Ah, ok. I thought you were trying the vodka on a more permanent basis, that's why I suggested you ditch the Zeo. One or the other doesn't really matter, just not both!
I've run Zeo and GFO together with no issues, but I understand if you ramp down on the GFO over a few months that the Zeo will work better. I think it's because the PO4 acts as food for certain parts of the Zeo system (that's an educated guess though).