We recommend backwashing your filter when you flow rate begins to diminish, before prolonged storage, and when you are ready to start using your filter again. Backwashing your filter after storage is a great way to re-wet the filters and restore the flow rate before use.

Flow rates vary depending on how clean the filter is and how well you cleaned the filter. Altitude also affects the flow rates (the higher you go the slower the flow. Also, the PointZEROTWO™ filter flows much slower that the Point ONE.

Your Filter is safe from freezing temperatures if it has never been wetted.
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After initial wetting
While there is no definitive way to tell if a filter has been damaged due to freezing, Sawyer recommends replacing your filter if you suspect that it has been frozen.

During trips
If you are in freezing temperatures, we recommend that you store your filter in your pocket or close to your person so that your body heat can prevent freezing. THERE IS NO WARRANTY FOR A FROZEN FILTER.

The Sawyer filter removes taste that comes from bacteria, dirt, and green matter.

Chemicals
The Sawyer filter does NOT remove iron, sulfur, other chemicals, or simple compounds. Taste can be masked by using flavor additives like Gatorade or crystal light (filter needs to be cleaned immediately after using them).

Heavy Metals
The standard Sawyer filters are not made with charcoal. While other portable filters have charcoal, they lack in amount of media and adequate dwell time. Therefore, they only remove small amounts of heavy metals, pesticides, etc. For the removal of heavy metals, see our Select Series S3.

We have independent lab tests using EPA protocols and information about our filters and their warranties available on our Resources Page.