I'm planning on getting a new filter for one of my 10 gal. tanks, because when I got the filter I thought my tank was a 15 gal. instead of 10 (I know, stupid), so now I've had this giant over-sized filter taking up more space than needed in the tank. (It's a Tetra Whisper 20i)
I have a Tetra Whisper 10i for my other 10 gallon tank, and it works & fits perfectly, but I don't want to get a new filter and lose all the good bacteria from my old one.
Can I take out the cartridge in my current filter, and put it behind the cartridge in my new one, so the bacteria can form in the newer one? Or is there a better way to do it?
Help is much appreciated!