Ok...so after everybody's advice and the amount of people who responded to my poll, I am going with the Aquaclear HOB. Originally I was going to get a 50 and run it alongside my Whisper 30. However, I forgot that I do not have access to the right side(if facing tank) of my tank due to a shelf directly above it. Can the filters be placed right next to each other on the left side or should they be at opposite ends. If they must be at opposite ends, can I get away with an aquaclear 50 or should I bump up to a 70? Thanks again so much and sorry for the inundation of newbie questions....just want to make sure I get everything right.