How to Filter Water: 2022 Ultimate Guide by Experts

The average drinking water source contains traces of more than 200 contaminants. It’s understandable if you’re concerned about the quality of the water you’re exposed to.

Luckily, there are plenty of ways to filter your water and make it safe to drink.

In this guide, I’ll be discussing the ins and outs of filtering your water, including the best methods, the benefits of filtration, and much more.

📤 How to Filter Water at Home

You might think that your home’s drinking water is relatively clean, but it could still be a whole lot cleaner. While water treatment facilities must legally remove certain contaminants down to trace levels, that doesn’t mean your water is completely free from impurities.

You might want to filter your water at home if you have health concerns about some of the contaminants you’re drinking, or if water poses an aesthetic problem (such as limescale).

Filtering tap water at home

To filter your water at home, follow these steps:

1) Find Out What Contaminants are in Your Water

You won’t get very far if you don’t already know what your water contains.

Before you can choose a filter, it makes sense that you need to first know what you want to remove.

It’s best not to guess by taste, here. A lot of contaminants are tasteless – and odorless, and pretty much invisible, for that matter. The only way to detect what your water contains is to do a test.

There are two options here: take a beginner-friendly at-home test, or upgrade to beast mode and test your water using a certified laboratory.

At-home test kits are easy to use and indicate whether your water contains the most common contaminants, but they’re nowhere near as accurate as laboratory testing. But, as you’d expect, lab testing is about five times the cost of at-home testing.

I recommend testing for chlorine, lead, pesticides and herbicides, water hardness, nitrates/nitrites, and copper, at the very least. If you own a well, you should also test for bacteria.

If you don’t want to spend any money on testing at all (and you get municipal water), take a look at your local Water Quality Report or Consumer Confidence Report, which breaks down the trace contaminants in your water. You can find your local Water Quality Report here.

water testing with tap score

2) Select Filter Method

Armed with your test result data or CCR information from step 1, you can now venture into the unknown: choosing a filtration system.

But wait! First, you need to decide on a filter method, and there are several to choose from.

Not all filters produce the same results. Some of the most popular filtration methods are:

Learn more about the different types of water filters and filtration methods in this post.

3) Select Application

After deciding on a filter method, you’ll need to choose a filter application.

It sounds confusing, but this is essentially where you’d prefer to install the filter or the situation in which the filter will be used. In some cases, this might mean zero installation – for instance, a pitcher filter just needs assembling before it can be used.

The common at-home filter applications are:

Consider the pros and cons of each type of filter application before you make a purchase.

Check out our shortlist of the overall best water filter systems in 2022.

4) Install & Prepare the System

Once you’ve purchased a system, the hard work isn’t quite over.

You’ll need to install the system (or pay for somebody to do it if the installation process sounds scary).

Installation may involve cutting into your waterline, or may be as simple as unboxing and assembling the components.

To prepare a filtered water system, you may need to flush the filter before getting started.

5) Perform Maintenance & Change Filter Cartridges

After installing the system, you can enjoy the perks of having your own water filter to improve your water quality. But don’t forget system maintenance!

In cartridge-based systems, you’ll need to replace the water filters as outlined by the manufacturer. In media filters, you should replace the media as necessary.

Some filters also need to regenerate or backwash. You can program regeneration or backwashing in advance.

🏕️ How to Filter Water in the Backcountry

Most backcountry water sources in developed countries can make us sick to drink. This water can contain contaminants like bacteria, which should be filtered out before you drink it.

Whether you’re hiking or backpacking in the backcountry or living in a developing country for the indefinite future, using a filter to make sure your water is clean and safe is essential.

filtering water in the backcountry

Portable Water Filters

Portable water filters are the easiest solution for accessing clean, filtered water away from home.

There are several styles of portable water filtration systems, including straw filters, filtered water bottles, gravity filters, and pump filters.

Most filters use a cartridge design, but UV is another increasingly popular choice for portable filtration.

You can learn more about the best portable water filters here.

Boiling

Boiling water is one of the simplest ways to kill germs in water. It’s fast, too – boiling your water for 3 minutes is usually enough to kill off any nasty germs.

