I don't think I'd
ever run a drain line on a skimmer cup without a well-proven auto shutoff. Anyone remember
Steve Weast's 850g tank? It crashed because his skimmer, equipped with a drain line that simply emptied into the sewer, freaked and drained his tank down. The ATO kept up and his salinity dropped. Considering that things like switching foods or rearranging rock can make a skimmer run away like that, I wouldn't be able to sleep at night with a waste drain on a skimmer unless I knew for sure that it would shut things down if the skimmer ran away.
Back on topic - nice skimmer.

I must say that the Reef Octopus has a vast range of skimmer options. Seems like you can get any needlewheel-based configuration on the planet from them. Pick a tank size and they have at least 3 or 4 different model that apply. How did you choose this over their other products?