Calling filter pros!

I'm no pro, but AFAIK those ceramic rings rarely ever need to be replaced. You can rinse them in tank water every once in a while to remove any sludge that's bulit up, but they're basically a permanent fixture in your filter.
 
I agree :D I've been using them in my Fluval 204 for over 2 years and they only every need a quick swish in clean tank water :D :D
 
I third that opinion! I have used ceramic rings and similar media for years with no need for replacement. You can swish in clean water once or twice a year, if necessary. Basically, though, this media is self cleaning in the effect that they will shed themselves of excess bio-film as long as a good current is going through them. Keep clean the mechanical filtration in front of them (which will catch all but the smallest particles) and things should be fine.
 
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