I have pretty much settled on the reefpack as the skimmer for the 120 gallon I am beginning to set up. I am really sold on the hang on the inside design with surface skimming and built in top off system. However, I really would like a little more skimming capacity. I realize that 120 gallons is within the specifications for the 500, but this is going to be an octopus tank and if he inks, I want to be able to get it removed as soon as possible. If the reefpack cannot be upgraded/upsized, does anybody have any suggestions? I do not have a sump and would prefer not to drill the tank.