My longest aquarium has been running for 5 months now and fully cycled and water stats are spot on, I have a 25 litre aquarium with 1 betta in, if I take some filter media from my established aquarium will it cause any problems and has it been running long enough to be taking media from it, also if I did take media would it be ok to cut the sponges to the size of the filter as they are totally different sizes.