When faced with a survival situation, the conventional wisdom is that water is your best friend, and while you can go for three weeks without food, you can only survive for three days without water.
For this reason, it’s always a good idea to stockpile your water and have water packs so that you don’t miss hydration opportunities.
With that considered, it’s still a good idea not to keep all of your eggs in a single basket, and that’s where a good gravity filter is going to really benefit your chances of survival.
In this guide, we’re going to not only show you some of the best gravity water filter models on the market, but we’re also going to help you identify the features to look for in your next purchase.
Last update on 2021-09-29 / Affiliate links / Images from Amazon Product Advertising API
- 1 The Best Gravity Water Filter Reviews
- 2 LifeStraw Family 1.0 Portable Gravity Powered Water Purifier for Emergency Preparedness and Camping
- 3 LifeStraw Flex Advanced Filter with Gravity Bag
- 4 Renovo Water MUV Tote 10 Liter Gravity Water Filter Combo
- 5 Katadyn BeFree 3.0L Water Filter
- 6 miniwell Gravity Water Filter Straw
- 7 How Does a Gravity Filter Work?
- 8 What to Look for in the Best Gravity Water Filter Backpacking
- 9 Final Thoughts
The Best Gravity Water Filter Reviews
The first product is a good gravity filter that’s designed to filter out more than 99.99 percent of contaminants. This includes bacteria, some viruses, and protozoan species like cryptosporidium, which is a microorganism that is the result of animal feces. During its lifetime, you can expect this purifier to filter out 18,000 liters of water, which amounts to three years of drinking water for a family of four. This is very reasonable considering how inexpensive the product is.
When it comes to the quality of the mesh used, this filtering agent will prevent anything more substantial than 0.02 microns from getting through with the water. Once water is added to the top of the unit, you can expect a flow rate of about nine to 12 liters of fresh water per hour, which can efficiently hydrate three or four people for a day.
This is a bagless gravity filter; you simply pour water into the top container, and it’ll work its way through a thin tube into the filtration system. The product also is completely unpowered, so you won’t need batteries or an outlet to run it.
- It has a high flow rate
- Some of the proceeds go to the purification of water for school children
- It’s a reasonably lightweight filter
- The main decanter is a bit wide It can take a little bit of work to get it flowing correctly
This next product is another filter that is produced by LifeStraw. This unit uses a bag to hold water, which can make it quicker to use than the decanter-based filter unit that we covered in our first review. Like that product, this filter will filter out any object larger than 0.02 microns, which will include about 99.99 percent of bacteria, viruses, protozoa, and microplastics.
This filter accomplishes this via a hollow fiber membrane that has a very fine pore size. In addition to its ability to safely filter water, it also comes with a carbon fiber capsule that’s designed to make the water you’re cleaning more palatable. This is perfect for separating out elements like lead as well as chemicals like chlorine.
Insofar as lastingness, this filter can clean water for several years; in fact, it’s rated to last for at least 2,000 gallons. The flow rate on the product will allow you to produce a liter every two minutes, which means that you’ll be able to produce an impressive 30 liters per hour.
- The product has an excellent flow rate
- It’s very easy to use
- The carbon fiber capsule really improves the taste of the filtered water
- The seal on the filter bag is a bit flimsy
This product really stands out because of the fact that its filter bag holds about 10 liters of water. This means that you’ll be able to quickly produce high amounts of filtered water for a large-sized family. In addition , this is still a great product for portability because it incorporates a shoulder strap, which means that you can carry this independently of your survival bag.
This is a product that will filter out anything larger than 0.01 microns, which can include a wide variety of organic and nonorganic contaminants. In addition to these features, the product can also be used as both a standard gravity unit or a straw filter, which means that you can use it to purify water on the fly without filling the bag. Finally, it can also be threaded directly onto a water bottle so that you can be sure that any water that you’ve collected is safely filtered for drinking.
- This product has its own shoulder strap
- It has multiple versatile uses
- It’ll filter out 10,000 gallons of water during its lifetime
- It has a quality suspension system
- The connections could be better
Katadyn BeFree 3.0L Water Filter
This three-liter product from Katadyn is designed with backpackers in mind, but it also makes for a very reliable product that can get you through a survival situation. The mesh has a membrane that has pores that will keep anything more substantial than 0.1 microns from entering your drinking water. This means that several species of virus and bacteria will be filtered out, and you’ll even be able to filter out some non-biological contaminants as well.
This is also a filter that stands out for durability; the water bag won’t tear very easily, yet it can be folded up neatly when not in use. This means that this is one of the most portable gravity filters in our guide and one of the best gravity water filter backpacking.
