I was wondering how filtration changes once you pass the 55 gallon mark. I see people using secondary tanks connected to primary tanks, tanks having "overflows," filters/pumps that are down in the cabinet rather than in the tank... could somebody please point me in a direction that explains these systems and when you should or should not implement them into your tank setup? Or do you just start looking at these options when the powerhead & HOT filter systems cease to be powerful enough? Apologize ahead of time for the incompetence.... 
