If you decide to run BP and your nitrates is up there. You can do stop for a few days and run maybe 3/4 dosage of BP to begin with.
But a few question need to answer. How long have you been dosing Vodka and what is your nitrates and Phos level? My main concern here is if your vodka dosing is working for you and nitrates is now. B-Pellets take longer before they fully populated. If your nitrates is low, you might need to feed more often to bring up the nitrates to feed the pellets. While vodka will have big effects on phosphate, B-pellets have very little in phos reduction.