Water filters are perhaps one of the most overlooked, but most essential items you should be bringing with you in a bug out bag.
If you homestead, you should have a half-dozen of these scattered in different safe spots all around the home.
But a DIY water filter gives you one thing that a built-for-you water filter doesn’t: peace of mind that you can grant yourself. You don’t need a contraption (although they are useful), you’re a one-man army.
We’re going to go through water filtration as a whole, why it’s important, but also how you can make your own filter from the ground up (in more ways than one).
What is Water Filtration?
Water isn’t clean. At least, not clean enough to drink. Nearly all natural water contains some form of particle matter, which can be bacteria, algae, fungi, viruses, paradistes, pathogens, and more. Some contaminants are visible, while most of them aren’t.
Water filtration is the act of siphoning the harmful components of natural water, and making it clean enough to drink without negatively impacting the body. This is done with a water filter: a device, material, or process used to extract everything harmful out of natural water.
Filtering for Bacteria
Bacteria is prevalent in most water sources. Not all bacteria is bad for nature, which is why it exists in that water in the first place. However, humans are actually quite fragile, and a small dose of bacteria in something like drinking water can be a death sentence.
Filtering for bacteria include E. coli, vibrio, salmonella, enterococci, shigella, and others that are known to cause life-threatening and painful illnesses.
The terrifying thing is that a select couple of bacterial illnesses that spread in water – giardia and cryptosporidium – are resistant to so many forms of disinfection, which is why we have to use specific measures when cleaning cooking surfaces after using any form of water on them.
Filtering for Viruses
Viruses cause disease. There are seven primary viruses that are actually extremely common in unfiltered water. They can be born from bacteria found in nature, animal urine and feces, and can survive in water for far too long.
- Hepatitis A
- E. Coli
- Typhoid Fever
Each of these can be fatal. If you ingest them through water, you have a limited amount of time to get treatment for most of them.
There are no clear indicators of these being present in your water; they’re entirely invisible to the naked eye. Filtering is your only defense against them.
Filtering for Heavy Metals
Drinking water can pass through a filter while carrying trace elements of heavy metals. These are detrimental to our health, especially in high doses as we can find in the wilderness through unfiltered water.
Technically, fluoride counts as a heavy metal, and everyone knows that it’s pumped into the public water in just about every part of the United States. While different heavy metals pose different threats, they all have their negative sides.
Arsenic, lead, mercury, and tons of other well-known harmful chemicals are classified as heavy metals. Because mercury is abundant in water sources (generally the ocean more than rivers), you run a high risk of prolonged mercury poisoning if you aren’t careful.
Types of Water Filters You Can Build
There are a handful of different water filters you can build. We’ll go over some quick DIY build guides later on, but for now, it’s good to get acquainted with what’s available.
A biosand filter, commonly referred to as a bio filter, is actually made up of sand and gravel. If you ever notice, rivers that produce fresh water look different to freshwater lakes, which run stagnant. That’s because water is constantly moving through a natural sand and gravel filter.
Now, is this enough to count river water as clean?
No. There are too many variables; you should never just drink river water. However, in a controlled environment, sand and gravel can filter for bacteria, pathogens, and waterborne illnesses.
Here is an accurate breakdown of a bio filter on a large scale. These are difficult to DIY, but not impossible. You’ll see these on large-scale production more than in prepper’s survival kits.
If you’ve ever cared for or had a baby of your own, then you know that formula needs to be prepared with distilled water. It usually has a different cap color than the spring water at the store.
Distilled water is virtually free from everything that isn’t “pure water”, meaning you have no leads, arsenic residue, fluoride, and of course, no bacteria, pathogens, or waterborne viruses.
Distilling is done through boiling water and collecting the steam. When water boils, the heat kills most of what we just disclosed. The thing is, water that boils down can still contain leads and heavy metals. These don’t just dissipate from a bit of heat.
But they also don’t travel through evaporation from steam. Steam is collected, and turns back into water in a clean tank. There you have it – virtually pure water. Keep in mind, there are some caveats, such as storage and mineral/container leaching.
