Frequently Asked Questions


Depending on the water clarity/quality, backflush a ¼ liter of water for every 6 liters filtered.

No. All Platypus hydration products are 100% BPA-, BPS- and phthalate-free, and do not use polycarbonate.

Backflushing regularly maintains optimal performance of the filter cartridge. This is especially true when filtering murky or very silty water. Backflushing rinses out particulate that collects on the outside of the Hollow Fiber filter media. Infrequent backflushing makes it more difficult to restore the filter’s flow rate.

Based on results from our in-house water lab, we recommend backflushing a ¼ liter of water for every 6L filtered; this largely depends on the water clarify/quality. Our lab has found that with frequent backflushing, you can expect better maintenance of flow performance and longer life from your filter cartridge.

This color of water typically comes from a high concentration of decaying vegetation adjacent to, or in, a water source, resulting in a variety of organic acids. These acids, and the accompanying water conditions, are very hard on ALL types of water filters. Get your water elsewhere if you can.

However, if no alternatives exist, we recommend backflushing/cleaning your filter after every use in the field. This will help minimize the impact of these impurities.

Then, when you return home, add 2 drops of unscented household bleach to one liter of water and backflush this solution through the filter. This will help break up organics that might be clogging the filter and prepare your system for long-term storage.

Note: extended use of tea-colored water can permanently impair Hollow Fiber filter media.

No. Hollow Fiber filter media does not remove tastes from water.

However, the use or addition of an additional filter with carbon activated technology will absorb most of the unwanted tastes you may find in filtered backcountry water. For our GravityWorks systems, our Carbon Element accessory is available for those that prefer cleaner-tasting filtered water.

To disinfect your Platypus filtration system, fill it with a solution of unscented household bleach and water, using a concentration of 2-5 drops per liter of water. Close and swirl for 10 seconds. Leave filled overnight.

Filter solution through any filters and/or hoses, then rinse system (including filters and hoses) three times with hot water. Let air dry.

Note: for an eco-friendlier option, use a chlorine-free, hydrogen peroxide-based bleach alternative.

E-mail: Cascade Designs Service Center
Tel: 1-800-531-953

For customers outside North America, please consult our International Distributor listings.

Cleaning regularly maintains optimal performance of the filter cartridge. This is especially true when filtering murky or very silty water. Cleaning dislodges particulate that collects on the outside of the Hollow Fiber filter media. Infrequent cleaning makes it more difficult to restore the filter’s flow rate.

Based on results from our in-house water lab, we recommend cleaning anywhere from every 6 liters to as often as after each use, but this can vary depending on water quality. Our lab has found that with frequent cleaning of your filter, you can expect more consistent flow performance and a longer life from your filter.

A used GravityWorks™ or Meta™ Bottle filter will have wet Hollow Fiber filter media, which can freeze and break the fibers of the filter media (permanently damaging the filter). Therefore, it is important to prevent Hollow Fiber filters from freezing.

If you are traveling in areas where you are expecting freezing or near-freezing temperatures, we recommend carrying or stowing the filter cartridge near your body (e.g., in a chest pocket) and bringing the filter cartridge with you into your tent, or even your sleeping bag. (Be sure to put the filter cartridge in a watertight bag to prevent leaks.)

If you think your filter may have been damaged by freezing, perform a filter integrity test before the next use (see instructions for your filter product). We recommend carrying a replacement filter as a backup in case of a failed integrity test.

Hollow Fiber filters can be sensitive to hard drops. Any drops from heights over 5 feet (1.5 m) and direct drops onto cement or rocks should be avoided with GravityWorks™ and Meta™ Bottle filters.

If you think your filter may have been damaged from a drop, perform a filter integrity test before the next use (see instructions for your filter product). We recommend carrying a replacement filter as a backup in case of a failed integrity test.

Note: do not remove the protective bumpers on the GravityWorks filters.

Yes there is! The Big Zip™ EVO Filter Connector Kit is a nifty accessory that allows you to filter directly from your GravityWorks™ into your Big Zip EVO without ever having to remove your reservoir from your pack.

To do so, you first need to remove your drink tube from your reservoir via the quick-disconnect. Then, plug the connection point on the connector kit's hose directly into quick-disconnect point (you will hear a click). Next, attach the connector kit's hose to the base of your GravityWorks filter cartridge. Let gravity do the rest, as you're now on your way to clean, taste-free hydration.

Watch this video for a step-by-step video instructing you how to use this product.

Yes. Periodically adding a little Vaseline to the tracks will keep them supple and easy to close. Wipe away any excess Vaseline. In the field, a little lip balm or water can do the trick.

Many replacement parts can be purchased directly from us online on our Accessories page or from one our retailers. If you cannot find what you’re looking for, our friendly customer service team can assist you:


For customers outside North America, please consult our International Distributor listings.

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