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Carbon Dosing for Reef Tanks
Last updated on November 17th, 2023
What is Carbon Dosing for Reef Tanks?
Biological filtration is a natural filtration method provided by nitrifying bacteria to remove nitrates from the reef tank. This beneficial bacteria consumes carbon in order to grow and multiple. Carbon Dosing for Reef Tanks is a method of feeding this bacteria in order to help it multiply and remove even more nitrates from the reef tank. Therefore, carbon dosing is a method of providing your biological filtration with the carbon it needs in order to remove nitrates from your reef tank.
Reduce Nitrates and Phosphates with Carbon Dosing
Straight to the point, I know. Carbon dosing has one benefit, reducing nitrates and phosphates in the reef tank. I am assuming, by the time you find this article, your nitrates and/or phosphates are causing problems in your reef tank. Please be cautious here. Dumping a large amount of carbon suppliments in your aquarium will only make things worse! Sudden changes, even reducing nitrates and phosphates, can cause bleaching or death in coral and fish. Please read this article carefully, and make changes slowly.
Common Methods of Carbon Dosing in Reef Tanks
There are a variety of ways you can add carbon to your tank. Some examples of organic carbons for your reef tank include:
- Vodka Dosing (One for me, one for the tank)
- Sugar Dosing
- Vinegar Dosing
- Bio-Pellets
Vodka Dosing for Reef Tanks
Vodka Dosing for reef tanks is one of the most popular methods of carbon dosing reef tanks. It is cheap - the fish don't need top shelf ;) - and easy to get at most stores. Though it should go without saying, do not use flavored vodkas, or anything with added flavors or colors. Just cheap, simple, distilled vodka.
How to Dose Vodka for Reef Tanks
Before you start carbon dosing, you MUST have a protein skimmer running in your reef tank. As the bacteria consumes the nitrates and phosphates, the protein skimmer is what removes these nutrients from the water. Otherwise the nutrients will remain in the water and this will be a waste of time and money. The long and short, make sure you have a good, running protein skimmer.
Type of Vodka: Cheap 80 Proof Vodka, no added flavors, colors, etc.
- Test your current Nitrate and Phosphate Levels. You MUST know your starting levels in order to use carbon dosing. If you don't, you will likely over or under dose your tank. My prefered test kits are the Red Sea Nitrate Test Kit and the Hanna ULR Phosphate Checker.
- Days 1 - 3: Dose 0.1ml per 25 gallons of water each day.
- Days 4 - 7: Dose 0.2ml per 25 gallons of water each day.
- Week 2: Add 0.5ml to the amount being dosed, dose this amount each day this week. For example, a 55g tank would dose 0.94ml (okay, 1ml, be real) each day.
- End of Week 2: Measure nitrates and phosphates using the Red Sea Nitrate Test Kit and the Hanna ULR Phosphate Checker. Repeat steps 4 and 5 (Adding 0.5ml each week) until you see nitrates and phosphates reducing.
- Once your Nitrates and Phosphates start to decrease, dose this amount until nitrates and phosphates are at the desired level.
- Maintenence: When your Nitrates and Phosphates are at the desired level, cut the amount of vodka dosed in half. Continue to dose this amount to keep nutrients in check.
Vinegar Dosing for Reef Tanks
Another popular method of dosing organic carbon in the reef tank is vinegar dosing for reef tanks. Vodka is more popular as it contains roughly 8 times more carbon per mL than vinegar. However, this means that you are able to have finer control with vinegar as compared to vodka. Most lower cost automatic dosing pumps (such as the Jebao DP-4 Dosing Pump) have an accuracy around 1mL. Trying to add 0.5mL of vodka would require you to dose by hand, or use a more expensive dosing pump, like the EcoTech Versa Dosing Pump.
Enter vinegar dosing. Requiring 8 times as much means that adding the same amount of Organic carbon as 0.5mL of vodka would need 4mL of vinegar. You will go through far more vinegar, but it helps maintain accuracy for the short term.
