MSR and Platypus Water Filters | Product Overview

Photographer: Dan Patitucci

What makes a good filter in the backcountry? Is it the size? Ease of use? To the teams at MSR and Platypus, it’s the safety. The best filter is one that does its job easily and you get home without having a second thought about it. When ‘safety’ is in your name, it’s the first priority when designing a filter.

What Is Safe water?

In a backcountry scenario, water is usually considered safe to drink when it is free of pathogens, the things that actively make you sick. Other stuff in your water, like sediments and tannins, may be unappetizing but they won’t make you ill if ingested in small quantities. While filters and purifiers will take care of sediment, another step in the filtration method, such as adding a carbon element, is required to remove tastes and chemicals.

To ensure your safety in the backcountry, all MSR and Platypus water filters are thoroughly tested and verified to reach what is called the Minimal Level of Contaminants (MLC). This standard was created by the EPA and is the standard that all municipal water systems are held to in the United States. It is important to know though, while municipal water systems are held to a standard, there is no regulation for water filters and no need to prove what you claim on the box. As a leader in the water filtration space, all MSR and Platypus filters are put through stringent 10-day tests developed by the EPA and NSF, and are independently verified for accuracy (learn more about testing standards HERE). This means that no matter what type of filter you choose, or what the filter media is, when you choose a Platypus and MSR filter or purifier, you are getting safe, clean water trip after trip.

No matter how well tested, verified, and designed a filter is, how do you know if it’s still working properly? Portable filters and purifiers have known weaknesses (we’ll cover in the next section) and can be broken in the field. With other brands, if this occurs, you could have no way to tell until you’re sick miles from the trailhead. All MSR and Platypus filters have built-in integrity checks because the best filters are the ones that you know work.

Types of Filters

Before we dig into specific filter types and their benefits, it’s time to answer the age-old question, “what’s the difference between a filter and a purifier?” Simply put: virus protection. Filters will protect from microbes, bacteria, protozoan parasites. Purifiers will protect you from the same things as filters and viruses, which are the smallest of the waterborne pathogens.

Hollow fiber

Hollow fiber filters and purifiers have become the dominant style in the backcountry space, and the reasons are pretty clear: they are lightweight, they filter incredibly well, and provide fast flow rates. Because of this, hollow fiber filters are used in everything from ultralight personal filters, like the Platypus QuickDraw, to military-grade purifiers like the MSR Guardian. To learn more about the testing and development of MSR’s hollow fiber filters check out THIS article. The downside of hollow fiber filters is the actual fibers inside can break if dropped or if it dips below freezing and freezes the water inside, breaking the actual fibers of the filter.

Ceramic

Ceramic filters utilize a maze of microscopic holes that physically block contaminants. Due to this, ceramic filters can become clogged more easily than a hollow fiber filter, but flow rates can easily be restored with a little scrubbing. Ceramic filters also typically have a lower flow rate to begin with compared to hollow fiber.

Activated carbon

Activated carbon is not a recommended filtration method, at least on it’s own. Any sort of adsorptive filter (like carbon that absorbs contaminants) can quickly lose effectiveness when contamination or flow rates are high. This is why all MSR and Platypus filters that contain carbon only use it to filter secondary contaminants like chemicals and tannins.

Filter Comparison

MSR Guardian

The MSR Guardian purifiers offer state-of-the-art protection in two convenient packages, a pump and the Guardian Gravity. The Guardian was originally developed in conjunction with the US military as a new way to provide troops with clean water across the globe. The Guardian Gravity offers the same level of protection as the regular Guardian, just in a convenient gravity solution with a 10-liter dirty bag.

Both purifiers use a hollow fiber membrane with an activated charcoal element in order to provide virus protection and taste-free water. They also both have built-in backflush mechanisms, allowing the purifiers to clean themselves as they clean your water. The Guardian uses some water from each pump to clean the filter, while the Guardian Gravity has a second hose that drains out any built up sediment and bacteria.

MSR Miniworks ex

The direct descendant of the legendary WaterWorks filter (first introduced in 1991, and using ceramic since 1994), the MiniWorks EX is everything MSR stands for, in a filter: it is field maintainable without special tools, long-lasting, durable, and effective. Utilizing a ceramic element and activated carbon inside, it delivers clean and taste-free water, while the unique AirSpring Accumulator increases the flow rate, up to a rapid 1 liter per minute. For extra protection from viruses, the MiniWorks EX is also sold as a Purifier Kit that includes Aquatabs, creating a small and efficient purification system.

Platypus Gravityworks

Designed for backpacking groups, the GravityWorks system has been a staple at trailheads across the globe. The GravityWorks is available in 4 and 6 liter sizes, and utilizing a hollow fiber filter with an impressive flow rate of 1.75 liters per minute. There are also an impressive array of modular add-ons for GravityWorks systems, including Carbon Elements, Big Zip Evo direct attachments, and Bottle Adaptors so you can filter your way.

Platypus quickdraw

The best filter for ultralight purists and couples, the QuickDraw is the most versatile filter on the market without sacrificing any safety. Clocking in at an ultralight 2.4 oz (69 g) for just the filter and sporting a flow rate up to 3 liters per minute, it’s the same weight as the closest competitors and significantly faster. The QuickDraw is also safer than other squeeze-style filters, as it still includes and integrity check to confirm it’s functioning properly—a feature the competition lacks. The addition of the ConnectCap for 2024 has also boosted the QuickDraw’s versatility, allowing it to be offered now in 1-Liter, 2-Liter, and 3-Liter kits that easily fill whatever water carrier you prefer, bottles, bladders, or otherwise.

Platypus DayCap

The newest addition to the Platypus family, the DayCap is a perfect filter option for day hikes and casual adventures. Designed to fit wide-mouth Hydro Flask bottles, Nalgenes, or Yeti’s Yonder bottle, it’s a simple to use and carry solution to backcountry filtration. Despite it’s simple nature and ease of use, the DayCap still meet’s Platypus’s strict testing standards to ensure safety. A 1 liter per minute flow rate is as fast as the average person drinks so you’re able to use your bottle naturally and easily.