Mold Be Gone: How To Clean a Hydration Bladder

Key Points

  • Hydration bladders offer a versatile and easy way to stay hydrated on any outdoor adventure.

  • Before purchasing a hydration pack, you must understand how to clean a hydration bladder.

  • Avoid the headache of mold and clean your hydration system before and immediately after every use. 

  • Clean a hydration bladder with cleaning agent options to purchase or that may already be in your home. 

You might be finding yourself itching to get back out on the trails. You're dreaming of striking views, warm breezes, and the mental clarity that comes from being in nature. On top of all of that, you're excited to try out the new hiking shoes you bought on winter clearance! With a pep in your step, you start searching the garage for your trusty hydration pack, only to find the outdoor fanatic's worst fear: large splotches of dark, disgusting, dangerous mold speckles your hydration bladder.

Do not fear! This article explains how to clean a hydration bladder and streamline the process. In no time, you'll be out on the trail with a dazzling clean hydration system. 

How To Clean a Hydration Bladder

Staying hydrated is paramount to safely enjoy outdoor activities. As dramatic as that sounds, dehydration’s a real concern. The summer of 2023 is slowly concluding, with several states reaching record-high numbers of illnesses or fatalities due to dehydration, illustrating the issue's severity.

Drinking half a liter of water at a steady pace every hour during moderate activity is the typical recommendation. Other factors like the temperature and altitude increase this recommendation even more.

There are many options out there to help you stay hydrated with water bottles of many different materials, sizes, and delivery methods. The choice of most hikers, mountain campers, or bikers, however, is a hydration bladder.

Hiker drinks from hydration bladder during hike

A hydration bladder, or hydration reservoir, is great for outdoor adventures when you are on the go and don’t want to stop to hydrate. A hydration bladder is perfect for activities like biking or hiking. If you’re a cold-weather kind of person, there are also insulated tubes available that protect your hydration system on the slopes and winter trails.

A hydration reservoir fits perfectly in backpacks designed for this purpose, but the bladders also fit in backpacks that have a laptop sleeve. This is a great option if you’re not ready to invest in a pack specific to this purpose. A hose comes out of the bladder and attaches to the sternum strap of a backpack. It is easy to rig the backpack and bladder, so it’s completely hands-free. How cool is that?

Just like any important piece of gear, hydration bladder maintenance and cleaning are necessary to ensure longevity. In this case, it is even more important because a dirty hydration bladder affects your health. If a hydration bladder is not properly cleaned, it’s easy for bacteria to form, and then mold takes hold and sets up residence. As author and spiritual teacher Amit Ray once said, "Cleanliness is a mindset — a positive habit that keeps the body, mind, and environment happy, healthy, simple, neat, and delightful."

Say you just purchased your new hydration bladder, and you’re ready to take it out on your first long bike ride. Hold your horses, partner! It’s in your best interest to clean it first. Just like how when you buy new clothes, you throw them in the washer before wearing them, you should clean the hydration bladder before the first use. You never know what dust or contaminants it came into contact with at the factory or in transit. 

Cleaning Kits

Before getting into the cleaning steps, having the equipment to clean your hydration sleeve is key. A dedicated cleaning kit from the same manufacturer as your hydration reservoir is a great investment. Cleaning kits often come with specific gadgets to help ensure the product cleans and dries efficiently. 

These are the top cleaning kits from hydration bladder manufacturers.

Hydraulics Reservoir Cleaning Kit

by Osprey 

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12/07/2023 04:31 am GMT

Osprey / Hydrapack

Osprey Hydraulics hydration systems partnered with Hydrapack to make their hydration bladders. These bladders are reversible and dishwasher safe, so just load them in the top rack of the dishwasher and let the machine do the work. Sadly, the hose can’t invert, so Hydrapack’s cleaning bundle offers a long cleaning brush to be able to get the hose fully clean.

Hydrant Reservoir Cleaning Kit

by Hydrapak 

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12/06/2023 01:21 am GMT

Bottle Bright is a sister company of Hydrapack. They offer cleaning tabs for their hydration pack. The cleaning bundle comes with twelve of their tabs to deep clean the reservoir. This kit also provides extra bite valves, which is also a great addition.

There is also another kit available through Osprey that offers a slim brush, a drying rack with a hook at the top, and a long hose brush. 

Camelbak Cleaning Brush Kit
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12/07/2023 04:23 am GMT


CamelBak’s kit offers a curved brush to get into the reservoir easily and a Pure Flow tube brush. It's a minimalist kit that gets the job done.

The Crux CamelBak bladders have a circular locking opening, and the Fusion models offer a waterproof zipper opening. There is also a specific drying kit for the Cruz or Antidote models. It is two pieces — one to hang the bag and one to prop the bladder open to ensure the reservoir dries completely. 

Reservoir Dryer

by CamelBak 

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12/07/2023 04:14 am GMT

In addition to these kits, some household items work well to clean your hydration pack. Wedge a plastic clothes hanger into the bladder to prop it open and use another hanger to hang it up. The key is to get the entire bag exposed to clean air. 

