I am thinking about buying a 400-500G aquarium and I was wondering what type of filteration I should buy. I want to buy it online from a place like BigAlsOnline. The aquarium will be stocked with central/south american cichlids such as managuense, midas, and a buttikoferi. Maybe an arowana, red tail catfish, stuff like that...Thanks a lot for the recommendation. I really would like to over filter the aquarium to keep it in the best shape as possible. I would like to stay away from HOB's, and cannisters. I'm thinking some type of sump filter, but does a sump provide enough mechanical filteration? I really would only like one filter. Or, two sumps would be okay. What type of pumps would I need to return the water to the aquarium? Thanks again a lot...