Are there any good reasons to stick with Vodka rather than vinegar at this point? Sounds like Vinegar is preferred primarily due to the fact that it's less likely to feed cyano.
Before we reinstate the 18th Amendment to the US Constitution, I'll try to offer some comments in favor of keeping vodka around as a useful but not necessarily a better option than vinegar.
There is a perception by many based on anecdotal accounts that vinegar dosing is less likely to encourage cyano . There really isn't anything more to go on in terms of which is better for a reef tank: vodka, vinegar or both. Ethanol oxidizes to acetic acid and both are down the cascade of anaerobic bacterial digestive activity.
In my experience they are both beneficial to a mixed reef tank in terms of nutreint management(low PO4 and low NO3), proliferation of sponges feather dusters and presumably other food web members and animal health including good growth and color in a variety of corals. Both are unlike, sugar which definitely caused problems for my corals even in very small amounts. So. I stay away from carbohydrates(polymers) and sugars(monomers) but have no trouble with vodka and vinegar.
I started dosing vodka over 3 years ago and have done so at a moderate dose continuously. After a few weeks at the start, some small patches of cyano appeared here and there; not much but I'm obsessive.
Several savy folks claimed success with vinegar vs cyano in lieu of vodka; so, I dropped the vodka dose by 25% and replaced it with an equivalent amount of vinegar. The cyano disappeared after a week. Maybe coincidence;maybe not. Eager to simplify to one source , I dropped another 25% of the vodka and repalced it with and eqivalent amount of vinegar a week later. The cayno returned.Maybe coincidence; maybe not. In any case I went back to the roughly 75 vodka / 25 vinegar mix and almost no cyano occurs ; none in the display and frag tanks with only an occasional small bit in the chaeto refugium.
There are differences in how you can dose vodka and vinegar in view of long and short term ph effects which may be important in individual situations.
Vinegar adds CO2 quickly and causes precipitous ph drops when bolus dosed . The dose should be spread out during a photosynthetic period.
Vodka will also lead to lower ph but does so slowly which enables bolus dosing without quick and large ph drops.
I prefer bolus dosing. It suits my routine ,requires no equipment and hypotheticaly likely enocourages bursts of bacterial growth with increased anaerobic NO3 reduction.
FWIW, I'm a fan of the 21st Amendment .
