Oldfishlady gave me this great advice.
Originally Posted by Oldfishlady
...On your filter media-give it a swish/rinse in old tank water or dechlorinated water a couple of time a month and when the water flow slows to get the big pieces of gunk off to maintain water flow....you want it to look dirty...this is the good bacteria-it also need good water flow and oxygenated water to colonize on the surface area of the filter media...
I just wanted to make sure doing this is okay. Also, should I ever replace my filter cartridge? I have an Aqueon 2.5 gal Minibow.\