Learning the right way to fill your CamelBak bladder from the beginning will save you time and could prevent you from drinking moldy water or damaging your reservoir.
And the good news is, it’s actually a pretty simple process.
To fill a CamelBak bladder:
- Remove the reservoir from the pack.
- Open the cap or zipper.
- Do a quick check for mold and mildew.
- Fill the reservoir no more than 90% full.
- Seal the bladder (keeping out the air).
- Return it to your pack.
Filling a CamelBak bladder should only take a couple of minutes once you get the hang of it.
Step 1: Remove The Bladder From The Pack
Before you fill your CamelBak bladder, the reservoir needs to be removed from the backpack.
With most models, it’s pretty easy. Just unzip the bladder pocket, slide the delivery tube out of the slot above the shoulder, and pull the bladder out by its top seam, not by the handle.
Once your bladder is out, place it lid-side or zipper-side up on a flat surface.
Step 2: Open The Reservoir
Once your bladder’s out, it’s time to open the reservoir.
Crux reservoirs seal using a basic twist-off cap — turn it gently counterclockwise to open.
Fusion reservoirs seal using a watertight TRU Zip zipper — slide the zipper across the tracks to open.
If for whatever reason the lid or zipper aren’t opening easily, check out my deep dive on troubleshooting and fixing a stuck CamelBak lid.
Step 3: Spot Check For Mold And Clean The Bladder If Needed
Before filling your bladder, it’s a good idea to make sure that the reservoir and tube are both clean and mold-free.
Look the bladder over for signs of mold, normally small dark spots found in patches.
Pay particular attention to the seams in the reservoir, the inside of the mouthpiece, and the threads of the cap, which are the most common places for mold to grow.
Also give the interior of your bladder a quick smell test. You’ll often smell mold and mildew well before you can see them.
If you spot mold or notice a musty, earthy odor, treat your CamelBak for mold before using it.
Step 4: Fill With Water
Fill the reservoir with whatever you plan to drink.
I recommend only using your hydration pack for water, since CamelBaks tend to absorb flavor and, if you don’t clean the reservoir well enough afterward, mold is more likely.
But ultimately it’s your call.
Also be mindful of how much you’re filling your reservoir. Even though CamelBaks are pretty durable, filling to maximum capacity every time puts a lot of unnecessary strain on the bladder.
If you need to carry as much water as possible, aim for about 90% full.
If you don’t think you’re going to need as much, underfilling the bladder is no problem. It’ll save you the extra weight and help lengthen your bladder’s lifespan.
Step 5: Seal The Reservoir And Remove Excess Air
Close the reservoir, squeezing out as much excess air as possible.
Leaving too much air in the bladder will make your water slosh around as you move and make the last few inches of water difficult to pull through the tube.
While most excess air can be squeezed out, you’ll still need to remove the rest once the bladder is sealed.
Flip it upside down so the pocket of air trapped inside is near the QuickLink port, then suck any remaining air out through the delivery tube.
Step 6: Place The Bladder Back In The Pack
Return the bladder to the pack by holding it by its top seam and lowering it into the bladder pocket.
Thread the tube through the opening near the right shoulder, attach the bladder to the pack using the fabric loop, zip up the bladder pocket, and you’re good to go.