I just set up my freashwater aquarium about 2 months ago. I am currently using a power filter but a lot of people are telling me to go to an under gravel system. I just am not sure if this is nessesary. and if I do decide to do this how should I go about it. I really dont want to start all over and waste the good water in my tank or stress the fish. I have a 55 gallon with 2 rainbow, 5 barbs, 2 blue dwarf Gurami, and 3 flame Gurami.