Sounds like your having a bacteria bloom. Vodka is a carbon source that feeds nitrifying bacteria, however it also feeds and fuels other bacteria in the system not limited to but including cyanobacteria.
Your skimmer may not be keeping up but the problem lies in the vodka. Of course upgrading your skimmer can never hurt your tank
29g Mixed Reef, 150w 14k Phoenix MH w/ Moonlights, Reef Octopus BH1000 HOB Skimmer, Ecotech Vortech MP10es, ReefKeeper Lite (Plus), PH Probe, Temp Probe, ATO, Carbon/GFO Reactor.