the bulkhead on the bottom right of the picture is closed off ( from another design). it actually drains from underneath theres about a 1 inch gap of air under the screen water runs off the sides and drips threw

If i can find the venturi part to the maxijet i was going to put that on so air bubbles would poor out on to the screen.

I've noticed when the tank water evaporates and the pump starts sucking in air it turns the surface of the screen soapy.