Athlete wears hydration bladder during run

Steps To Cleaning a Hydration Reservoir 

Some hydration bladders are dishwasher safe, so before cleaning, check with the manufacturer’s website or the owner’s manual. Remember that when the dishwasher cycle is complete, you need to take it out and hang it to dry. They don’t always fully dry in dishwashers, and residual water breeds mold.


First things first, Run fresh warm water through the hydration bladder components. Be sure the water touches every surface inside the reservoir, hose, and nozzle. Pinch the bite valve to see the water go through the entire system.

While boiling water is typically an excellent sterilization method, it is not recommended for these materials. 


Time to take the components apart. The connections of the gear are a great place for bacteria to find little crevices and multiply.

The three main components of the system are the large water reservoir, the hose, and the bite valve. The hose connects to the bag. Most hoses disconnect, but don’t force it if it doesn't come apart easily. The bite valve detaches from the hose with just a little pressure.

Be aware that the bite valve is a small piece that could fall down the drain easily. It's best to take a cup and add a little bit of dish soap and warm water to make a frothy bath, and then throw the bite valve in for a soak. 


With a deep cleaning agent, such as dish soap, baking soda, or vinegar, use a scrubber to get into the reservoir as much as possible. This is easiest to do with bladders that either fully open at the top or have a circular opening on the side. If your bladder has a small hole, this is where your manufacturer’s cleaning kit really comes in clutch.

Don’t forget the bite valve! Give that a once over with the scrubber to loosen any deposits of unwanted gunk. 

Rinse Again 

Now is a good time to get the bite valve out of its soapy bath. Another soak of warm water with some lemon juice removes any lingering soapy taste. Let that soak for about five to ten minutes. Since you don’t want to taste soap, vinegar, or baking soda, be sure to rinse the bladder and hose well to make sure all of the cleaning agent is gone.

Fill the bladder with water, close it up, and toss it around a bit. It might feel silly, but this shakes loose any hidden deposits of cleaning agents.


Be sure to reassemble the hydration system so it works properly for you on the trail. Connect the hose to the bladder and put the bite valve back on the hose. Run some water through and test it out to make sure you've attached everything well.

Drink a bit of water through it to ensure you’ve rinsed it well enough. Do this before drying so that you don’t find a funky taste out on the trail. If it still tastes weird, rinse it again.

A couple of military soldiers wearing hydration bladders

Dry or Freeze 

Mold is your hydration bladder’s archenemy. It causes nausea, vomiting, or diarrhea if ingested. No one wants to deal with that, especially when the great outdoors awaits you! Avoid exposure altogether to keep anything from getting between you and your fastest known time.

Mold likes to grow in warm, wet places, so the opposite environment is what you’re looking for when storing your equipment. After cleaning your hydration bladder, rig it to dry for a couple of hours. Many of the hydration bladders out there have a hook that works well for this. If it doesn’t come with a hook, some cleaning kits have a drying tool.

Another foolproof idea is to put your hydration pack in the freezer. Mold can’t grow in the tundra of your freezer, so it’s a great place to store it. When you’re ready to use it again, take it out to give it time to thaw, and make sure water is able to flow through the hose before you set out on the trail. Many use freezers to store their gear year-round. If this also works for you, do it! There is no off-season for hydration.

Cleaning Agents

Use a cleaning agent to disinfect the hydration bladder. Water alone can't disinfect these items, as boiling water is not recommended for the lightweight, soft material used for hydration systems.

By selecting one or a combination of the following cleaning agents, you'll be sure to be mold-free.

Dish Soap

The easiest cleaning agent to use is your everyday dish soap. It’s cheap and something that everyone has on their kitchen counter.

Dish soap sanitizes and has grease-fighting properties to break down any funk or residue that could be lurking in the reservoir. Instead of pumping soap directly into the bladder, take a pitcher of warm water, use a small amount of soap, and combine them. This controls the amount of suds in the system and keeps you from having to rinse several times to get the soap fully out of the equipment. Mix it until you get the amount of suds you want, and then pour it into the bladder opening.

The downside of using dish soap is, predictably, the soapy taste, which is why many outdoor enthusiasts reach for a different cleaning agent. 

Baking Soda 

Also known as sodium bicarbonate, baking soda deserves its own fan club. There are so many uses for baking soda beyond its usual partnership with baked goods.

Baking soda weakens the cell walls of bacteria when working in conjunction with an acidic agent like lemon juice or vinegar. Use a tablespoon of baking soda with a teaspoon or two of your chosen acid and mix with a liter of warm water. Add the mixture to the bladder and then scrub with your cleaning kit scrubber, dish scrubber, or even a toothbrush.

A little elbow grease and this everyday kitchen solution is sure to get everything spotless and keep the mold from moving in. 

Ingredients for cleaning hydration bladders at home


Vinegar, specifically white vinegar, is a common cleaning agent. It’s made from acetic acid, which breaks down grime. This makes it easier for you to scrub out any lingering deposits of mold.

