It's a given you can not start with a new filter that has not been cycled for that high bioload in time to save your fish. There are many different filter configurations out there and most if the better ones will cost a lot more then your 55gal tank. If you are on a budget which most of us are, black lava and a makeshift container connected to an air pump and water pump will get you started. I had 60 - 30 gal tanks on a central "wet dry concept filter of 50 gal capacity. But it has to cycle. Supplemented with small individual sponge filters