Before we jump into the basics of home water filtration systems in it might help to get started with a bit of history. The Clean Water Act of 1972 was the first bill of its kind. The legislation introduced federal regulation around water supply pollution that covered everything from lakes and streams to municipal water systems. The bill was the first effective piece of legislation of its kind. It regulated the level of pollutants in your drinking water on a national level. This was huge. At this time in our nation’s history water contamination was something that was only managed on a state-by-state basis.

Additional amendments to the Clean Water Act in 1977, 1987 and 2018 tried to help mitigate the impact of floodwaters, as hurricanes began to ravage the coastline. The legislation worked to achieve three primary goals:

1. All U.S. water must be fishable/swimmable by 1983
2. Zero water pollution by 1985
3. Regulated levels of toxic pollutants in drinking water  

But here’s the kicker — here’s why knowing what’s in your drinking water REALLY matters. None of the above goals listed have been achieved. Nearly 70 percent of lakes, ponds, and reservoirs plus 90 percent of coastlines and surveyed ocean water still violate those standards to this day. 

And while cities are federally-mandated to treat your water with chemical disinfectants to kill germs and bacteria, that treated water is still damaging to your skin, hair, and your overall health. Not to mention that water treated with chemicals like chlorine typically have a bitter taste and sour odor. 

But at least the water is clean and healthy, right? Well, unfortunately, that’s not true either. Water treated by local utilities works to meet guidelines, but still contains trace amounts of contaminants like lead, pesticides, arsenic, and even nuclear waste. Sometimes the levels of these harmful contaminants are low, but often they are not. Often these toxins are found to be above federal guidelines, but with little recourse from state or local governments your water remains contaminated.     

So it doesn’t matter what regulation exists, you could still be drinking contaminants that are harmful to your health. 

Okay, time to take off the super scary hazmat suit, turn our James Earl Jones voice box off, and lighten the tone a bit. We swear, it’s not all doom and gloom.

Thankfully, regardless of what regulations exist, how the city treats your water, or what toxins are found in your neighborhood, you have the power to do something about it. Aside from mailing your local representative, and instead of purchasing hundreds or thousands of plastic bottles, you can invest in a home water filter.

That’s it, done and done. Once that decision has been made it’s really all downhill. So, to get you started, here’s our jargon-free explanation of how each filtration technology works, so you can make the best decision for your home, and your family.  

I. Different Types of Home Water Filters

There are many types of home water filters on the market, yet unfortunately, most companies out there make it really difficult to understand what the difference is between each system, and why you should care. They’ll tell you where they go in your home, and how much they cost, but they aren't clear about what they actually filter and they use a hundred Latin terms to explain how they work.

We aren’t about that. So, here’s a clear, jargon-free list of the different types of filters and filtration technologies that exist on the market today. 

The Stuff on the Inside: Let’s Start with the Water Filter “Media” 

When you read about water filter "media" just know that this is a fancy term for the stuff inside of each water filter cartridge. Most filtration devices are sold with hard plastic cartridges, and you may find yourself wondering, “So, what is inside of these filter thingys?”

The following list should help answer that question. Here are the main ones you need to know, and we’ve listed them in the order they are typically laid out in a home water filter system:

1. Mechanical or Sediment Filtration 

With mechanical or sediment filtration, the filter will use some sort of medium like cloth or sand to trap larger particles in your water. Think of this filtration stage as a heavy-duty coffee filter. You’ll usually see this within the first stage/pre-filter in all filtration systems you encounter.

2. Carbon

Carbon is the most common media for any home water filter. It acts like a magnet to attract toxins in your water. Likely, any type of water filter you find will have at least one stage of carbon.

You will see many titles and names for carbon-based medias used in water filters. Coconut shell carbon, carbon blocks, and granular activated carbon are all examples of carbon media types, but for our purposes just know that as a filter media, carbon is essentially charcoal treated with oxygen.

This process opens up millions of tiny pores that can catch and trap contaminants. This is where our magnet metaphor comes into play. The carbon pulls in the contaminant and traps it within the pores.