Use a teaspoon or two of this superpower cleaning agent with a liter of water. A little of this stuff goes a long way. Combine this with baking soda to make a powerhouse cleaning solution.

Some don’t like to use this cleaning method as the smell lingers and is difficult to get rid of, but it is a natural and proven option. Just rinse it out a few more times.


Bleach is the mother of all cleaning agents but is often intimidating to work with. This option is only recommended if there is pervasive mold in your hydration bladder. Be sure to wear kitchen rubber gloves and clothes that might look better with a little bit of a splashy tie-dyed pattern on them. A little bit goes a long way. A teaspoon diluted with a liter of water is all you need to get the job done.

Check with your specific manufacturer to be sure bleach is safe to use on their product. For example, Gregory is one brand that specifically warns against using bleach.

With this powerful cleaning method, it's recommended to rinse out the hydration system another time or two. 

Cleaning Tablets

Some manufacturers sell cleaning tablets made specifically for their products. There are also generic cleaning tablets available — Bottle Bright is one example. These effervescent tablets react to water and break up any deposits for a sparkling, mold-free clean.

Cleaning tablets are often used for stainless steel water bottles that have that grime or a funky taste that just won’t come out in the dishwasher. Fill the container with warm water, plop the tablet in, and watch it fizz. Let it do its magic for 30 minutes to an hour, then come back and rinse. Sometimes residual fizz remains at the top of the bladder, so following up with a light scrub and, of course, an extra rinse is key if you decide to go this route.

When using a cleaning tablet, be sure to keep the opening of the bladder exposed to the air. The tablet works by releasing gas, so if the bladder is completely closed, it could expand and pop if it's already filled to capacity. While unlikely, it’s not worth risking.

Mountain biker has hydration bladder on back during ride

Denture Tablets

Similar to the cleaning tablets are denture cleaning tablets. Easy to find at most grocery stores, pharmacies, and grandparents’ medicine cabinets, this route is an effective and safe option. As you know, this cleaning agent is for products that go in the mouth, so you know it is safe to clean with. This is a cost-effective method, as there are dozens of tablets in each pack. Use up to three tablets every time you clean, and you’ll be set for quite some time.

The same warning goes for denture tablets as cleaning tablets. Leave an air opening for the gas to escape, as it's an effervescent cleaner. Find many of these packs in a refreshing mint flavor too. 

Lemon Juice

Lemon juice helps reduce the plastic taste that is sometimes present in a hydration bladder. Fill the reservoir about three-quarters of the way to the top. Squeeze juice from a whole lemon or a hefty squeeze of bottled lemon juice into the pack with water, and then freeze the bladder overnight. Take it out the next day to thaw, and then rinse to remove the taste.

Remove the bite valve and soak it in lemon juice mixed with water for an hour or so to help that direct contact taste nice and clean. 

Frequently Asked Questions

  • Can you put ice in your hydration bladder? Definitely! Nothing better than a refreshing cold glass (or bag!) of water on hot days or even temperate days of hard work on the trail. 

  • Can you put hydration additives (such as Liquid IV or Pedialyte) in the bladder? It’s recommended to just have water in the hydration bladder. These additives create deposits that are difficult to clean. 

  • Can you put different liquids like sports drinks or alcohol in the bladder? This is not recommended. Stick to water for this device and put other beverages in water bottles. 

  • The bite valve tastes gross. How can you fix that? Try soaking the bite valve individually with a cleaning agent and scrubbing it. Then soak it in warm water with lemon juice. If the gross taste is still there after you try this method, consider purchasing replacement bite valves from the manufacturer. 

  • You just pulled your hydration bladder out of storage and it has mold all over it. Is it salvageable? Follow the guidelines listed here and use an effervescent cleaner tablet (or two). Scrub after it soaks for a while, and then go step by step to continue cleaning it. Once it’s all clean, store the bladder in a freezer, so mold can’t grow. If you’ve tried this and it’s beyond cleaning and you’re looking to dispose of it, reach out to the manufacturer to see if they have some tips specific to their product. Who knows? They may even have a warranty that covers this kind of issue and can help you with getting a replacement product. 

  • Can you use a household cleaning spray on your hydration bladder? Check the ingredients of the cleaner and check with the manufacturer before using it. Some manufacturers do not recommend bleach and some cleaners contain bleach. It’s likely okay, but using simple cleaning agents is best. Also, diluting the cleaning product with water before putting it into the pack maintains the quality of the bladder. 

Woman drinks from hydration bladder while on the trail

Get Out There and Drink Up the Adventures

While cleaning your gear is the least fun part of outdoor adventure, it is critical for this important piece of equipment. If you neglect to do so, you're putting yourself at risk of consuming unclean water and mold.

Remember, some manufacturers make cleaning kits that are specially made for your hydration bladder. If your manufacturer does not make one, a long brush for the hose is the only piece of cleaning that you may not already have around the house.

Be sure to pair the steps above with one or two of the cleaning agents mentioned to ensure your hydration system stays free of mold to help fuel your next outdoor adventure. Treat your hydration bladder well, and it will take good care of you in return.

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