I started with a gallon of tank water, added Fritz F/2 media at half strength and half a salifert scoop of crushed fish flake then bubbled the result for a day or two to get the water nutrients semi-stable.
Starting nutrient level: 51ppm NO3, 2.61ppm PO4
I then split it into 3 bottles that I bubbled continuously in the dark. Control got nothing, 2nd got double recommended doses of Waste Away, and the 3rd bottle got vodka that was 1/6th of the WA (approximately carbon equivalent based on earlier O2 consumption measurements)
So here's what it looks like
Stars indicate which days WA and Vodka were added.
The control became more Carbon Limited around day 5 and nutrient reduction slowed a lot.
The Waste Away and Vodka treatments behaved really similarly to each other. In Phosphate, after day 6, they stayed within about one test error of each other, though the WA was almost always the lower one.
In nitrate, the difference was a little more clear - WA was consistently lower and became (and stayed) zero/undetectable on days 11&12.