How to Remove Calcium Buildup in your Sawyer Filter

Removing Calcium Buildup

The Sawyer water filter should be able to filter 1 liter of water in about a minute. If your Sawyer filter is flowing much slower and backwashing doesn’t increase the flow rate, you might have calcium buildup. Having calcium buildup is a very common problem after months of backcountry use. Luckily, it’s easy to remove the calcium buildup following these two steps.

1. Soak your Sawyer water filter in vinegar for 30 minutes

Using a sealable bag reduces the amount of vinegar needed to soak the filter.

2. Flush the water filter with warm to hot clean water

Repeat steps 1 and 2 if needed.


After a few months of backpacking it is common for the Sawyer Squeeze water filter to experience calcium buildup. This calcium buildup can easily cut your water flow rate in half. So before you replace your slow flowing Sawyer Squeeze I recommend treating your filter with vinegar to remove any calcium buildup. The Sawyer Squeeze water filter is designed to last over 6 months (up to 100,000 gallons of water) with proper maintenance.