Why Filtering Your Water Isn’t Enough: Water Filters vs. Purifiers

Why Filtering Your Water Isn’t Enough: Water Filters vs. Purifiers

Clean Water Isn’t Safe Water

There’s something amazing about watching a water filter turn nasty, brown water into clear, sparkling-clean water right before your eyes. Unfortunately though, this clean appearance doesn’t mean the water is safe to drink.

Clean water and dirty water

The image on the left may look clean, but that doesn’t mean the water is safe to drink.

In fact, most of the health hazards that exist in water (aka waterborne pathogens) are microscopic, meaning they’re invisible to the naked eye. Some of these hazards are so tiny that traditional water filters aren’t effective at removing them.

Backcountry Water Safety

Staying hydrated with pure water is one of the most important pieces to having a successful adventure, whether you’re backpacking, camping, hiking, or traveling abroad. That’s why it’s important to consider the benefits of water filters vs. water purifiers when choosing a personal water treatment system.

In this article, we’ll take a closer look into what waterborne pathogens exist and how they can be removed so you can have confidence the water you’re drinking not only looks clean but is actually pure, safe drinking water.

Microscopic Dangers



Viruses like this one are hundreds of times smaller than bacteria.

Viruses are parasitic organisms 100 times smaller than bacteria, with most viruses measuring between 0.004 and 0.1 microns. They are incredibly hardy organisms that may survive through both freezing and drying. Waterborne viruses that cause disease in humans include rotavirus, norovirus, and Hepatitis A.

Viruses are 100 times smaller than bacteria.


bacteriaBacteria are one of many microscopic dangers that can be present in clean-looking water.

Bacteria are single-celled organisms that exist almost everywhere on earth. Some bacteria help humans, while others are the culprits for many waterborne diseases. These include E. coli, salmonella, and dysentery, none of which make for an enjoyable backcountry experience. Most bacteria range in size from 0.2 to 10 microns (1 micron = 0.00039 inches).

Protozoa & Cysts

Protozoa are one-celled animals that live mainly in water. When they infect humans, they can cause diseases ranging from mild to life-threatening. Common parasitic protozoa include giardia and cryptosporidium.

Some protozoa form cysts, a protective wall that makes them resistant to disinfectants commonly used in treating drinking water. Cysts are generally between 2 and 50 microns in size.


Not all waterborne health hazards are alive. Chemicals may be present in water and represent a health concern in high concentrations.

Heavy Metals

This health hazard is certainly not the least dangerous, and some heavy metals have found their way into water. The health danger they represent should not be ignored.


No one wants to drink water with dirt floating in it. However, dirt isn’t why we included sediments on this list of microscopic dangers. Microplastics are tiny plastic particles smaller than a sesame seed that can be found in water due to pollution.

Microplastics are increasingly found in drinking water. Though they have not been proven to be a health danger, there is concern that chemicals or other pathogens may catch a ride on these tiny plastic pieces into your body, making removing them from your water the safe choice.

How Water Filters Work

With all those invisible dangers floating around in water, it’s no wonder water filters for hiking, backpacking, hunting, and international travel exist. These filters provide valuable protection but, unfortunately, may not be enough to protect you due to the very nature of how filters work.

So how does a water filter work?

Most water filters act as sieves (imagine a much smaller version of the colander you probably have in your kitchen).


Filters operate using the same principle as a kitchen colander – by physically removing items from the water.

They physically strain out waterborne hazards by forcing the water (using suction or gravity power) through a membrane that has tiny holes. These holes are typically 0.2 microns in size. The 0.2 micron size is big enough to let the water molecules through but small enough to trap sediment, bacteria, and protozoa/cysts.

If you’ve found it difficult to drink through a water filter, it’s because forcing the water through the tiny holes using the power of your own suction is a lot of work – and the smaller the holes, the more work it is.

Unfortunately, even the tiny 0.2 micron holes in most water filters aren’t small enough to catch viruses, heavy metals, or chemicals, meaning you could still get sick drinking filtered water. Filtering your water isn’t enough to be confident that what you’re drinking is safe. That’s where RapidPure water purifiers and the benefits of water purification come in.

RapidPure: More Than a Filter

RapidPure’s line of water purifiers goes a step beyond water filters by removing not only bacteria, sediment, and protozoa/cysts, but also viruses, heavy metals, and chemicals so you can be sure your water is safe to drink, no matter where you travel.

Rapidpure bottle in use

RapidPure Purifier+ Water Bottles purify as you drink, removing 99.9% of viruses, bacteria, parasites, and more.

Water Filters vs. Water Purifiers

Leading Water Filters
RapidPure Water Purifiers
Sediment Yes Yes
Bacteria Yes Yes
Protozoa/Cysts Yes Yes
Viruses No Yes
Chemicals No Yes
Heavy Metals No Yes


RapidPure water purifiers look a lot like traditional water filters, but like with the waterborne pathogens it removes, the difference is in what you can’t see.

RapidPure’s purification membrane uses the latest in water treatment technology, called UltraCeram®. As the water passes through RapidPure’s membrane, the UltraCeram acts like a magnet, attracting and trapping waterborne pathogens by targeting the negative electromagnetic charges these contaminants emit.

Dirty, contaminated water passes through UltraCeram and comes out clean and safe to drink.

With the viruses, bacteria, protozoa/cysts, heavy metals, and chemicals removed by the UltraCeram, the only thing the RapidPure membrane has to physically strain out is the sediment. This allows the pore size to be much larger than 0.2 microns, meaning the force needed to push the water through the holes much less.

RapidPure straw in useThe RapidPure Purifier+ Ultralight Straw lets you purify and filter water straight from the source.

You read that right – RapidPure purifiers create safer water while being easier to drink through!

Travel Far & Drink Safe

So whether you’re prepping to thru-hike the AT, travel to South America, or simply enjoy some backcountry water in your own state, make sure you’re in the know what dangers exist and how to prevent them. Packing and using a RapidPure water purifier is only one piece of travel safety (albeit an important one).

RapidPure POD System in use
The RapidPure Purifier+ Multi-Use POD System is a 4-way multifunctional system that transforms into a bottle, straw, inline hydration pack attachment, or gravity purifier.
A little research and the right gear can help you go a long way – wishing you safe travels and amazing adventures ahead of you.