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So lets continue talking about this ‘hot new method’ of supposedly reducing PO4s and NO3s.
While researching this topic, I stumbled upon Eric Borneman’s 2004 ReefKeeping article, which goes in depth covering this exact topic. In Eric’s words, this ‘new’ concept was titled ‘The Old Becomes New, Yet Again”, five years ago. Why are we revisiting this now? In time, you will see..
In this article, Eric uses a German reef magazine’s ‘experiments’ (as he called them in quotations) to explain his displeasure of applying this theory in practice.
German magazine recently published an article suggesting and recommending the dosing of ethanol (as vodka) to reef tanks as a carbon source for marine heterotrophic bacteria in order to increase denitrification rates and bacterial biomass production (Mrutzek and Kokott 2004). Further, they claimed that additions cause rapid declines in nitrogen and phosphorus produced by fish, invertebrates, and algal metabolism (ironic, since many aquarium invertebrates and algae are sinks, not sources, for nitrogen and phosphorus). In turn, the bacteria provide a food source for corals and other filter feeders. The method is recommended particularly for those tanks that are highly skimmed (and probably lack particulate material) and which lack sand beds. Tanks with sand beds or other sediment-based systems, they mention, react unusually and may have adverse effects to ethanol additions.
He continues to elaborate on what this experiment managed to do.
“Experiments” were performed (and I use the term experiment loosely to mean the typical uncontrolled, unreplicated, statistically insignificant sort of “let’s add it, see what happens, and produce results that show how my tank never looked better” sort of trials that are often found in aquarium literature). The results showed a precipitous decline in nitrogen and phosphorus levels over approximately one month with increasing doses of vodka. The sample size for the experimental procedure was one (n=1), consisting of a single person’s personal home aquarium. There were no controls in the experiment (i.e. an identical tank without vodka being added to see if there actually were results from the treatment). In fact, the sample tank received an increasing dose of vodka during the treatment, making any dosing effect impossible to determine. Additional support for the “experiment” was collected by casual replication in completely different trials in even less controlled conditions; that is, other aquarists began adding vodka and claimed similar “results.”
Side effects of this experiment?
Results of this work also showed a number of other effects. A large “bloom” occurred which clouded the test tank, an occurrence that could and often does kill tank inhabitants. It was assumed the bloom was bacterial, but no mention was made if and how the cloudiness in the tanks was determined to be bacterial. Given what I will offer below, it may also have simply been carbonate precipitation brought about by additional carbon addition and possibly microbial mediation. Having fortuitously escaped tank mortalities, the tank cleared and the authors literally state how “the tank water had never been clearer, the coral polyp extension was better, and the coral coloration was more intense.” Where have I heard this before?
To prove his point, he broke down all possible avenues in denitrification within the walls of your tank.
First, no denitrification rates, to my knowledge, have been measured in aquarium sediments or substrates outside those provided by Toonen (although they have been measured often in the field, as discussed below).
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Second, most aquarists using live sand beds believe that top aerobic (oxic) layers overlay the anoxic layers where denitrification takes place. However, denitrification can also take place in oxic areas, and some of the highest rates of denitrification have been found in the top 1 cm of sediments where nitrate and oxygen levels are highest (Oren and Blackburn 1979).
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Moreover, denitrification has been shown to be a nitrogen-limited and not a carbon-limited process, though carbon limitation is central to the premise of the vodka-addition treatment. Without question, the denitrification process is microbially mediated, but unfortunately little, if any, evidence exists that microbial populations in aquariums are carbon-limited.
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Because of hydrodynamics across surfaces, microbial community dynamics, and other biotic and abiotic influences, oxic/anoxic zones can be found virtually everywhere in an aquarium. Denitrification has been found to exist on the surface of detrital particles, on the surface of corals, and on the surface of sand grains that are found in oxic environments. Therefore, denitrification and even sulfate reduction can be considered microaerophilic processes that do not depend on anoxia to take place.
