Nice App. with a major bug in this version!
Actually the animation of the fishes could be a little more natural - but overall the composition of colors and shapes of the reef and fishes is beautiful to watch. I am using an iMac version 13.1 i5-4core 2.7Ghz with OS X 10.8.3 (latest version) and the application does not seem to need much resources: it works fine and stable. The only thing that is really annoying is a bug within the fish-composition-list: fishes can be removed from the list but once removed - no fishes readded to the list are stored and reactivated in the sreen saver. If you reopen the dialog to look at the fishes in the list: the new added fishes were not stored as already mentioned. In that context multiple choice of the same fish in the list is not possible as well. This is a major bug so I hope it will be fixed soon.
Chrisalin about
Aquarium Screensaver, v1.2