Activated carbon in an aquarium filter will typically last about a month, however, this can vary based on factors such as tank size, bioload (number of fish and waste products), and water conditions. You can replace activated carbon every 1-2 weeks, but activated carbon can be effective for up to a month.
Factors that affect lifespan:
Bioload:
Tanks with a high bioload will exhaust the carbon's ability to absorb contaminants more quickly.
Water quality:
If the water contains a lot of tannins or other impurities, the carbon will become saturated more quickly.
Tank size:
Larger tanks require more carbon to maintain good water quality, so it may need to be replaced more often.
Signs it's time to replace:
Water appearance:
If your water is turning yellow or cloudy, this is a sign that the carbon is no longer filtering effectively.
Odors:
If you notice any unpleasant odors in your tank, this could be a sign that the carbon is saturated.
Water quality testing:
If you measure the water quality and see elevated levels of the contaminants that the carbon is supposed to remove, then it's time to replace the carbon.
