Your tank is right next to an outside wall, so if you don't have an issue with drilling a hole in the wall, that will help a little. Just put a diy carbon filter on the line to "clean" the air a little and to prevent unwanted critters from entering the tube/hose. Right now I'm dosing kalk at night and running a diy chaeto reactor, but the reactor is too small for what I need it to do, so I'm either going add a much lager reservoir for the macro or I'm going to make an ATS? I can make an ATS, but I don't have a lot of space underneath my tank and it requires suspending the ATS above my sump and being able to pull the screen from above to harvest the algae. I may just build a 5-10g box and plumb it next to the sump and use my Kessil H160? I'll be out of work soon, so I'll have time to build stuff.