Compliments of Tom/TMZ:
Vinegar which is 95% water is 8x more dilute than 80 proof vodka . When calculating a dose, 1 ml of vokda equals 8 mls of vinegar. You can use the vodka dosing start up guidelines for vinegar if you mulitply them by 8 .
Cost isn't much different. Bartons vodka is $14 for 1.75 liters ; vinegar about $3 per gallon. (3.9 liters).In terms of carbon content and equivalent dosing amounts 1.75 x8 =14 liters of vodka or roughly3.6 gallons of vodka. So @ $3 per gallon , it's approximately $11 worth of vinegar to equal $14 of vodka.
They can both go in a kalk reservoir together or separately. Bacteria will begin to consume either of them when they are diluted in regular water but not in the high ph kalk water.Off the shelf the low ph in vinegar is outside the tolerable range for the bacteria and the alcohol in the vodka stops them but when either of them is heavily diluted in plain water the change in environment favors the bacteria.
Vinegar in a kalk solution will also allow more calcium hdroxide to go into solution as much as 2.72 tsps per gallon with a dose of 48ml vinegar to 1 gallon of top off water vs 2 tsps per gallon. Adding more vinegar beyonde that has no additional effect on solubility This allows a higher dose of kalk than otherwise. Vodka does not increase the amount of kalk that can be held in solution.
Vinegar is fine,perhaps even a better source for carbon than vodka , but needs to be dosed slowly or in relatively small amounts preferably during photosynthesis. It brings in CO2 which drops ph quickly when dosed in bulk.
Vodka reduces ph from the bacterial activity as well and over time and equivalent amount of carbon from vinegar or vodka would even out but vodka is a step or two behind vinegar in degradation and CO2 formation so it takes it's time and the change in ph is not precipitous allowing time for equilration with the surrounding air along the way.. Since I prefer to dose it in bulk , a high proportion of vodka works for me
Just vodka may cause some cyano based on anecdotal observations .
Using some vinegar or all vinegar seems to more effectively limit cyano but that's all anecdotal at this point.
Tom