- The product has a very easy-to-clean filter – you just shake it in your water source
- The handle makes it very easy to fill the bag from a water source
- The flask has graduation marks so that you can measure out your water
- The mesh could be a bit finer
Our final product is a gravity filter from miniwell. This product stands out because it comes with a convenient tree strap so that you can hang it up with relative ease. This process is accomplished with a built-in carabiner, so setup is done with a couple of snaps. It also is the only product that has a clean water collapsible bottle that you can take with you with ease.
When it comes to everyday functionality, this is a 0.1-micron product, so it’ll filter out most pollutants. Additionally, it’s rated to provide 2,000 liters of filtration over its active lifetimes, and it’s very durable and shouldn’t be damaged by various factors during your outings. The product also stands out because of its easy-fill system; you simply slide off the sealing lock at the top and slosh in water from your water source.
- This comes with a tree strap for hanging
- It’s easy to see what’s in the filter bag
- It comes with its own collapsible decanter
- It can clog easily, so it may take some time to filter
How Does a Gravity Filter Work?
Gravity filters are unique when compared to straw, inline, pump, and bottle filters because they take a little bit more time to set up. This is because the filter usually has a two- or three-tiered system of filtration.
These filters literally use gravity to pull water through a mesh filter. With one of these, the water will rest above the filter in a bag or another style of container and dribble downwards similarly to an intravenous bag. One of the best features of an excellent gravity-fed filter is that these products are designed to work very well without you being in the direct area.
As a result, one of these products will produce filtered water while you go about other essential survival tasks.
What to Look for in the Best Gravity Water Filter Backpacking
A good gravity filter will be able to filter out bacteria and viruses as well as many other harmful contaminants, but not all filters are created equally. Here are a few crucial features that you should look out for before you buy:
The Mesh Quality
The mesh is the most crucial factor of your filter, so you’ll want to spend a few extra bucks if it means that the filter will have a finer mesh that can block out more contaminants. Remember, while you should be checking the water for muddiness and appearance before you try to drink it, even a perfectly clear body of water can cause you to become very sick.
A good mesh has spaces that are measured in microns. For example, the average human hair is anywhere between 40 and 50 microns wide, and one of the finest substances, which is lead, has a micron width of about 0.001 microns. While the pore holes in your filter won’t entirely block everything, the smaller the holes are, the better.
Viruses, which are far smaller than bacteria, can be a real danger in specific water systems. Fortunately, in North America, viral contamination isn’t very likely, but in a survival situation, you never know how things can quickly change. Ideally, shoot for a product that has pore holes that will block contaminants that are 0.01 microns in width; this will prevent some of the more problematic parasites from entering your system such as cryptosporidium.
How Easy is it to Replace the Filter Assembly?
Trust us, the last thing you want is to struggle to replace the filter assembly, and if a filter is particularly complex to replace, you’re going to get frustrated quickly.
As a rule, the pricier filters tend to be somewhat easier to replace, and these are also the kind that tends to have a finer mesh that blocks more contaminants, so you may want to consider purchasing something like this. Also, you’ll also want to look at the frequency of the filter replacement, and just about every product is going to outline the lifespan of their filter assembly.
Try to find products that last a little bit longer so that you can avoid a headache.
The Level of Portability
This is fairly essential, especially considering that these types of filters are specifically designed for backpacking and survival. While there are bulkier filters out there on the market, you’ll want one that you can pack away in a bug out bag without worrying about cutting down on space for other necessities .
Additionally, the filter should also be lightweight to facilitate a lighter carry situation, which can be crucial, especially in a flight situation.
While gravity filters tend to be slightly bigger than other filter types, you can still find products, like the ones in our reviews, that will still pack away tightly.
Gravity filters are one of the few filter types that utilize this measurement, but it makes sense because gravity is utilized to push water through a filtration system to purify it.
With these types of products, the flow rate is usually measured in liters per hour, and if you want the right level of flow, you should purchase a product that can at least produce about four liters of water per hour.
This amount of liquid can help an adult stay hydrated for a full day – with only an hour’s worth of collection.
Stay hydrated! Keeping up your water levels is absolutely crucial, and we hope our guide to gravity filters has provided you with the essential info you need to stay alive during a survival event.
The five products that we have reviewed all stand out because they provide a truly reliable way of getting water, and any of them should meet your needs.
With that said, out of all the reviewed products, the Renovo Water MUV Tote stood out the most. This is because it has a great mesh filter that lasts a long time, which means that it can be relied on when things get rough. Additionally, the bag has a 10-liter capacity, which will provide enough filtered water for two people to survive off of in a day.