metals like lead and arsenic, volatile organic compounds (VOCs), pesticides, herbicides, and other contaminants. AC is porous, so that it can trap contaminants easily. These filters last for about 6 months to one year. There are two main types of these filters.
Granular Activated Carbon: These filters use powdered and loosely bound carbon to remove harmful substances from water. The surface area of these filters is small as compared to other filters, so it’s not effective against smaller contaminants. They are less expensive and filter water faster than other activated carbon filters. Moreover, they have a longer lifespan than activated carbon blocks.
Activated Carbon Blocks: Activated carbon blocks are made by grinding activated carbon and turning them into a powdered form. The powdered carbon is then mixed with a binder. It is then compressed into a solid block. These filters have more surface area and are more effective than granular activated carbon filters. Moreover, these filters have a lower flow rate, so they filter water slowly. These filters are more expensive, and you also need to replace them more frequently.
Distillation Water Filters
Water distillation is another process of removing harmful substances and contaminants from drinking water. Water distillers are used for this purpose. This water purification process fully eliminates bacteria and some harmful metals like lead, arsenic, nitrites, nitrates, pesticides, and herbicides.
Contaminated water is heated in distillers, and then purified water is condensed back into the water container, cooled down, and used for drinking. The contaminants are left behind in the container where they were boiled because they don’t evaporate as steam does. The distillation process requires a lot of energy to boil water. Moreover, it’s an expensive process as only a limited amount of water is distilled at once in the filter.
Ultra-filtration (UF) Water System
Ultra-filtration water filters use high pressure to force water through a very fine membrane. Larger particles in the water remain at one side of the membrane while the smaller particles are passed through the membrane with force. UF is more expensive to maintain and doesn’t use energy like reverse osmosis filters. UF resins are expensive to replace, and UF membranes are thinner than RO membranes, so they don’t last long and have a short lifespan.
Air Injection Iron Filters
Air injection iron filters are used to remove iron and manganese from water. A venture is used to introduce air into the existing pressure tank in this water filtration system. Oxygen is added to the waterline and then pushed through the pressure tank, which results in the oxidation of iron and manganese. These filters are also used to remove hydrogen sulfide but are unsuitable for removing higher iron levels in the water.
Chemical Injection Iron Filter
In a chemical injection iron filter, chlorine is used to remove bacteria, iron, and hydrogen sulfide from well water. A chemical feed pump in this system injects chlorine into the water. Chlorine reacts with iron and form rust. Once rust is formed, sediments filters are used to remove it. Thus, a chemical injection iron filter collaborates with other water filters to give purified water.
Ceramic Water Filters
Ceramic water filters are one of the oldest filters used to clean water. Although these filters are less common these days, they are effective and have many benefits. Mostly these water filters don’t use any electricity or chemical to purify water. Ceramic filters have tiny pores to trap bacteria and other sediments from the water.
Ceramic filters with carbon are common and improve the filtration process of water. The best thing about ceramic filters is that they are less expensive to maintain, and the initial installation cost is also considerably low. You must scrub and clean them regularly to increase their life span.
Water Filters Suitable For Home Installation
Various options are available to opt for home water filters. You need to pick the suitable one for your home wisely. Broadly, these water filters are categorized into two types. One is the whole house filter which is installed at the point of entry of water in the house. These filters are used to filter water at its source immediately after its entry into the house. The second type of water filters is called point-of-use water filters, which are used to filter tap water just before its use, just like a faucet-connected filter.
Here are the details of the most common and functional home-use water filters.
Whole House Water Filters
Whole house filters are also known as point-of-entry (POE) systems. These filters clean water immediately after its entry into the house. People prefer to install these filters in the basement. The best thing about this water filtration system is that you don’t need to install a separate filter system for each water outlet.
Whole house filters are more expensive and are also more difficult to install than other filters. If your water supply isn’t of good quality, then these filters are the best options you can opt for.
Inline Water Filters
Inline water filters are installed under the sink or inline with water pipes. Inline water filters are used as secondary water filters. These filters are most commonly used to purify the cold water line of your refrigerator and ice maker.
Under Sink Water Filters
Under sink water filters are a type of inline water filter, but they are used in kitchens. As the name suggests, these filters are installed under the sink. After installing them under the sink, you must attach a faucet diverter valve or replace an existing one with this filter.
These filters are the best option if your concern is only purified water for drinking. Moreover, they are also easier to install than whole house water filters.
Countertop Water Filters
Countertop water filters are installed on kitchen counters. These filters are used to get contamination-free water for drinking, cooking, and other kitchen tasks. Countertop water filters fall under the category of point-of-use water filters.
Countertop water filters are usually ceramic, carbon block, or reverse osmosis systems.
Water Filter Pitcher
Water filter pitchers are also point-of-use water filters. You have to fill these filters with water and then drink from them. These filters have activated carbon to filter your tap water. Water filter pitchers are good for removing fluoride from drinking water.
The alkaline filter is a popular type of water filter pitcher. It is used to neutralize the pH of the water and make it contamination-free. It is said that pH-neutral water offers various health benefits.
The drawback of these filters is that you need to refill them more frequently. Besides this, you need to replace them more often than countertop water filters. Lastly, these filters may not be very effective in removing heavy metals from water but are still good choices to clean your drinking water.
As the name indicates, showerhead filters are installed on showerheads. They filter the water as a point-of-use filter. These filters are not only easy to install but can also remove various impurities like chlorine, heavy metals, pesticides, etc. If you have to improve the water quality you wash in, these filters are the best options you have. These filters have a drawback as you have to install them in every bathroom. So, considering this drawback, whole house filters are better options to choose for your home.
As the water quality is deteriorating daily, water filters are becoming an essential need for every house. I have provided the details of the most common water filter types and their important features in this guide. I hope you find it helpful and get the best water filter per your needs.