Vodka Dosing in a Reef Tank to remove Nitrates and Phosphate

[Marie]

Vodka dosing in a reef tank is a proven method to improve the water quality by removing nitrates and phosphates from the water. Vodka dosing is a technique to reduce or even eliminate detectable levels of nitrate and phosphate from a reef tank. The chemistry involved behind the scenes is actually not specific to vodka–it is ‘organic carbon’ dosing. In the case of vodka dosing, the aquarist has chosen ethanol (ethyl alcohol) as the organic carbon of choice–but other organic carbons could also be used.

Technically, you could achieve the same results by using sugar–and some people do. I don’t recommend using something like maple syrup, which is extremely expensive and has other things in it besides plain sugar, but you certainly could use a sugar solution as a source of carbon if you prefer.

How does vodka dosing in a reef tank work?
When you dose vodka in your reef tank, you essentially feed helpful bacteria with the carbon calories that are in the vodka. By feeding those bacteria the vodka, you cause their population to explode. Those helpful bacteria then later remove nitrates and phosphates from the water column. Pretty cool, eh? So you’re essentially boosting the biodiversity in your tank, which in turn causes the nitrates and phosphates to go down. Awesome stuff.

Why should I consider dosing vodka in my tank?
You should consider dosing vodka in your saltwater aquarium if you are an experienced saltwater aquarium hobbyist and despite proper, appropriate water changes, you consistently have elevated nitrates or phosphates in your tank. Quite frankly, that is probably the majority of advanced aquarists.

How much vodka is needed?
According to the article on Reefkeeping .com, the author recommends a starting dose of 0.1mL per 25 gallons of net water volume per day for days 1-3, followed by 0.2mL per 25 gallons days 4-7, and then the addition of 0.5mL per week (regardless of aquarium volume), until nitrates become undetectable. Please keep in mind that these guidelines were provided based on an assumed alcohol concentration of 40% (80 proof).