Hi, I am wondering how much media I could remove from my external filter (305) before it kicks off a mini-cycle, my theory is if I took a maximum of a third of each media out and put it in a smaller external (105) there shouldn't be too much interruption on the original bacteria colony and theoretically I would also have a virtually cycled new filter....
The chemistry of cycling etc it isn't my strong point so can someone shout if I'm barking up the wrong tree please before I undo the months of work getting my main tank matured.

The chemistry of cycling etc it isn't my strong point so can someone shout if I'm barking up the wrong tree please before I undo the months of work getting my main tank matured.