How to Store and Maintain a Hydration Reservoir Between Trips

By Therm-a-Rest® - Sleeping Pads, Bags & Outdoor Comfort | Published: 2026-10-15

Category: Tips & Care

A step-by-step routine to clean, dry, and store your hydration reservoir so it stays mold-free and ready for your next adventure.

Quick answer

After each trip, rinse your reservoir with warm water and mild soap, scrub all interior surfaces, then dry it completely before storing it open and away from direct sunlight. This simple routine prevents mold, odors, and material damage, so your reservoir is ready when you are.

Why drying is the step most people rush

Mold and bacteria need moisture to grow, so the single most important thing you can do is dry the reservoir thoroughly. After washing, shake out excess water and wipe the interior with a clean, lint-free cloth. Then prop the reservoir open with a drying rack or a clean spoon so air can circulate inside. If you store it even slightly damp, you are inviting the exact problems you are trying to avoid. Let it air-dry completely—this can take several hours or overnight.

Choose the right cleaning supplies

Not all soaps are safe for hydration reservoirs. Avoid harsh detergents, bleach, or anything with fragrances or moisturizers, as these can leave residues that affect taste and may degrade the plastic. Instead, use a mild dish soap or a dedicated reservoir cleaning solution. A soft bottle brush or a reservoir-specific cleaning kit makes it easier to reach all interior surfaces, including the baffles and corners. Never use a brush with stiff bristles that could scratch the interior.

Step-by-step hydration reservoir care

Rinse immediately after each use: As soon as you get home, empty any remaining water and rinse the reservoir with warm water. This prevents sugars, electrolytes, or other drink additives from drying and becoming sticky or causing bacterial growth. Checkpoint: If you used a sports drink or juice, rinse twice to remove all residue.
Wash with mild soap and a soft brush: Fill the reservoir with warm water and a few drops of mild dish soap. Use a soft bottle brush to gently scrub the interior walls, corners, and the drink tube. Pay attention to the bite valve and cap threads, where grime often hides. Common mistake: Using hot water or harsh cleaners can warp the plastic and leave harmful residues.
Rinse thoroughly until no suds remain: Empty the soapy water and rinse the reservoir, tube, and valve multiple times with clean water. Any leftover soap can leave an unpleasant taste and may irritate your stomach on the next trip. Checkpoint: Sniff the reservoir—if it smells like soap, rinse again.
Dry completely inside and out: Shake out excess water and use a clean towel to dry the exterior. For the interior, prop the reservoir open with a drying rack or a clean utensil so air can circulate. Hang the tube to drain. Allow it to air-dry fully—this may take several hours or overnight. Common mistake: Storing while damp is the number one cause of mold and mildew.
Store open and away from heat: Once dry, store the reservoir unzipped or with the cap off to allow continuous airflow. Keep it in a cool, dry place away from direct sunlight and extreme temperatures, which can degrade the material over time. Avoid compressing it in a tight stuff sack for long periods. Checkpoint: If you store it hanging, make sure the tube isn't kinked, which can cause cracks.
Deep clean before storage and before reuse: If you haven't used your reservoir in a few months, give it a deep clean with a reservoir cleaning kit or a mixture of warm water and mild soap. Rinse thoroughly and dry completely before your next adventure. Next step: Mark your calendar to check your reservoir every few months, especially before a big trip.

Product facts

Guardian™ Purifier Maintenance Kit: The Guardian Purifier Maintenance Kit is a complete kit designed to help you maintain your Guardian Purifier, including essential components for routine upkeep. If you use a purifier with your reservoir system, keeping it maintained ensures reliable performance and extends the life of your gear.