I was wondering whats the better Power Filter?? The Emperor 400 or the Aqua clear 500? The AC 500 puts out more gph but the Emp. 400 has the bio wheels... Whats the better filter? I plan on putting 3 of them on a 180 gallon I am picking when it comes in at the end of the month. Which one works better and which one needs less maitnance? I was also looking at the possibility of the Kent Marine Bio Rocker 300 standard kit?? It says its designed for tanks up to 500 gallons? But only pumps 500-900 gph??? Would this be enough of a wet/dry system for a 180? I have no idea how one of these wet/dry filters work...Would I have to drill my tank? Sorry I know alot of questions but I just want to make sure I get the right stuff the first time, I don't want to rebuy stuff! Thanks for all the help.... Jake