I am switching to a Fluval 306 canister filter for my 55 gallon freshwater community tank after the motor failed for the second time in my Aquatech 30-60 filter that hangs over the side of the tank. Do I need to somehow incorporate the biological filtration pads (the ones you don't replace) from the old filter into the new canister filter? There are fish and plants that have been in there from 3 years (oldest) to about a week. Any advice would be much appreciated. I'm still learning and not totally sure what I'm doing.