sugar work the same way as vodka. u need a gd skimmer for this method to work. i was using vodka but seem like no effect. then i switch to sugar n notice my NO3 dropping within 2 wks. but for dosing, u have to increase ur dosage slowly. i started with 1/2 tsp for my 450L tank. started to c no3 drop when i increase to 2 tsp after a couple of days. but dose with care for both vodka n sugar. it can reduce ur NO3 but at the same time if u overdose, it can crash ur system. right now i using denitrator so stopped using dosing liao.