I'm already running opposite schedule fuge with chaeto. Skimmer line to outside I don't feel comfortable drilling a hole into the side of the house for.
CO2 scrubber will work for you as long as you keep changing the media. I live in an apartment and my tank is in a room with no windows. I've tried all the temp fixes the 2 things that have worked the best so far are leaving the windows open when I can and oversize slightly on my skimmer. With those 2 my ph range is 8.2 day and 7.8 overnight. CO2 scrubber overtime was too much $$ and the airline was not an option the nearest window is about 20ft away.