How to Dose Vinegar for Reef Tanks
Much like vodka dosing, before you start, you MUST have a protein skimmer running in your reef tank. The skimmer removes the nitrate and phosphate from the tank by removing the bacteria after consuming the nutrients. The below will be nearly identical to the Vodka dosing section, with the amount needed to dose being adjusted.
Type of Vinegar: Pure white distilled vinegar (5%) with no other additives
- Test your current Nitrate and Phosphate Levels. You MUST know your starting levels in order to use carbon dosing. If you don't, you will likely over or under dose your tank. My prefered test kits are the Red Sea Nitrate Test Kit and the Hanna ULR Phosphate Checker.
- Days 1 - 3: Dose 0.8ml per 25 gallons of water each day.
- Days 4 - 7: Dose 1.6ml per 25 gallons of water each day.
- Week 2: Add 4.0ml to the amount being dosed, dose this amount each day this week. For example, a 55g tank would dose 7.5ml each day.
- End of Week 2: Measure nitrates and phosphates using the Red Sea Nitrate Test Kit and the Hanna ULR Phosphate Checker. Repeat steps 4 and 5 (Adding 4.0ml each week) until you see nitrates and phosphates reducing.
- Once your Nitrates and Phosphates start to decrease, dose this amount until nitrates and phosphates are at the desired level.
- Maintenence: When your Nitrates and Phosphates are at the desired level, cut the amount of vinegar dosed in half. Continue to dose this amount to keep nutrients in check.
Other Organic Carbon Products for Reef Tanks
Often times, there are obvious concerns with adding non-aquarium products such as vodka and vinegar to the reef tank. Sometimes impurities and other chemicals tag along and can cause all sorts of damage. Though vodka and vinegar are generally safe, there is always a risk. If you are looking for products created for the reef tank, there are other carbon dosing options for reef tanks.
Bio-Pellets and Bio-Pearls
Bio-Pellets or Bio-Pearls are a form of organic carbon pellets that are designed to dissolve when tumbled in a BioPellets Reactor (such as this one by Reef Octopus). Cheaper reactors may be used, but if the bio-pellets clog up, they can cause a nitrate trap instead.
Nitrate and Phosphate Reducing Chemical Additives
Other nitrate and phosphate reducing additives also utilize organic carbon dosing for reef tanks. Here is a short list of available products:
Conclusion
Organic Carbon Dosing for Reef Tanks is a very common method of reducing nitrates and phosphates from your reef aquarium. Though vodka and vinegar dosing are the most common methods of carbon dosing, sugar and other supplements can be used as well. It is very important to ensure you have a skimmer running and do not over dose carbon as it may lead to more problems in the long term. If you keep an eye on your parameters, and go slow, you will likely be amazed with the results you can achieve with something as simple as carbon dosing your reef tank.
References
- Reef Aquarium - CARBON DOSING IN LAYMAN’S TERMS
- Reefkeeping Magazine - Vodka Dosing...Distilled! - A Powerful Method for the Reduction of Nitrates and Phosphates within the Reef Aquaria
About the Author
John Krenzer
John is a Software Engineer with a passion for saltwater aquariums, as well as the founder and president of Reef Stable. He started in the aquarium hobby as a child with a 20 gallon freshwater aquarium. His interest in aquarium life grew and in 2008, John set up his first saltwater aquarium.
Today, John maintains an over 300 gallon reef tank system, consisting of a 120g reef and a 210g reef. These large tanks are contained within the same system, sharing a sump as a means to reduce total maintenance and increase total water volume.
John writes articles for the blog as a means to learn about more reef aquarium topics. These articles act as a reference for the readers as well as himself. John updates these articles frequently to provide additional information or make corrections as new information becomes available.
If you would like to request an article, tank tour article, or to collaborate, let me know via the Contact Me Page!
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