How Do Water Filtration Systems Work?

Water filtration system

Water filters are more common these days than ever before. More people have water filters somewhere in their homes and grocery stores are now installing heavy-duty filters so that customers can get clean water by the gallon. It seems like more people want cleaner water then what they get from the faucet, and are turning to new filtration services to get it.

However, not all filtration is created equal. Different filters remove different materials while leaving others, and some filters can’t catch smaller particles. For those of us who are sensitive to bad water or the chemicals in that water, a good filter is a necessity and not a luxury.

Here, we’ll go over what goes into a filter system. This includes discussing why people want filters in the first place, the kinds of materials used in filters, where people install their filters, and how a typical water filter system works.


Why Use a Water Filtration System?

The fact is that while municipal water is commonly treated before it gets to your home, it isn’t 100% clean. It would cost cities so much money to treat water perfectly that water prices would skyrocket. That’s why most cities make water clean and safe to drink, and leave more detailed water treatment and filtration to the homeowner’s discretion.

Since you are reading this, we assume that you are interested in having cleaner water. The reasons you might want cleaner water come from several problem areas with public water service:

  1. Public water often tastes bad. As water moves through piping, collecting minerals and other particles from surrounding metals, it can collect a less-than appetizing taste that only filtration can remove.
  2. Public water can include unwanted minerals or chemicals. Even the cleanest water from a public source can collect trace minerals and chemicals from the surrounding environment. Some of these minerals are helpful (Manganese, Calcium, and Sodium being some of the helpful ones), while others like Arsenic and Lead are not. Water is also often treated with chemicals like Fluoride that, while not unhealthy in and of themselves, might be something that homeowners don’t want as part of their in-house water supply.
  3. Public water can become contaminated. Water mains break during storms or during public construction, introducing bacteria and other problematic particulates to a water supply. When this happens, cities typically issue a boil order to keep residents safe, but the word for a boil order may not reach everyone before they drink contaminated water. Also, water from a boil order can ruin appliances like refrigerators with built-in water filters or ice makes.

Bad taste, harmful chemicals, and contamination can all come from what the CDC calls “volatile organic compounds.” These compounds can easily make their way into any municipal water system either by accident or just as part of the process of transporting the water to your home.

With these three problems in mind, you can see how a water filtration system makes sense.


Types of Water Filtration

There are three common ways to remove chemicals and particles from water reliably.

water filtration
  1. Activated charcoal filters allow water to pass through while pulling out particles. Charcoal filters are what you commonly see in on-point filters attached to the faucet, or in the water pitchers that include built-in filters. Charcoal works well in removing chemicals like chlorine that cause water to taste bad.
  2. Reverse Osmosis filters use a permeable membrane to remove particulates from water. As water passes through the membrane, minerals like Lead and Mercury are removed.
  3. Steam Distillation filtering boils water to a certain temperature so that it turns into gas, leaving minerals and particles behind.

The first two filter types are very common, and are often combined in a single solution. Steam distillation is used more often in commercial settings rather than residential.

There are additional filtration technologies emerging to combat impure water. Tools like UV and infrared lights are helping filter manufacturers eliminate tougher impurities due to bacteria, mold, and other biological materials. New ion filters use electrical charges to remove particles while softening water at the same time. While these filters are becoming more common, the above three are still the most recognizable in today’s water filter systems.

A Common Filtration System

Your typical filter system will include multiple layers of filters to ensure clean water.  However, the kind of filtration used will determine how it works.

First, water enters the filter. Depending on the type of filter and its location, this can be directly from the faucet, dripped through a pitcher, or pushed through a main water line.

As water enters the filter the associated water pressure from its point of entry pushes it through the filtering medium. In the case of charcoal, the water is pushed through the pores of the charcoal so that the minerals and contaminants are left behind. For a reverse osmosis filter, the water is forced through the pores of the membrane to the same effect.

Once the water passes through the filtering medium, there can be further treatments to purify the water. For example, after water passes through the membrane or charcoal filter, you might find a built-in UV light to kill fungi and bacteria. Or, you might find another, finer filter collecting particles missed in the first pass

Sometimes, you might even see combined filter systems to maximize filtration and purity. For example, a charcoal filter might start the process by removing minerals and chemicals before the water moves to a reverse osmosis membrane for a finer filtering.

In either case, water will be served either directly or to a reservoir for future use.

Where are Filtration Systems Typically Installed?

Filters are installed nearly anywhere a water supply is. There are, however, a few common areas you will see a filtration system:

water filtration systems
  • Water pitchers with built-in filters are common in most homes. These serve as a great, quick, and easy way to get filtered water without having to invest a lot of money. Obviously, the uses of such filtration are limited, but they get the job done.
  • Water filters attached to a faucet provide more consistent filtration without having to have a separate pitcher for drinking water. With a faucet filter, you can get filtered water immediately without having to fill a pitcher.
  • Under-the-sink units accomplish much of the same filtration needs as filters attached to the faucet, expanded across all the water used in that kitchen. An under sink filter can include much more in-depth filtration and water filtering as well as water softening for your dishwasher.
  • Whole-home water filtration systems typically use heavy-duty and multi-layered filtration methods, and connect to a reservoir so that you have fresh and filtered water throughout your home.

Depending on where you filter is, you might find you have a different style of filter. For example, pitcher and faucet filters rarely have reverse osmosis membranes, opting instead for activated charcoal filters. A whole-house filter, however, will typically included a multi-stage filter and a reservoir to serve the needs of the entire home.

How Can You Save Water?

Water filtration systems work by running water through a porous material to remove chemicals, biological agents, and unwanted minerals. Whether it is charcoal, membranes, or UV lights, filters can typically kill anything in your water. This is great news for those of us who just want to trust our water will taste good and not contain harmful chemicals.

However, make sure to determine what filter is right for you. Reverse osmosis filters, for example, can remove minerals that are actually helpful to us. Consult with your local plumber to determine what kind of water purification you want, and what kind of filtration system will be right for you and your needs.

Consult with Your Plumber

Modern, water saving fixtures don’t install themselves. If you are looking to put in new, water-saving appliances, then call your plumber to see what they have available. Also, consult with them about any of your sink or shower fixtures to see if they need upgrading or replacing. Don’t let leaking hardware wastewater, and don’t trust older equipment to stand up to modern water-saving standards without at least a bit of repair, if not replacement.

If you make some of these basic changes, however, you will help with global efforts to save a crucial natural resource, and you could end up saving money in the long run.


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