Nope,

what I meant was when I rotated one the the Jandy three-way valves where the suction side of the pump was drawing water solely from the main drain(isolating the two skimmer returns), there was an apparent lack of flow. The lid on the filter did actually get sucked down a visible amount. Visually, the air appears quite rapidly and achieve some sort of equilibrium at about 2/3 full, and disappears quickly when the valve is returned to it's wide-open position. I used to do this exact thing during the summer when I would clean my skimmer baskets and put new socks on them. It didn't behave this way then.

Completely shutting off the drain side does not cause air to be sucked in through the skimmers. The water level is fine, about 1/2 inch below the overflow drain. My pump and most of the valves are below the water level of the pool, thus air does not typically collect in the lines.