Looks like you found the answer! Top skimmer an lower intake, works great you only need to adjust it once or so a week, takes two seconds. Only way it would suck in straight air is when the lower intake is completely clogged and your water level is so low that the skimmer hits it's lower limit, very hard to do unless your on vacation and no one is there to stop it.Hello mott, thanks for the tip. I like that idea.
Does it run in parallel to the main intake of your filter or does that become the main intake? Kind of hard to tell from the pictures. Is it possible for it to suck air if the water level drops too low?