They’re called charcoal filters, but they’re actually activated carbon filters. This isn’t as simple as running some water through a few pieces of coal; you’d just end up with carbon-filled black water at that point (keep in mind that coal and charcoal are different).
Activated carbon is charcoal that has been oxygen treated after being raised to 1,000 degrees Fahrenheit, then hit with argon and nitrogen treatments. This three-step process is key. This opens up microscopic pores all along the pieces of charcoal, and allows water to enter.
Activated charcoal uses a method called adsorption, and yes, you’re reading that right. While absorption pulls water in, adsorption basically uses carbon to bind all organic and inorganic compounds together.
H20 is not a compound (well, it is, but it’s complicated), so it doesn’t bind to carbon the same way that everything else does. Water flows, viruses, pathogens, and dirt are filtered, and clean water comes through the bottom.
Last but not least, multilayer filters may be some of the most complicated ones to pull off. Remember the bio filter from earlier? That is technically categorized as a multilayer filter, but in this classification, there are tons of variables.
A multilayer filter is usually a sand and gravel filter combined with hydro-anthracite, Hydro-anthracite adds extra filter layers to ensure water cleanliness.
For higher arsenic filtration in a sand and gravel filter, it can be filtered with an additive of granular ferric hydroxide (GFH). Greensand can be applied if water is suspected to have a heightened level of manganese.
Multilayer filters aren’t as practical for DIYing. However, if you plan on having a fallout shelter in your homestead, having these to filter through dirty water may be beneficial.
Consider Time, Size, and Complexity in Survival Situations
Look, some of the filtration systems we just reviewed are extremely complex, and require some degree of engineering know-how to properly build.
You can’t just take sand from outside, pour it on gravel, and hold it over a water collector. It doesn’t work like that. Before you decide on any DIY water filter system, you should consider the following.
- System Building Time: If you’re building a complex water filter system from scratch, you have to source the parts, machine everything down, test it, rerun the results, test it again, and make sure it’s ready to go when you need it. I’m not saying that it’s not worth it, but it is time-consuming.
- Design Complexity: What are you capable of creating? Are you skilled with a variety of tools or not? Some of these filtration systems can have difficult designs. While we did our best to stick to quick-and-easy DIY methods later on in the guide, long-term sustainable water filter systems are hard to design.
- Usefulness: Do you plan on bringing your filter with you in a bug out bag? If so, how much does it weigh, what are its dimensions? For larger water filter systems, you’d be better off building it and affixing it to an area of your homestead or a bug out shack somewhere.
Determining Water Quality After Filtration
There are three primary ways to tell if your water has actually been filtered properly just from the naked human eye.
While we can’t look at water and say 100% whether it’s clean or not, it’s important to identify what looks drinkable so you aren’t wasting water test kit supplies on dirty water.
Smell, Taste, and Appearance
Everyone thinks that they can spot dirty water, but it’s not quite so clear. Even right now, you can take tap water out of your sink, put it up to the light in a clear glass, and see particles floating around in it.
That’s not purified; that contains chlorine, in many areas in the US, it contains traces of lead.
It just goes to show that you still need to test it. That being said, you don’t want to waste your test kit strips on water that you can clearly tell is dirty or muddied. Ask yourself these questions when inspecting your water to see if it’s worth putting to the test.
- Does it smell? You’ll be able to hover your nose right over it, and get a very pungent odor that rises up from dirty water.
- Can I see particles in it? If you see any particles floating in your water, it’s not clean. It needs to be filtered. There’s a reason that snap-on water filters sell all over the United States for kitchen faucets.
- Does it look clear? Cloudy water or otherwise discolored water is not potable. You should not drink it to test things out; in fact, you should either refilter it, or cut your losses and gather water from another source immediately.
- Does it have a funny taste? If the water looks clean, free of particles, and doesn’t have an odor, you can try tasting it to see if it’s clean. The issue here is that some bacteria may not alter the taste if it’s just trace amounts. You’ll be able to immediately tell if the water you just drank is clean or not.