Carbon is great at removing chlorine and other disinfectant byproducts, so the primary use for a carbon media is to clean up the taste and smell of your water.

Carbon may be a basic media type found in almost all filters, but don’t get us wrong, a simple carbon filter can take your dirty tap water a long way down the road towards toxin-free water. 

3. Ion Exchange Resins

This category is likely the most “sciency” of all media types. Ion exchange resins are small beads that are chemically engineered to bind to and replace specific elements found in your water.

Though resins are quite technical in design, the concept is fairly straightforward to grasp. Water passes over a resin bead, then that bead is embedded with a positively or negatively charged ion and therefore attracts and replaces the opposite ion that you want to remove.

Many home water filters utilize a variety of resins to really pinpoint the filtration process. Resins can remove specific nuance chemicals such as heavy metals, PFAs, and other toxins, or they can be utilized to soften water by removing calcium and magnesium.  

The water softening process is a very common use case for ion exchange resins, and offers a good example of how ion exchange works.

In a water softening system, resins embedded with negative sodium ions are used to bind to positively charged calcium and magnesium ions. Once they are bound, sodium gets displaced into the water, and calcium and magnesium are removed. So the water will typically end up a little higher in sodium, but much less “hard” (i.e. full of calcium and magnesium), which can cause scale and build up.

We will get further into water softeners below but wanted to use water softening as an example of how Ion exchange can work in practice. 

4. Reverse Osmosis Membrane

Though many systems are termed ‘RO Filters’, the process of reverse osmosis is actually another media type that is typically used in combination with all other media types listed here. Using the force of water pressure, water is pushed through a very compact semi-permeable membrane. Because the RO membrane is so tightly compact, the contaminants become trapped. An RO filter can trap everything from fluoride, lead, VOCs, pesticides, heavy metals, and more, leaving everything that comes out on the other side completely pure and clean.

One question that often comes up is what happens to all of those contaminants that get trapped? Well, that is a good question and also one of the few downsides of an RO-based filter.

The trapped toxins are rejected as wastewater. So, pure filter water comes out on one side and dirty contaminated water is discarded out the other.

As mentioned, RO membranes are almost always coupled with all of the above media types. They work together to cut down on the amount of wasted water and increase the longevity of your RO membrane. 

5. Remineralization 

This media filter is typically added onto the back end of a reverse osmosis filter. Since reverse osmosis leaves your water completely pure, with little to be found outside of hydrogen and oxygen, the water can be lacking necessary minerals such as calcium and magnesium. These minerals are necessary for your health, they help your water taste good, and they help raise the pH to an alkaline level.

The two most common remineralization media are calcite (adds calcium) and corosex (adds magnesium). In our opinion, a remineralization stage is essential if you decide to go with a reverse osmosis filter option. 

Now, Let’s Take a Look at the Different Types of Home Water Filter Hardware

This is always the part where people get stuck — and we get it. There are seemingly hundreds of different ways to filter your drinking water. We are here to break it down, filter by filter, starting with the least expensive and lightweight filter options. Then, we will cover the more in-depth heavy-duty filtration options as we move down the list.

Pitcher Filters

Pitcher filters are one of the most popular filter types out there due to their ease of use, low price point, and versatility. It is handheld, much like a jug of milk, and lives in your fridge. It typically uses activated carbon to improve the taste of your water. That’s why you’ll sometimes see little black bits in your filtered water. It’s not pepper — it’s just carbon.

So how does it work?

It acts like a magnet to grab the contaminants like zinc, chlorine (from the city treatment process), and sulfides that can make your water have a metallic taste and smell. Pitcher filters don’t filter out all contaminants, but it’s a good starting place if you’re just trying to filter out the basics and improve the taste.

Pitchers are the least effective at treating a wide range of toxins, but they do have the luxury of being fairly low in cost.

Faucet Filters

The faucet filter is another popular water filtration option and will get the job done if you are simply looking to improve the taste of your water.

