Plumbing and Piping - Air Gap in Basement for Water Filter

I am installing a fluoride water filter in my basement. I don't have a drain in the basement. The electronic control unit on the filter has a ½” drain line that I need to connect to the sewer. In the basement room where the filter is located there is a 3” drain line that runs horizontally along the wall, about 7’ off the floor. It connects to the sewer line, about 40' away, then exits the house.

Can I connect the ½” drain line directly to the sewer line if I use a Gap-A-Flo (http://www.airgap.com/gapAflo.htm) Flo air gap?

OR

Could I make a “P” trap and connect it to the sewer line and run the ½” drain line into it?

Yes - you can cut fitting into drain line then install 1 1/2" P trap with 20" stand pipe and drop your drain line into it no more then 10" into stand pipe.