Water Test Kits
Water test kits are extremely important. Your senses can fail you, but a preserved water testing kit (which hasn’t expired) will be far more beneficial. There’s a way to conserve these test kit strips as well so that you can save supplies, especially for a long-term SHTF situation.
While these can get a bit expensive, water test kits are literally a life-saving tool. You have to shop around for a while to find the one that best fits your budget, but tons of companies are doing this, so the healthy competition should benefit you.
A water testing kit will tell you if your water is laced with toxic metals, bacteria, viruses, toxic organic compounds, toxic inorganic compounds, and volatile organic compounds. Water test kits are an absolute necessity if you’re serious about this.
How to Build Your Own Easy Water Filter System
It’s all come down to this – making your own water filter. Three are a few different methods we can use, so we’ll go over a hard-and-fast guide for each.
Remember that if you don’t build a quality filter, you run a high risk of contracting waterborne illnesses. The naked human eye can’t see in microns, which is why you need to have water test kits with you no matter what.
Bio filters use sand and gravel to sift through water and extract heavy metals, chemicals, and viruses from the water. This is how to make one.
- Get a narrow bucket; it doesn’t have to be too wide.
- Puncture ten small holes in the center of the bucket’s bottom.
- Cut circular mesh netting to cover the entire bottom of the bucket. This has to be very tightly woven to prevent sand from escaping.
- Fill the bottom of the bucket with sand.
- Place another mesh net on top of the sand.
- Top that mesh net with a layer of gravel.
- Run water through the filter system until it comes out relatively clear. This removes dust and dirt from the gravel and sand.
- You’re ready to go.
It’s important to note that bio filters are imperfect and are not the only filtration method you should use. This is like a precursor to other methods, such as distilling and charcoal filtering.
Distilled water has a funny taste to it because it lacks minerals that you would find in spring water, and it certainly tastes different from tap water (like night and day). This is how you make one.
- Get a stainless steel pot (ideally 5 QT or larger) and grab the lid.
- Fill the pot with water. You can do a tap water test at home with a PPM monitor.
- Place a sturdy glass bowl in the center of the water. You want it floating in the water, but you do not want any water to get inside of it.
- Place the lid upside-down on the pot once the water begins to boil.
- Watch as the water pools up, runs down the upsid-edown convex lid, and begins to fill the bowl.
- Test the water in the bowl. Repeat this as needed.
As a last little tip, you want the water just boiling. If it’s at a rapid bubbling boil, it could over splash into your bowl and ruin the results.
Charcoal filters are everywhere because they’re extremely effective. You may even notice a charcoal filter in your water bottle. This is how you make one.
- Get a plastic pitcher. Screw one small hole in the center of the bottom.
- Take a coffee filter and layer it over the top of the hole. Make sure it’s pressed against the bottom firmly.
- Fill the pitcher up with activated charcoal. Do not exceed 50% capacity.
- Soak the charcoal in water for about fifteen minutes.
- Fill the pitcher so that the water volume does not exceed 75% of the pitcher’s total volume (50% of which being dedicated for the charcoal).
- Use a catcher on the bottom to collect filtered water. This takes time, but it’s effective.
Similar to the bio filter we made earlier, we can use multiple layers of materials to make a seriously powerful multilayer filter to capture niche chemicals like manganese. In fact, you can follow all of the previous steps in the biofilter section up until step 3.
- Once your bucket has mesh netting on the bottom, apply a layer of activated charcoal.
- Apply another layer of mesh netting on top.
- Layer the top of that mesh with sand.
- Apply another layer of mesh netting on top of the sand.
- Apply a layer of gravel on top of the netting.
- Run water through the filter until it runs clean; you will notice black flecks, dirt, and discolored water at first.
- You’re good to go.
Multilayer filters are better than biofilters because you can normally drink the water straight away, provided that your activated charcoal is working as intended.
Better Equipped for Every Situation
Keeping bacteria, viruses, and pathogens out of the water you drink is one of the most important things you can do in a SHTF situation. Waterborne illnesses and disease are some of the most lethal, and easy to contract (especially in the wilderness).
When you can build your own water filter, nothing stands in your way. It’s time to survive, for you and your family, and you’ll be more ready than anyone else.