This type of filter snaps directly to your kitchen faucet, acting as an extension of your tap and filtering as it pours. These are fast, easy, and convenient to install. A faucet filter is usually carbon-based as well, and often utilizes a blend of resins to target specific toxins.

Faucet filters remove a list of contaminants ranging from Volatile Organic Compounds (VOCs), asbestos, chlorine, and more. But if you want something that expands that list to remove harmful chemicals like lead, pesticides, and heavy metals from your war, then you’ll want to look into the under-sink filter options outlined below.

Fridge Filters

Fridge water filters are the ones that commonly come with the refrigerator you purchase. Like pitcher and faucet filters, fridge filters are also carbon-based. They're great at reducing chlorine and improving taste but aren’t going to target some of the other major contaminants found in tap water.

A quick side note: always remember to change your fridge filter. Most filters, when expired, can be worse than just drinking water straight from the tap, and fridge filters are notorious for sitting in a fridge for years unnoticed. 

Countertop Filters

This type of water filter actually has the most diversity in the market. While most countertop water filters do use carbon filtration technology, they also combine a myriad of different resins and technologies that vary based on the specific product. 

Types of Countertop Filters:

• Plug-in countertop filters — There are a few countertop water filters that plug directly into the wall as an appliance would, using a pump system to increase water flow. 
• Gravity filters — these rest on your countertop and let the water naturally flow from a top filter basin to a bottom holding tank. Gravity based countertop filters can be thought of as large pitcher filters and are the kind you typically see used at weddings and large gatherings where no faucet or electricity is nearby. 

Countertop filters range in size, shape, and function, so it is difficult to say exactly what they can and cannot filter without discussing the specific make and model. Generally though, a countertop option is great at removing the common irritants like chlorine and fluoride, and higher-end models do a good job with some of the more difficult toxins like lead, pesticides, and heavy metals. 

In summary, countertop filters are super portable, easy to install, and come in a lot of shapes and sizes. They are often the best option for renters who don’t feel comfortable installing something more permanent. Countertop units tend to work better than pitchers, faucet-mounted filters, and fridge filters at removing a long list of contaminants. But, like everything in water filtration, the quality of the product really determines the effectiveness. 

Under Sink Filters

Under sink water filters often look like science experiments. They are intimidating, with hoses and cartridges wildly flailing around in different directions. We aren’t really sure why they all look so confusing, but at the end of the day you should know that an under sink option is likely the most complete and thorough way to filter your tap water. If you are looking for a solution that removes the most toxins, then you should start here. 

A couple of quick things to cover before we jump into the two main types of under sink systems and how they work.

First, under sink water filters are typically installed into a separate spigot that dispenses clean drinking water. The spigot installs right into your sink basin or countertop. I’m sure you've seen them and/or used them before.

Secondly, installation can be tricky. We highly recommend having a professional plumber install your under sink system. While the average Joe CAN do it, there are several problems that can arise when tapping into existing plumbing, and you don’t want to get caught searching Yelp for a local plumber while your kitchen is flooding. Do yourself a favor and leave it to the pros, especially if you decide to go with a Reverse Osmosis unit.

Lastly, all filters need to be replaced regularly. Under sink water filters are no exception, and replacement timelines typically range from 6 months to 18 months. Oftentimes under sink filter cartridges are more difficult to replace then the above filter systems. We don’t know why that is, and here at Cloud we are looking to fix it with easy, do-it-yourself replacements.

More on that below, but first a look at the two main types of under sink home water filters: 

Reverse Osmosis Water System:

Well, we are biased because we focus on RO systems, but in our humble opinion an under sink reverse osmosis system is the most robust and high-quality filter on the market. If you are looking for a filter that can remove nearly all toxins, while also delivering perfectly clean, alkaline water, then this is the way to go. The pre-filters also have the added benefit of extending the lifetime of the RO membrane so that it only needs replacing once every 1-2 years.

