When should I replace my Grayl filter?

As you use your Grayl purifier, the 'press time' will slowly increase with use. When 'press time' reaches ~25 seconds (or three years have elapsed since first use), it is time to replace your cartridge. Note: Especially cold water may take longer to press and does not indicate your cartridge needs to be replaced.

If your Grayl is feeling especially hard to push, it may have filled with sediment and contaminants.

The lifespan of the Purifier Cartridge varies with the quality of the water source; the clearer, the better. High levels of silt or sediment will shorten the lifespan of the cartridge and make it hard to push. When using clear water, the cartridge will be effective for ~300 cycles (40gal / 150L) – about three uses per day for three months. As cartridge life nears its endpoint, press time increases. When press time approximately doubles to ~30 seconds, it's time to replace your cartridge.