Hi. First I would say if you can run 11" of water in your sump I would strongly consider the 3130/2 which has just been redesigned and I really like the new design a great deal. It is a much cleaner neater design, even quieter than before- basically now completely silent, of course I think our skimmers have always been the quitest available but an even larger silencer and using the new heavy quage Silicon airline like you see on EuroReef skimmers has reduced the noise even further. We also are using a new venturi which we conservatively say boosts performance 20% though most of our tests show something like 40% is more typical. The 230/3 will see similar improvements but we have found some bugs that need to be worked out as the more compact design means the greater force of the new venturi and more airbubbles mean more bubbles get back to the pump and over time the pump can choke on it's own bubble production, it won't stop, but it does get noisy. So, it isn't quite ready yet.
230/3
Pros-
Very Quiet,
Very Compact,
Plankton Safe,
Very Low Energy Consumption- 21W
Delivered Complete with pump,
Very reliable and consistent performance
Cons-
Plankton Safe feature means weaker performance,
Poor at particulate removal,
Requires constant water level
AquaC
Pros-
About 50% more powerful overall in my experience,
Great at particulate removal,
Fairly reliable performance, does require more tweaking than a Tunze in my experience,
More tolerant of water level fluctuation
Cons
Slightly Larger,
Best pump will use more than twice as much electricity and produce more heat,
Kills plankton that enter skimmer
Louder but not a loud skimmer really
