Big Zip EVO Reservoir: Cleaning and Care Tips
By Therm-a-Rest® - Sleeping Pads, Bags & Outdoor Comfort | Published: 2026-10-30
Category: How-to Guides
Keep your Platypus Big Zip EVO Reservoir tasting fresh and flowing fast with these simple cleaning and storage steps. Prevent mold and extend the life of your hydration system.
Quick answer
Clean your Big Zip EVO Reservoir after every trip using warm water and a mild cleaner, then air-dry it fully before storing. This prevents mold and keeps the 50% faster flow rate working as intended.
Why regular cleaning matters for your hydration system
The Big Zip EVO Reservoir's wide-mouth design and taste-free construction make it easy to keep clean, but skipping maintenance can lead to mold, off-flavors, and clogged tubing. Even a single trip with sugary sports drink can leave residue that feeds bacteria.
Because this reservoir delivers a 50% faster flow rate, any debris or biofilm in the tube or bite valve will slow it down. Regular care keeps every sip refreshing and efficient.
What to avoid when cleaning
Never use bleach, abrasive brushes, or dishwashers on your reservoir – they can damage the taste-free film and degrade the plastic over time. Stick to mild soap, specialized cleaning tablets, or a vinegar solution.
Also avoid storing the reservoir wet or sealed. Even a few drops of trapped moisture can become a breeding ground for mold within days.
Step-by-step cleaning routine
- 1. Rinse and disassemble: After each use, empty any remaining water and disconnect the hose from the reservoir. Remove the bite valve and slide the hose out of the quick-release fitting if your model has one. Rinse all parts with warm tap water to remove loose debris. Don't forget to remove the bite valve – it's a common spot for trapped moisture and mold.
- 2. Clean with a mild solution: Fill the reservoir with warm water and add a small amount of mild dish soap or a dedicated hydration-system cleaning tablet. Close the cap, shake gently, and let it sit for 5 minutes. Use a soft bottle brush to scrub the inside walls, then run the solution through the hose and bite valve. Avoid scrubbing the hose interior with a brush – it can scratch the inner surface. Instead, flush the solution through repeatedly.
- 3. Rinse thoroughly: Drain the soapy water and refill the reservoir with clean warm water. Shake, then flush the hose and bite valve again. Repeat until no soap bubbles appear. Any leftover soap can affect taste and attract residue. A third or fourth rinse is better than a hint of soap flavor on your next hike.
- 4. Air-dry completely: Turn the reservoir inside out (if possible) or prop it open with a clean drying rack or a paper towel roll to allow airflow. Hang the hose vertically so water can drip out. Leave all parts fully exposed to air for at least 24 hours before reassembling. Storing the reservoir while still damp is the #1 cause of mold growth. Wait until every surface feels bone-dry.
- 5. Store properly: Once dry, reassemble the hose and bite valve loosely – do not tighten the cap completely. Store the reservoir in a cool, dry place away from direct sunlight. For long-term storage between seasons, consider placing a clean, dry paper towel inside to absorb any residual moisture. A loosely closed cap allows air circulation and prevents moisture from getting trapped inside.
Product fact
- Big Zip™ EVO Reservoir: The Big Zip EVO Reservoir features a premium, taste-free construction and a 50% faster flow rate. Keeping the interior clean preserves that taste-free quality and ensures the faster flow rate isn't slowed by debris or biofilm.
Big Zip™ EVO Reservoir
