Microbubbles. How can I stop them from reaching the display tank?

[T-5unsystem]

Does this have plumbing in the bottom of the drain bulkheads so the output is under water not "splashing" on the top of the water? Also seems like cutting out the slots and making it a full hole would help the water "sheet" down the acrylic rather than spill out in streams thereby reducing introduction of air since it would slide down the acrylic.