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Furthermore, plants are able to utilize denitrification pathways, and aquariums contain high numbers of these; macroalgae and photosynthetic single-celled organisms, endolithic fungi, bacteria, coralline algae, and highly grazed turf species are among those functional biotic components present but remaining largely unseen or not considered in such speculations on nitrogen dynamics in tanks, and none of which are requisite to the presence of a sand bed. Sponges have been found to be able to denitrify, too, through their association with endosymbiotic bacteria. Corals are covered with a rich microbial surface community that includes many alpha- and gamma-proteobacteria that are known to be denitrifiers. In fact, anoxia is now known to exist within coral tissues at night, and studies are underway to determine how corals are able to survive this environment (Kulhanek, et al. 2004).
In other words, there are numerous areas of denitrification within your tank. Within your rocks, your sand, your plants, your corals, in oxic (oxygen rich) & anoxic (oxygen poor) areas, and even on detritus.
So if a lot of things that are in your tank already denitrify, then why do we even bother with this possibly dangerous process? Why do we risk dosing ethanol (carbon) into our systems? Is it a less involved process of removing nutrients? Is it a faster method of eliminating your nuisance algae? Eric wrote:
Now, I may not know much, but I do know that in the twenty or so years that we have been keeping corals alive, it has become obvious that the apparatus that was so heavily depended upon in the early years to simply maintain corals, such as denitrators, bioballs, phosphate removal media, and others, is no longer required. John Tullock (1997) stated eloquently that we needed “more biology and less technology.”
Wouldn’t a very simple water change accomplish a lot more than dosing yesterdays hot new cure-all item? Lets get back to roots people! Less is ALWAYS more in this hobby.
Trained by the thirteenth ring master of the Sian Xiuang Coral Temple. Currently is apprenticing the art of Acropora shaping in the ancient tradition of Ninja Fragging. Known as the SPS hero!
You raise some good points about the whole vodka dosing fad… about 4 -5 years back I remember reading somethings about adding sugar (and vodka) to your tank… oh well …think I’ll just stick to the proven ULNS methods (ZEOvit).
Great blog and I like your anti-vodka stance and not following the trend. Keep the posts coming.
Maybe I missed it — where exactly did Borneman explain why carbon dosing is bad? He certainly complained about poor experimental design (something he clearly knows about, considering his recent salt mix “study”) but never is able to pull the trigger on the technique itself. One ten year old anecdote of someone overdosing their tank and getting a bacterial bloom isn’t persuasive.
Of course there are multiple areas of denitrification in an aquarium. What does that have to do with adding carbon? Nothing. Of course the first people experimenting with the technique had problems. Does that mean that current protocols will do the same? No.
I had persistent high Nitrates. I started dosing sugar, and over the course of a month or so my nitrates dropped to under 5ppm. No cloudiness, no crashes, just no nitrates.
Many corals can do fine in an aquarium without feeding. However, if you take the extra step and feed them they’ll do better. It’s the same thing with the nitrogen-cycle bacteria. Leave them alone, they’ll do fine. Feed them (carbon) and they’ll do better for you.
It’s *not* technology, it *is* biology.
Andy, he didn’t say its bad, he just said that its not needed. There are many pitfalls with dosing it, and only advanced reefers should partake in this method.
If you scan the forums, many people are posting questions of problems after dosing. They do not have the experience to know how a system reacts to certain things added. So again, you can dose it to lower your nitrates, but I would only recommend it to those who have the vast experience.
Refugiums do wonders for reef systems. I just wonder why haven’t people embraced that?
Curveball, thanks for reading!
As a seasoned reefer, I apply a very natural method of removing phosphates and nitrates: refugia and (at times) water changes.
Sure I would try to dose a carbon source to see how it would affect algae in my system, but it would be under ‘experimental’ circumstances.
(from your 3rd comment):
“If you scan the forums, many people are posting questions of problems after dosing. They do not have the experience to know how a system reacts to certain things added.”
