Hello everyone - On both of my tanks, I have HOB filters that came in kits with the tanks. My question is: What is it about Biowheel filters and cannister filters that make them so much more expensive and better to use? Are HOB filters considered a bad choice? They seem to be doing their jobs just fine on the tanks that i have. Also, Does tank size difference make a difference in the type of filter you use (I know that with larger size tanks, you should have more than one filter)??? Thanks All!