You can boil water in any setting, as long as you have a heat source, a pan, and a storage container. It’s best to boil water in batches and drink it as soon as it’s cooled if you’re out in the wilderness, which will prevent recontamination.

Note that you can’t boil your water to remove contaminants – it can only kill live organisms like bacteria and viruses.

Impurities like heavy metals and chemicals aren’t technically “alive” in the first place, and they have very high boiling points, so heating them up will usually do nothing.

Related: My guide to boil water notices & advisories

Chemical Disinfection

Chemical disinfection at home involves using an advanced piece of technology, like a chemical injection system. You don’t get that sort of luxury in the wilderness (it’d be pretty heavy to carry around, for one).

The easiest way to disinfect your water on the go is by using chemical disinfection tablets or drops.

These tablets, often sold as water purification tablets, take up to 30 minutes to kill waterborne germs like bacteria and viruses. They’re easy to use: just drop a tablet in your water and wait for it to take effect.

I recommend looking for NSF-certified chemical disinfection tablets so you know that they work.

UV Treatment

UV treatment uses a UV lamp to kill pathogens like viruses, protozoa, and bacteria in water. UV doesn’t remove microorganisms from water – instead, it alters their DNA, making them unable to reproduce or cause harm when consumed.

UV water bottles are commonly used by hikers and backcountry explorers because of their simplicity – you just fill the bottle with water, tap the lid to purify your water, then drink it safely without pause.

Holding UV water bottle

Note that UV can’t be used to remove odors, tastes, chemicals, or heavy metals – this type of water filter is purely used for targeting microbiological impurities.

Solar Disinfection (SODIS)

An alternative to UV treatment is solar disinfection, or SODIS.

Developed in the 1980s, SODIS is an inexpensive, sustainable method of removing harmful microorganisms from drinking water. This method was initially popular in backcountry regions where the only clean drinking water source was bottled water.

Though it is still most commonly used in developing countries, you can choose to use SODIS while camping or traveling to remove bacteria, viruses and other pathogens from your water, no matter where in the world you live. If you use recycled plastic bottles the treatment costs nothing, and is very easy to set up.

The technique is simple: you just add water to a clear plastic bottle and expose this bottle to the sun.

This isn’t a quick fix – you have to wait up to 48 hours for your water to be clean enough to drink, depending on the intensity of your local area’s UV rays and the concentration and types of pathogens in your water.

DIY Filters

There are several DIY filters that you can use to filter or purify water in an emergency situation:

Activated Charcoal

Activated charcoal is a common water filter material, and you can make your own charcoal filter to provide similar clean drinking water benefits.

This water filtration method adsorbs water smells, germs, and toxic compounds. It can even reduce heavy metals and fluoride. With that said, activated charcoal shouldn’t be used for removing bacteria or viruses – because it can’t.

To make your own activated charcoal filter, place a charcoal lump from your campfire and put it in a (preferably clean!) sock. Pour water into the sock and catch the filtered water in a container underneath.

Hand-Made Sediment Filter

You can make your own sediment filter, too, if you don’t have access to a filter already.

Take a bucket and fill it with layers of gravel, activated carbon, and play sand. Drill a hole in the bottom of the bucket and pour water through the top. It’ll pass through the various layers, which will trap sediment like dirt and rust. This filter can’t be used to remove chemical contaminants.

Fruit Peel Filters

Ever wondered what you can do with your leftover fruit peels? As a last resort, you can use your old apple peels to purify contaminated water.

It’s worth noting that this method is only used in locations where there are only two options: drinking contaminated water or trying the fruit peel filter method. Choose other filtration systems before this DIY method.

📌 Why Should I Filter Water Anyway?

There are several reasons why you might want to filter your water supply.

The Environmental Protection Agency (EPA) has its own tap water standards that public water systems must legally adhere to. But does this mean that public drinking water is completely contaminant-free?

No.

No matter where you get your water from, it’ll still contain trace levels of all sorts of nasty contaminants, like volatile organic compounds (VOCs), disinfection byproducts, heavy metals, and chemicals like chlorine.

