Reply To: Why does biological filter media need to be replaced?

I think it is all marketing bulls”*t.. If you replace biological media after 3 months you are effectivly starting a new tank four times a year.You then have to worry about no biological media for upto six weeks while your tank cycles.
My best tanks have had the same biological media for over five years with no water quality problems at all, in fact my discus spawn in there weekly ( they eat there eggs but that is another story).
I have a large external filter on this tank that has not been changed/cleaned for over 12 months and my water has never been so stable, it is that good that last time i cleaned the filter i found a large corydoras that had obviously been sucked in as an egg and was a fully formed adult when found :lol:
Remember the best aquarists keep water not fish……get the water right and you’ll find the hobby really easy.