The way you have it set up there the height of the bend with the airline will be will be the high point of the water. If you have to have that bend in there than you need to remove the airline and make it water tight, than fill it with water so that it siphons out. The issue I would see with it though is that you always have to make sure the water level doesn’t get too low to get air inside the line and up in that bend. If it does you would have to wait until the water level gets up to that bend and creates a siphon again.