That’s an issue I see – people just jumping in, instead of reading up on the processes taking place when ethanol (or whatever C source) is added to the tank. It appears some are not taking time to learn it, just taking time to figure out an appropriate dose and start.
My opinion is that carbon source is a very effective way to lower nutrients *safely* in a reef tank. It’s just a matter of understanding what’s happening so one can act appropriately as they observe changes (for better or for worse) in the tank.
I’d also add that I use both refugium and c – source addition. Although, were I to give up one in favor of the other, the macro algae would definitely be there to stay.
Eric’s two articles published in 2004 on this subject clearly state the unknowns and the problem with the “experimental” process. Two main issues that arose from the course of the experiment was the continuous increase in vodka and the experimental size without proper controls. However, the concept behind vodka dosing is rather strong. In fact, balancing N/P to deficient C (by deficient I mean easily assessable by heterotrophic bacteria for growth) is the goal of any reefkeeper and is the pinnacle of good husbandry.
If you search the scientific literature you can find studies where additions of organics can cause coral mortality. Arguably this is due to stimulation of bacterial populations on the coral to plague proportions. Though if you keep in mind the amounts needed for mortality and look at the types of organics they are using you will clearly note that the levels are 10-1000 fold higher than what is required for N/P correction. Also you will see that some sugars cause harm while others do not elicit such a response. HTH.
You are absolutely right Nathaniel. This is why it is good for novices and even some intermediate reefers to apply different methods to lower their PO3 and NO3 levels. There are risks, many by those who don’t understand them, that can outweigh the positives. And as you said, not all sugars will yield the same result. But, if you do know how to apply this method, and are confident, then it can work for you dramatically.
vlad, you are absolutely correct. Though not a magic bullet, it allows reefers to correct a sometimes daunting issue that causes frustration and people to leave the hobby. What is fascinating about this approach is that it can be used in conjunction with any methodology of nitrate/phosphate removal being employed under the berlin system. I’ve seen tanks with refugiums attached, with GFO being used, and algae turf scrubbers all employ carbon source dosing. Though not a necessity by any means, this allows a reefer to explore vodka dosing without changing their setup and a quick means to return to their old husbandry practices.
I would also like to comment on this post “about 4 -5 years back I remember reading somethings about adding sugar (and vodka) to your tank… oh well …think I’ll just stick to the proven ULNS methods (ZEOvit).” This underlines the misinformation floating around. Zeovit employs similar carbon source dosing strategy to bring about nitrate/phosphate reduction. If one is worried about EB’s thoughts on vodka dosing, they should also worry about zeovit. With the former, you at least know the composition of the materials you are adding to your aquarium.
Seriously,
I’m not the advance aquarist but I did a lot of research about this method, the solution is for every one a little bit different, becouse of starting point of your aquarium water quality and chemical stadium.
From the economical point of view, this one is the best solution for everyone, not only for companies podcuing all aquarist technical solution, so they will try to put this method in the worst picture as possible.
If you are aquarist take a test yourself build a small QT and one fish one inverst and small live rock with one coral, remmember about filtration and protein skimmer in your small tank. Add significant smaller abount of vodka, recalculated dosing and find out if its work.
And massege for all companies making money on us, go home… and find easier solution than charging us 300$ for peace of plastic and a little of bio balls in it…
Aquarists good lock, with reaserch you may find new solutions better ways.
regards
I have used vodka/vineagar/sugar combination in my 470 acrylic FOWLR and my 230 acrylic reef for ages now. I used to have 300 plus nitrates in my FOWLR with no method to reduce them working. I now maintain 0-5 ppm and my livestock is more active, colorful, and happier than ever after 2 years of dosing. My reef was only about 20-30 ppm but is also at the 0-5 level now. all corals show more vibrant colors and health, as well as all fish and inverts. I am sold on this method and have gotten many others into it. They have had the exact same success as I have. Best of luck to all fishkeepers/reefers.