I dont have any, but I am considering getting one. Is it possible to over filter? I have a 55g right now, plan to get a 75 or a 90 pretty soon. Would an FX5 be too much for that? Eventually I plan to go with a bigger tank, 125+, but I am thinking by getting the filter now I will be ahead of the game...or am I just better getting something sized for my tank? I have heard nothing but good things about the FX5's...