Filling an Osprey water bladder is easy. Osprey is known for making durable, easy-to-use packs that hold enough water to keep you hydrated all day. But you will have to refill them! Make sure you follow the right steps and check for leaks before you put the bladder into your backpack.

Easy Steps to Filling an Osprey Water Bladder

  1. Slide the locking clasp, the “Slide-Seal” open.
  2. Unfold the spout or “Pour Shield.”
  3. Pinch the top to open the bladder.
  4. Fill with fresh, filtered water. The handle helps with stabilization while it fills.
  5. Slide the locking clasp back into place.
  6. Hold the bag upside down to check for leaks.
  7. Take a small drink from it to remove air from the pack while it is upside down.
  8. Put right side up and secure to the inside of the pack
  9. Test with small drink before you go on your outing.

Filling the bag is as easy as that!

What Kind of Beverage Can You Put in an Osprey Bladder?

You can fill an Osprey bladder with anything you like: water, sports drinks and even wine (in a pinch). Just be prepared to clean it very well if you use anything but water.

Can You Filter Water in an Osprey Water Bladder?

Yes, you can fill an Osprey bladder with a water filter. Just fill it as directed above and then fill the hose of the water filter with water from your pack. Turn on the filter and let it fill itself.

Osprey Bladder Maintenance

It is more difficult to clean an Osprey bladder than most hydration packs because the hose cannot be removed. Instead, fill an Osprey bladder with clean water and turn it upside down to flush the tube.

Always fill an Osprey bladder before flushing even if you aren’t planning to use it for a while because storing partially full bladders can lead to mold growth over time. If you suspect that your bladder has gotten moldy, use a cleaning tablet in the bladder and rinse very well.

If your bladder is visibly moldy, you can even use a mild, foodsafe solution of bleach water and let that soak for a short time. Then rinse very well and air dry completely

Once clean, flush and fill at least once a month even if it is being stored in a cool dry place.

How Often to Replace Bite Valve on Water Bladder?

Most Osprey bladders come with a standard bite valve that can be replaced when it wears out. It’s important to replace your bite valve at least once a year or more often if it shows signs of wear. The best way to check is by looking closely at the opening and where you place your mouth. If there is any damage to the opening, the valve should be replaced.

How to Replace a Bite Valve on an Osprey Bladder

To replace the bite valve, push the two buttons in on either side of the tube to release it from the bladder.

Slide out the old hose and attach a new hose by pushing both sides in until they click into place. Do not over twist or you may damage any small watertight seals.

Water From My Osprey Bladder Tastes Like Plastic. Is This Normal?

Wash your new Osprey bladder in mild soapy water and rinse very well. Fill with fresh, filtered water. If you detect a plastic taste from the new bladder, squeeze a few drops of lemon juice into the water and freeze the bladder overnight.

In the morning let the bladder thaw out, then rinse the lemony water out, rinse and refill. The taste should be gone.

Is It Hard to Clean an Osprey Water Bladder?

No, but it is imperative that you do so. See the cleaning instructions in your pack’s manual or online. Follow the manufacturer’s directions to keep your bladder working well for years to come.

Will My Osprey Water Bladder Freeze?

Yes, an Osprey hydration pack bladder will freeze if not properly taken care of. It won’t get damaged unless the bladder is full. In that case, water can expand and damage the bladder.


Filling and caring for an Osprey Water Bladder is remarkably easy. Follow the directions, maintain and clean as needed, and your bladder with be with you for many adventures to come!