changing filter media

[Sesos]

I have above water filter that uses ceramic media on top of a poly filter. How frequently should I change the poly filter? It's currently pretty dirty after two months but I guess it's supposed to be (it's a filter after all).

 

[Allivymar]

I change mine when its clogged. If water flows thru it easily, I prob wouldn't worry. But if its slowed down, I'd change.

 

[loganj]

I usually change the filter cartridges on my FW tanks at least once a month. It depends on the size of the filter and the bioload in the tank. As Allivymar stated, when the water flow slows through the filter, it's definitely time to change it.