Some people believe activated carbon can last for months, while others believe it only lasts a few days.
The truth is, the lifespan of activated carbon depends on a lot of different factors.
Different brands use different temperatures to charge the carbon, which can make it last longer or shorter than others. Typically, it will last between 2 and 4 weeks.
The dirtier the water in your aquarium, the shorter the lifespan of the activated carbon. This also happens when you have corals or microalgae in your aquarium, as they are constantly releasing biochemicals into the water. Activated carbon helps you remove these biochemicals by absorbing them.
Even though activated carbon is one of the most absorbent filter media, the more it absorbs, the faster those tiny pores become clogged. Eventually, so many pores are clogged that it can no longer absorb anything.
When this happens, the activated carbon loses its charge.
You should replace your activated carbon every 2 to 4 weeks, depending on the bioload in your aquarium. For example, if you have turtles, you'll need to replace it weekly.
