Without digging deeply into the scientific area of this, the goal of carbon based bacterioplankton systems such as Vodka, Prodibio, Ultralith and Zeovit is to grow bacteria in order to consumer phosphates and nitrates, which are then exported via a protein skimmer. As the bacteria are removed by the skimmer, so are the nutrient that [...]
Without digging deeply into the scientific area of this, the goal of carbon based bacterioplankton systems such as Vodka, Prodibio, Ultralith and Zeovit is to grow bacteria in order to consumer phosphates and nitrates, which are then exported via a protein skimmer. As the bacteria are removed by the skimmer, so are the nutrient that it consumed. This can be achieved with simple carbon dosing such as sugar, or more complex means such as Zeovit, involving reactors, mutiple dosings and color manipulating additives. (Because the bacteria are exported via skimming, a well functioning skimmer is a must!) The goal of these methods is to create a low nutrient environment, particularly liked by Acroporids.
Here is a photo of Iwan’s reef. He is the one who intrigued us with these methods and this is what can be achieved.
We have experimented extensively with this, and below is the results of various trial and error. Although there is scientific literature to back up the idea behind carbon dosing and the nutrient export as used by bacterioplankton systems, our “dosing” schedule was achieved through observation and experimentation (far from scientific). If you are considering any one of these systems we urge you to read and research as much as you can. The Zeovit Forums have a great archive of information, and there are many heated threads on just about every major forum on this topic. In the end, cardon dosing works, but can be dangerous. Like with any changes to your reefs, start slow.
Because every tank is unique it is extremely important to carefully observe your animal’s reactions. For this reason, there are no set guidelines and carbon dosing of any type should only be done by patient and advanced aquarists.
One of the major concerns with simple carbon dosing is developing a “monoculture” of bacteria. The logic of this being, certain bacteria utilize certain carbon sources better than others. If bacteria strain A utilizes ethanol (vodka) better than bacteria strain B, and you only dose ethanol…all things the same, strain A will out-compete strain B.
Although a true monoculture will likely never occur, because we are an equal bacteria supporter we have created a mixed Carbon Source made up of Vodka, Acetate, and Sugar. Because of the limited shelf life of this solution, we make small batches every two month. Through dosing individual carbon sources, we have also noticed different effects. The make up of this mixed carbon source is based on those observations.
Here you can see the ingredients of our ‘system’: Vodka (ethanol), 5% Vinegar (acetate), and Sugar. (The Gin is for your enjoyment) You will also notice the Prodibio Bio Digest]which I will get into later. This is often referred to on the online forums as glassbox-design VSV or VSV for short.
For this batch we used 200ml’s Vodka, 50ml’s vinegar, and 1.5tbsp sugar. Upon initial mixing, the solution will foam from the vinegar, it should turn completely clear in less than 30mins Depending on the reaction of the tank, we change the make-up accordingly. I have found Vinegar can create unwanted white bacteria growth more so than the other two; if we notice this in the next batch we will reduce the amount of vinegar. For sugar we notice more surface film. Again if this occurs we reduce the amount added to the next batch. As we have already achieved low nutrients we currently only dose 0.2ml’s of this VSV solution daily on a 100g total volume system.
A good starting point is 0.1-0.5ml per 20g. This may seem like very little, but it is best to start slow and increase the amount over time to prevent a bacteria bloom. This occurs from overdosing a carbon source which then clouds the water milky white. Unfortunately this can cause systems to crash from oxygen depletion as the bacteria utilize what available oxygen there is, suffocating your fish and corals. (Another reason why a powerful protein skimmer is a must when using these methods).
When dosing carbon, you do not always get the bacteria you want to grow. To help this and create a diverese bacteria population in the water column we dose BioDigest to add diserable strains.
Bio Digest is packaged in small glass ampoules with nitrogen gas (cool huh?). In these small vials are both nitrifying and denitrifying bacteria. Specifically the Strains are Nitrosomonas europea, Nitrobacter winogradskyi, Paracoccus denitrificans, and Pseudomonas stuzerii. Prodibio claims they contain 20 Billion bacteria per ampoule.
Due to the life cycle of the bacteria, they recommend dosing every 15 days and as such we follow. We currently are dosing 1 ampoule on our own tank, but when transitioning the livestock to it’s new home we will use a double dose to help keep ammonia, and nitrate down during that high-stress time.
One highly important aspect of these system is mimicking natural seawater parameters. Alkalinity fluctuations in particular can be damaging. We aim for Alk 7.5 (w Seachem Reef Salt ~6.5 true alk due to borate content) Cal: 420 Mg: 1300. We also do weekly 10-20% waterchanges to keep proper levels of trace elements and supplement with Amino acids and Potassium iodide. These trace elements are extremely important to coloration of SPS as well as bacterial growth.
For more info on Aminos’ check out this article: Do they work?
Carbon dosing is not for everyone, however it works for us. There is risk involved and please do not try this unless you are up to the task and have done your research. We are not responsible for tank crashing, or your acroporas becoming more colorful…all of that is your own doing.
We hope sharing our experiences helps others and can spark new ideas in this area.