Vodka dosing in reef tank



Since the past few years there have been experiments regarding opinions of reputed aquarists about vodka dosing for Probiotics. Probiotics is basically promoting certain psudonomus bacteria with an available carbon source in order to reduce NO3 (Nitrate) and PO3 (Phosphate) levels in saltwater aquariums. In previous posts we have discussed new tank syndrome and ways to tackle. This is also one such method of reducing harmful nitrites from reef tanks, only this method has faced a lot of controversies in past.


Vodka dosing method is simply using the available carbon in ethanol to feed the accessible normal pseudomonas bacteria, which is an anaerobic organism. In response, the bacteria take in NO3 (Nitrate) and PO3 (Phosphate) discharging CO2 (Carbon Dioxide), N2 (Nitrogen gas), H2S (Hydrogen sulfide), CH4 (Methane) and SO2 (Sulfur Dioxide) in gaseous forms. Since vodka dosing is an anaerobic process, no oxygen is required.

The main drawback of this method is the formation of a visible white film known as biofilm on aquarium surfaces. Biofilm is a mass of associated and non-associated bacteria including the nitrobacters and nitrosomos that strive to reside in your “biological filter” and convert ammonia to nitrite and nitrite into nitrate, as well as many other strains. Many of these bacteria not only coexist, but inter-react with each other. When biofilms are extricated and become free-floating they are called “Bacterioplankton.” Bacterioplankton is in fact of use food for many corals including certain species in the kinds of Acropora, Montipora, Pocillopora, Seriatopora andStylophora, plus many other marine invertebrates, such as sponges, tube worms, fan worms and tunicates.

Only those tanks that are highly skimmed with good skimmer are successful in getting the cloudy mass cleaned up. Still there are opinions suggesting that they make the tank unhygienic and harmful for fishes. Also this method can be practiced in tank which lack sand beds. Tanks with sand beds or other sediment-based systems are said to react unusually and may have unfavorable effects to ethanol additions. These drawbacks according to experiments done by pioneers of aquarium keeping are hard to be tackled in most reef tanks as live sand constitute a major part of the sediment and they are no good to the anaerobic process of nitrification.

You might also have to deal with a large bloom that cannot be identified as bacterial or algal and are difficult to be deal with. Some people who used the vodka method of carbon dosing have reported the tissue loss at the ends of their SPS. These are called “burnt tips” and in some cases they have recovered once the user lowered the alkalinity levels within their tank to alkalinity levels closer to natural seawater (7-8 dKH). Sadly, the source cause for this is not discovered yet. There have also been problems relating to pigmentation of most corals. Some recovered and some continued to worsen even after the dosing was stopped. Conclusion is you cannot be sure if your invertebrates and corals are going to tackle the changes or not. Only when you are sure of the safekeeping of the live stock, you can resort to this method.

If you have decided to go for this method, following are the precautions, you will need to take:

1.Uphold your water parameters as close to natural sea water as can be possible. The recommended levels are: Specific Gravity 1.024—1.026; Alkalinity 6.5–7.5 dKH; Calcium 410–430 ppm; Magnesium 1250–1300 ppm; Potassium 380–400 ppm. Pay special attention to alkalinity if you have more corals in your tank.

2.Use good protein skimmer and frequently check for clogging and blockages.

3.It is important that you turn off any ozone or Ultraviolet (UV) Filtration devices in your system while dosing with carbon. These devices will interrupt the production of the bacteria which you are trying to prop up.

4.Never begin with overdosing or high level dosing. Always start slow with small doses and increase gradually with very small quantity keeping an eye on result.

5.Once the tests show desired nitrate and nitrite level, perform frequent water change daily to remove trace minerals.

6.Do not remove overdo the carbon dosing as some amount to phosphate and nitrites are necessary for coral blooms.

7.Keep eye on fishes and invertebrates for bacterial infections. Quarantine them if you find any unusual reaction.

The result of the controversy according to me is that there is no use of following this risky method when so many easier and safer options are available. You definitely can’t be sure of the safety of your corals and fishes with this method. Following the above mentioned precautions is no easy breezy task if you have delicate corals and fishes in your tank. And who wants to share his vodka with the aquarium? At least I don’t!