Vodka Dosing in Saltwater Reef Aquarium


Vodka dosing, also known as the Vodka method, is a technique used in saltwater aquariums to provide a carbon source to beneficial bacteria in the aquarium. This method helps promote the growth of nitrate and phosphate-reducing bacteria, which can help control nutrient levels in the aquarium and improve water quality. It is a form of carbon dosing and is typically used in reef aquariums to maintain low nutrient levels.

Here's how vodka dosing is typically carried out:

Equipment and Supplies:

  • A source of pure vodka (preferably high-quality vodka with no additives)
  • A dosing pump or syringe to add precise amounts of vodka
  • A test kit for measuring nitrates and phosphates
  • A protein skimmer
  • A source of activated carbon

Start Slowly: Begin with a very low dose of vodka. A common starting point is around 0.1 ml of vodka per 25 gallons of water per day. It's important to start slowly to allow the bacterial population to adjust and avoid any sudden changes in water chemistry.

Monitor Nutrient Levels: Regularly test your aquarium's water for nitrate and phosphate levels. The goal of vodka dosing is to maintain low nutrient levels. Adjust the dosage as needed based on your test results. If nitrate and phosphate levels drop too quickly, reduce the vodka dosage.

Protein Skimming: Protein skimming is crucial in a vodka-dosed system. It helps remove excess bacteria and organic matter that may accumulate as a result of the increased bacterial growth.

Activated Carbon: The use of activated carbon in your filtration system can help remove any impurities or toxins that may be released during vodka dosing.

Maintain Consistency: Consistency in dosing is essential. Any sudden changes in the vodka dosage can impact the bacterial population and water quality.

Caution and Observation: Be cautious when dosing vodka and monitor your aquarium closely. Inexperienced aquarists should proceed with caution and consider consulting with an experienced hobbyist or a professional to ensure that vodka dosing is appropriate for their specific setup.

It's important to note that vodka dosing should not be used as a standalone solution for nutrient control. It should be part of an overall nutrient management strategy that includes proper feeding, water changes, and the use of other filtration methods. Furthermore, it's essential to monitor and adjust dosing based on the specific needs of your aquarium, as different systems may respond differently to carbon dosing methods.

Always exercise caution when using any form of carbon dosing in your aquarium and closely monitor water parameters to ensure that you do not create any unintended imbalances in your system.

Vodka Dosing Instructions

1. Your first step is to test your system’s NO3 and PO4 levels. Do not try this method if you don’t know this!!!!!

2. Estimate the net water volume of your system. The water volume is the sum of the aquarium volume, the sump, and refuge minus live rock displacement. It is ok to underestimate the net water volume but it is risky to overestimate it.

3. Start with 0.1 ml of vodka per 25 gallons (100 L) daily for the first three days.

4. Then, double the daily dosage to 0.2 ml per 25 gallons (100 L) for days 4 to 7.

5. On week two, add an additional 0.5ml to the daily dosage, regardless of the aquarium volume. Always test your system’s NO3 and PO4 levels. If your NO3 and PO4 levels start to drop during that 2nd week, maintain the current daily dose. If your NO3 and PO4 do not drop, add an additional 0.5 ml of vodka to the daily dosage on week three. Add 0.5 ml to the daily dosage every week until your NO3 and PO4 start to drop.

6. When your NO3 and PO4 levels drop near undetectable levels, cut your current dose in half. This will be your daily dose.

7. Keep dosing vodka every day (the dose on point 6) and keep monitoring your NO3 and PO4. If levels become detectable again, increase your daily dose by 0.1ml per week until the levels start to decrease again. Your NO3 and PO4 levels will eventually drop back to undetectable. This will become your new daily dose.

Note: These instructions are for 80 proof vodka only (40% ethanol by volume).