i run the fx5 and i also have a koralia 4 and koralia 3 for extra flow....the tank is a juwel 400 which comes with a ehiem internal filter which i run without the sponges....i find the fx5 does a great job both with its high flow rate and it keeps the tank crystal clear....yoimb0b;1995156; said:are you only running live rock and an fx5? looks good.