The RO membrane filters down to such small levels, that it catches 99% of the toxins in your water including fluoride, lead, bacteria, pesticides, herbicides, VOCs, pharmaceuticals, nuclear particles, PFAs, and any remaining chlorine that the carbon didn’t grab. If you want your water completely purified, this is the way to go. 

After the water passes through the RO it will typically travel through a post filter. The post filter is often a combination of carbon and resins that are meant to ‘polish’ your water, a fancy term meaning make it taste better, and re-introduce essential minerals. We discussed re-mineralization above so we won’t dive too deep here. Just know that it is important when researching reverse osmosis home water filters to double-check that this final remineralization step is included. It isn’t always, and in our opinion, it is essential when you invest in a high-end filtration unit like an RO. 

Lastly, we should mention the installation. Because RO units typically create wastewater, they are also the most difficult to install. We recommend a professional installation. Nothing in life is ever easy, is it? If you want the top of the line in filtration technology you have to work for it a bit with the install.

Installation requires the user to:

1. Tap into your water line and connect into the system
2. Drill into your waste line for disposal of the polluted water that has been filtered out
3. Mount a water spigot in your sink or counter if you don’t have one placed already. 

Non-Reverse Osmosis Under Sink Systems:

These types of home water filters are installed under the sink as well. They lean heavily on activated carbon and filter your water in stages — some under sink filters are as little as two stages and others can be as many as six. They are similar in design to the above mentioned RO units and are just missing the reverse osmosis membrane as a filter stage. 

Depending on the number of stages, the water will weave its way from sediment filter to carbon, to resin, and back to carbon again, until the water finally reaches your glass.

These multi-stage under sink home water filters do a really good job, and can often be significantly less expensive than an RO unit. They don’t typically work quite as well at removing all contaminants, but there is always that trade-off with price.

Whole Home Water Filters

Imagine that multi-stage under sink filter we mentioned, but larger, and installed at the point of source. "Point of source" means they are installed before any water reaches your home, in-between the water main on the street and the inlet to your home. The water main coming into your property is connected directly into this mega filter, and then clean, filtered water is passed on to all the different water sources in your home. Kitchen sink, showers, baths, bathroom sinks — everything is filtered. That is really the selling point for a whole home filter: you get full coverage.

Whole-home systems use many different types of filtration techniques and media to filter anything from sediment to contaminants out of your water. Like the under sink setup, each system is different so you need to make sure the product is exactly what you need for your geography. They’re highly configurable too, so you can customize them to fit your home, and your family's needs. These units are significantly more expensive to purchase, and to install. Something worth considering as you start in on your research.

Whole Home Softeners

Whole-home water softeners are a category unto themselves. Most people who experience hard water know how much of a problem it can be. From build-up in faucets and pipes to orange/rust-colored stains on the tub or sink to stinky laundry — hard water is a host unto itself.

Using the ion exchange process discussed above, whole house water softeners remove calcium and magnesium particles by swapping them out for sodium ions. The effect is silky smooth water, and no more problem-causing build-up and deposits.

Like whole home water filters, softeners are installed at the point of source, where the water feeds into your house. This is typically inside your garage or on the side of your house. 

These systems often come with a corresponding water filter to make sure your water is both clean and soft. But because of the high sodium content in softened water, you may also need to install a separate drinking water system at the point of use, such as a countertop or under-sink unit.

While whole home softeners are the biggest and often the most expensive devices on the market, water softeners can become a necessity for homes with serious hard water problems.

II. What About All the Good Minerals in My Tap Water?

The type of filter you purchase totally depends on what you want filtered out, and conversely what you want to leave in. Now, you may be saying to yourself, “What do you mean leave stuff in? I just want pure clean water.” Unfortunately there is such a thing as overly-filtered water.

You see, when we talk about natural spring water, essentially the really good stuff that comes straight from mother earth, we are talking about water that has trace amounts of essential minerals your body needs. Calcium, potassium, magnesium, sodium, are all healthy, necessary elements in drinking water. Not only do they help your body absorb vitamins and minerals, but they also help keep you hydrated.

