So I've set up a new 240L tank recently. It has a Fluval 306 external filter. I also have a mature 125L tank running a Fluval 206 canister filter. I've moved all the fish from the 125L tank into the 240L but have taken two of the sponge pads along with a handful of ceramics from the mature tank and put them into the new tank filter. Will this be enough to kick start the cycling process or should I have added more of the filter media?
Fish that have been moved:
11 Electric blue Acara's (very small 1" in size) 4 small platies Bristlenose Plec Bamboo Shrimp 1 Guppy 4 Honey Gourami 4 Black Phantom Tetra
Re: Cycling a new tank with mature filter media?
If you move *all* of the filter media from the 125L's Fluval 206 into the 240L's Fluval 306, then the 240L's Fluval 306 will be instantly cycled and able to support all of the fish that were originally in the 125L tank.
If you were planning to stock the 125L tank in due course, you could then either run a fishless cycle on it by putting new media in it (easiest all round) OR you could retain some of the mature filter media to kickstart the process in the 125L tank - up to 30% of that would probably be safe enough to do so (but you'd need to keep a close monitor of water quality daily in the 240L for the next month or so to ensure that the mature filter media having dropped to 70% is able to support the fish in there).