(10-01-2014, 03:04 AM)KShuk Wrote: Today makes about a month since I started cycling. When I first put in a new filter it said to change it every month. Should I be doing this? Isn't the bacteria on that filter? Should I wait until cycling is complete? I haven't taken my readings today but yesterday ammonia was still between 2 and 4 and nitrate at 5.
Never change your filter media. It will completely remove all the beneficial bacteria and restart the cycling from day one.
What needs to be changed is the activated carbon (if) your filter has it. As the matter of fact, activated carbon is really not needed unless you are trying to remove medication from the water after treating the fish for diseases or parasites. I had activated carbon in my canister filter as one of the stock filter media when it arrived. I removed it after its time was up, and I never added new activated carbon as there is no need to. No problem ever occurred.
For the rest of the filter media, do not ever change them unless they are falling apart. If your filter is slowing down due to debris in the filter media, you only need to wash it gently in a bucket of old tank water or treated tap water to avoid damage the bacteria colony on it.
Have you been adding ammonia? During my fishless cycling, the nitrate shot up really high fairly quick once it started to appear.