Filter usage will depend on frequency of use and the water used in your Canopy. The best way to tell if your filter should be replaced is by looking and feeling. If your filter has turned crusty, hardened, discolored (black, brown, orange, other), then its time to replace your filter. Generally, we recommend to replace your filter every 5-7 weeks to ensure Canopy is performing optimally. Canopy's filter light will come on to help remind you to change your filter.