Corey, as time goes on you should have to use less and less vodka. You're over-dosing. Trying a product made for reefs might be a better idea. The Brightwell Aquatics Microbacter7 (MB7) is quite reasonably priced. I just started using it in my reef along with their BioFuel to see what happens.
Looks like you could use a bit more flow in your tank too...or adjust the powerheads.