Thanks for the help. You are correct in assuming that the 3rd drawer has the bio balls. I did fear that i would have to remove the drawer completely to add holes. My only issue with that is it's already fairly riddled with them. I had suggested a side hole to try improve the air flow and help the water pull through the filter but I'm guessing that just isn't going to work the way i want it to.
Is the filter sock over the intake of the pumps a bad idea? They are only on about 3/10 power so I could really bump it up to compensate for the restriction that the sock would cause.
What's the idea with the lava rock all about? Does it act the same as the bio balls or does it serve another purpose?