The Flint, Michigan water crisis is enough to tell us that not all public water systems treat their water so that it’s safe to drink. If you’re worried about your tap water quality, filtering your water will ease your concerns.

Water Quality Map
Source: United States Geological Survey (USGS)

Worse luck if you’re a well owner: the EPA Water Quality Standards don’t apply to you, and you’re responsible for treating your own water. This means your water could contain dangerous levels of all sorts of contaminants, and filtration is essential.

If, for whatever reason, you only want to filter your water some of the time, you can choose systems that allow you to switch between filtered and unfiltered water, like a faucet-mounted filter.

📰 Important Considerations When Selecting a Drinking Water Filter

There are so many ways to filter and purify your water that you’re probably wondering how on earth you can narrow your options down to one.

If you’re on the market for a water treatment solution today, I would recommend considering the following:

Water Source

The impurities you’re dealing with in your water source may determine which filtering or purifying solution you opt for. In some cases, a water filter application will be the best solution, while in others (such as if you’re dealing with microorganisms like bacteria), filtering water may not actually eliminate the problem.

If you’re considering buying a water filter or purifier, I’ll assume that you want to remove a particular contaminant.

Should you not know what’s in your water, however, I would recommend getting a lab test, which will give you the clearest indication of what you’re dealing with.

water testing with tap score

Method Effectiveness (Contaminants Removed)

Perhaps you’re just looking to remove a particular problem impurity, but equally, you might be looking for a water filter or purifier that can remove the largest number of impurities at once. In that case, consider filtering water with an RO system, or purifying it with a distiller.

It costs more money to buy filters that can do it all, and you may not need something so advanced. If you just need chlorine and lead removal, you can save a lot of money on carbon filters.

Additionally, if hard water is your biggest problem, avoid traditional filters and go for an ion exchange system.

Filter Capacity

Generally, the higher a filter’s capacity, the better.

Capacity is the amount of water which can pass through a filter before it needs to be replaced. This is often translated from number of gallons to a timeframe of months.

A system can filter water for longer if it has a good capacity, but capacity will vary from one filtering device to the next. Whole-house filtering systems naturally have the highest capacities, as they’re needed for whole-house use. Under-sink and countertop filters usually have slightly lower capacities, while pitcher filters generally have the lowest capacities.

If a filtering system lasts for over a year, it has a pretty decent capacity.

In most cases, however, especially with the smaller filters, you should expect a system to filter water for around three to six months before the filter needs replacing.

Flow Rate

The flow rate of a system will determine how quickly it’ll provide filtration.

The general consensus is that systems that are connected to your main waterline will naturally have a faster flow rate, as your water’s pressure will keep things moving quickly. Gravity filters, on the other hand, may take upwards of 10 minutes to filter a gallon batch, while distillation takes up to 6 hours.

Speed of filtration might not be massively important to you, but if you have a larger family, you may find that some systems are simply too slow to keep up with your demands.

Installation & Maintenance

Again, installation and maintenance varies widely depending on the filtration system you’re looking at.

While whole-home and under-sink systems are generally faster, they tend to be the most complex to install. This is especially the case when you’re dealing with a unit that has multiple components, like an RO filter.

Some filters, on the other hand, require no installation at all – like countertop filters and pitchers, which can be set up and ready to use in seconds.

In terms of maintaining a filter, if you’re looking at a filtering solution on this list, it’s a guarantee that you’ll have to replace the filters somewhere along the line.

Water filter maintenance

Some purification methods require far less maintenance, however; distillation and UV purification can go years without major work (unless you choose to use your distiller’s filter), and boiling or pasteurizing water requires no work at all.

Costs Involved

Finally, your budget is something to consider carefully when deciding which tap water treatment solution to invest in.

The bigger the system, the more expensive you can expect it to cost.

If you’re new to the idea of filtration, you might want to start by spending $20-$30 on a filter pitcher and testing it out. Faucet-mounted filters are another affordable option to consider.

You can then decide whether you’re keen to spend a bigger upfront cost on counter filters, reverse osmosis filters, under-sink filters, or whole-home filtration systems that generally require less frequent filter changes (or in the case of a purification solution, no filter changes whatsoever).