<a href=showthread.php?s=&postid=11885889#post11885889 target=_blank>Originally posted</a> by Genetics
Hey everyone I was combing through this thread and thought I would chime in on a few topics.
First, vodka is pretty pure ethanol, in regards to other alcohols such as whiskey, wine, or rum, though it may differ slightly from manufacturer to manufacturer. Vodka differs because it has all other flavoring agents (contaminants to our tanks) removed. Vodka is good for dosing a tank because it is run through carbon up to three times (triple distilled) and the final product you buy is water and ethanol (CH3CH2OH). This is why it has very little taste to it (and the women prefer it in their mixed drinks). Depending on the proof you will want to differ your dosing amounts. I think people are still investigating on the optimal dosing amount. Though there are threads that give you a good starting point. So increasing proof is only slightly decreasing the accuracy of which one is effectively measuring ethanol addition to the tank. The error comes in measuring. If you measure 8mL at 20 proof you will be more accurate than measuring 2ml at 80 proof.
Second, vodka will be found to work differently than sugar (sucrose is your table sugar of choice). Sucrose is composed of glucose and fructose, each consists of a six carbon ring that is hydrated for efficient energy release by breakdown through glycolysis/kreb cycle. This will most definitively stimulate growth of organisms that cannot efficiently convert ethanol to an energy source but may be beneficial in its own means.
Third, Ethanol has no defined pathway in our tanks yet, however, I would like to point our attention to three groups of organisms that stand out. Methanogenic bacteria such as Methanobacterium omelianskii are a great candidate, though not the only/major participant. As a saltwater growing organism Methanobacterium can cooperatively interact to reduce sulfates by H2S reduction from use of ethanol as a substrate with peak growth taking 4-5 days (a bi-product is acetate for the vinegar dosers). I am wiling to assume that this bacterium is found in ethanol treated tanks in higher numbers. The H2S reduction also should be noted as deep-sand beds (DSB) initially take in and eventually reduce sulfurs as well. This may explain coral coloration and improvement after using consistently for a few weeks, as coloration and growth has been noted in DSBs. The second group would be the syntrophic organisms such as Clostridium or Desulfivibrio that act in a dependent manner requiring a growth and production of H2, which would be a byproduct from M. omelianskii. These three could act co-operatively and synergistically to help reduce sulfur from the system.
Would this H2S production drop ORP readings in our reef ecosystem? If the released product is H2S then adding too much at once could do this. However, as dosing tolerance can be built up then there are further cultures in play here; nitrate reduction for one.
