Hi, i was wondering if anyone could help me with an issue I'm having. I am curious as to when to change out the biomedia cartridge and the bio-foam in some power filters. I don't want to kill the bacteria colonization and stuff. I tried reading other sites about how you just rinse it in aquarium water or something but i have no idea what they are talking about. can someone also walk to through the steps whether to buy brand new bio-media and bio-foam or "rinsing" it or w/e. Thank you.