I was thinking the same thing also about the skimmer returning water and what not. I think I will try and do away with the filters all together and run the skimmer and a couple power heads. Might end up using the filter just to move water around in my bag that I cure the rock in. Thanks a ton for the infoOnce your rocks in and sand they will house the bacteria the filter is. The filter will be more or less your preference. The skimmer and rock/sand will be your main filtration. If u have strong flow from your power heads they will break the surface water for agitation. Personally I would not have the filter but to each there own. It can help remove the bigger partical from the water but it is just one more thing to maintain. IMO