I have had two freshwater aquariums for several years, one 29 gallon with a HOB
Fluval C4 filter and 38 gallon with two Fluval C3 filters. The 29 gallon "sprung a leak" ... and rather than try to repair it, I put the all the fish in the from the 29 gallon into the 38 gallon tank ... and put the Fluval C4 filter on the 38 gallon as well. Thus all three filters are running on the 38 gallon tank therefore keeping the BB in the C4 in tact for when I return it to my new Aqueon 29 gallon tank
I just filled the new 29 gallon with tap water and plan to let it sit a few days before moving fish. Of course I will do everything gradually and make certain the temperature and so forth are equal in both tanks when I move the fish. I plan to put the fish in a five gallon bucket half full of "old aquarium water" and gradually siphon some "new" water into the bucket, let them get used to it, and then pour water and fish from the bucket into the new tank.
It seems to me that if I move the fish and the C4 filter simultaneously back to the 29 gallon tank, there should be be no reason to "cycle" the new tank and do a bunch of water testing and water changes unless the water turns cloudy or some such obvious problem.
Can anyone see any problem with my approach or analysis? Any comments or suggestions would be appreciated.