i use black diamond carbon, but switching to ESV carbon in a few days, and was just curious how often you replace the carbon? weekly? monthly? people told me every few weeks they replace it but usually the containers says 4-6 months? whats your opinion on this?
how often and how much all depends on your water quality...it was recommended to me by a few well know aquarists to change it every thirty days at the rate of one cup per one hundred gallons more often if something is wrong....like after a red bug treatment etc... I use Black Diamond and been doing it this way for years...