I have a cartage filter with carbon.

[pettygil]

I have a cartage filter with carbon. I just bought AquaClear 70 Foam Filter Inserts, Aquarium Filter Replacement Media, 3-Pack, A1396 .
Do I change right away to the sponge, or do I keep my cartage in, and then add the sponge? and if so, for how long?

 

[Colin_T]

Add one or more sponges to the filter but keep the old filter pads in the filter too. In 2 months time you can remove the old filter pads and throw them away, leaving just the sponges.