An added benefit is that water including minerals is typically more palatable. Not a noticeable “taste”, but mineral water has been described as sweeter, with an added silky smooth texture.

Think of Fiji or Smartwater for example. Ever notice that those waters taste a bit smoother and leave you feeling more hydrated? That is due to the trace mineral content. The minerals bump up the pH making the water more elegant, smooth, and hydrating. 

In nature, minerals are picked up as water flows through streams, rivers, and even underground aquifers. As the water flows over rocks and sand it picks up minerals along the way.

Ultrafiltered water, such as reverse osmosis water and distilled water, strips these natural mineral deposits, leaving you with plain old H2O. In order to get those minerals back, filtered water is often treated with a “post-filter” or “remineralization stage”.

Sometimes filtration companies will have fancy, proprietary names for this post-filtrations stage, but for our purposes what you really need to know is that as the water passes through this final stage it reintroduces the minerals you want and need.

The remineralization process is typically very simple. The post-filter works like a natural stream picking up minerals as the water makes contact with the media. Typically two compounds, calcite and corosex, are used to add calcium and magnesium, but other minerals may be added to the media as well such as potassium, sodium, and bicarbonate. 

IV. Understanding Alkaline Water

Alkaline/alkalinity is the latest trend in clean, filtered water. But not many people know just what it means, or what to make of it for that matter. Let’s start with the basics.

Alkalinity refers to the pH of water. pH is measured on a scale that ranges from 0-14, with 0 being very “acidic” (think battery acid), and 14 being very “basic” (think bleach). Pure water (H2O) falls smack dab in the middle at a pH of 7. So, when we say alkaline water, we are talking about water that has been treated, usually through the process of remineralization discussed above, to fall just above a pH of 7. Alkaline water has a pH range that typically falls in the 7.5-10 range. 

Though the science is still widely debated, alkaline water is said to have many health benefits. The heightened pH acts as a balancing mechanism for the acid in your water. This also helps to neutralize the acid in your body.

Many claims are made as to the health effects of alkaline water, and while the research is still hotly debated, proponents claim that alkaline water supports your immune system function, enhances hydration, and has detoxifying properties. 

In other posts we will dive deeper and cover all the health claims methods used to make water more alkaline, as well as the cases for those who are anti-alkaline, but for now, we will just leave you with the basics. 

III. How do I know which water filter is the real deal?

The best way to tell is by looking for certifications like NSF, WQA, and IAPMO. 

The NSF is a nonprofit that was founded in 1944 to independently test and certify products for consumers that work to improve global human health. When you see an NSF mark on a product, be sure to ask the company for their NSF documentation, or check the NSF website for the certification details. The NSF database will show you which contaminants the filter will actually reduce from your water, to what degree, and the margin of error. NSF is the most widely attributed certification for the filtration space. 

The WQA — or Water Quality Association — is a US-based nonprofit that works to formally represent and identify official water filtration companies within the industry. Directly from the WQA, they are “a resource and information source, a voice for the industry, an educator of professionals, and laboratory for product testing.”

IAPMO — or the International Association of Plumbing and Mechanical Officials — was founded in 1926. They work to create formal standards around water quality, as well as to test and certify the legitimacy of a water filtration product. 

Additionally, if you’re a researcher who spends a great deal of time weighing the pros and cons of a product before investing any money into it, you know that there’s one more tried and true way to get some perspective. Be sure to check for reviews.

IV. Drinking Filtered Water

Okay, that’s all for now. There is a lot of information in this guide, but it's a good knowledge base to send you off into the scary world of water filtration with the tools you need to separate fact from fiction. 

The benefits of drinking clean filtered water are endless, from the ecological consequences of plastic pollution to the health benefits of drinking an abundance of clean water. While there are countless studies that have shown the very real mental and physical health consequences of drinking contaminated water, we won’t harp on that too much here.

At the end of the day, it’s not the tech that’s going to convince you to invest in a quality water system, or the reviews, or the media for that matter. It’s knowing that you and your family are drinking clean, healthy, filtered water. 

Alright, bye for now.