How often should i change the carbon in my fluval 204

Question

I have a 50 gallon tank

Answer 1

I have the exact same filter for my 30 gallon. I usually change it about once every 6 months, but depending on the amount of fish you have, it might be earlier or later.

Answer 2

I have a Fluval 405. I switch the media monthly. So if I do carbon, I don't change any of the other media so the beneficial bacteria doesn't get taken out.