Chemistry Guru's chime in please...

[Nanook]

I am told that vodka dosing is not necessarily approved by the regular leaders of this forum and I would like to know your reasons for why you are against it. Please include arguments to support your position so I can make an educated decision about the risks and benefits to this type of nitrate control.

Thanks

 

[kaskiles]

I'm not a forum leader, but I believe Randy started to try it. His ORP started to suddenly drop at the same time. He stopped posting recently, so I wasn't able to keep up with if ORP and Vodka were related.

I'm able to keep my measured nitrates below detection with skimming, GAC and water changes. Based on my experience with dosing pumps and Kalkwasser, I'd rather use those easy to control methods over a potentially sensitive chemical one.

I'm not home to manually dose each day though, so I might be biased...

 

[HighlandReefer]

Nanook,

Carbon dosing is but one means to help control nitrate. If a hobbyist can control the nitrate level in their system without using carbon sources, then I would not use this method.

Using carbon sources in a reef system is a complicated subject and as in any other method you choose to use to lower nitrate, it can have draw backs and cause problems to occur due to the complexity of how it works in a system.

The primary concern I have with possible problems when using carbon sources to increase the bacterial populations, is the dissolved organic matter produced by bacteria, cyanobacteria & other phytoplankton. Some of the chemicals produced can be quite toxic and with increased populations of bacteria, these toxins can be increased as well. Bacteria and cyanobacteria have developed defense mechanisms over the millennium. The Internet is loaded with articles regarding the toxic substances that bacteria and cyanobacteria as well as algae & other phytoplankton found in our system. This is complicated further by the toxic substances that coral produce as well.

The mechanisms used to remove organic matter in our tanks leaves something to be desired. The best skimmers, running GAC and water changes do not remove the TOM to proper levels according to most research I have read. This is one reason why municipal aquariums run special filters (diatomaceous earth filters) to help remove the TOM produced in such large water volumes. IMHO, the cyanobacteria outbreaks reported by many hobbyists who dose carbon sources many be attributed to this DOM increase in the water column.

That said, many hobbyists have used carbon sources in their tanks with what appears to be successful results. Carbon source overdoses can lead to bacterial blooms and one has to be careful to watch for this. In a system as large as yours the amount of vodka (carbon source) you will need to use on a daily basis is quite large. I would be concerned that if too much is added to your system at one time, it can have adverse effects on the localized area you apply it. Therefore, I would dilute it and apply your carbon source over an extended period of time.

You may find this search regarding your question interesting. Unfortunately, the most interesting articles must be purchased:

http://scholar.google.com/scholar?s...ating+systems:+Theory+and+applications+&hl=en

 

[rsuplido]

You can also follow this thread, which is I think already split in 4 parts: http://reefcentral.com/forums/showthread.php?s=&threadid=1436138

Sonny is quite helpful so if you want to ask anything about vodka, he should be able to help you. This is the last part of the thread: http://reefcentral.com/forums/showthread.php?s=&threadid=1666271

 

[JCR's Reef]

Sonny gives excellent advise and has results to prove it..
But like someone said. If you can control your nutrient levels w/o vodka I dont see why you would start.
I dose Vodka in a cycle then take a break when everything clears up or becomes too clean. I also dose MB7 which cant be out weighed by the vodka. MB7 has treamendous benefits to it and I would dose this along with vodka if you decide to go that route

 

[kaskiles]

Sorry to get off topic, when I saw the MB7 acronym I had to go search engine it. I landed at the marine depot product description:
http://www.marinedepot.com/Brightwe...-Brightwell_Aquatics-BW01220-FIADWTBS-vi.html

Does it really say this in there:
Supplied in a state of suspended animation for maximum longevity.
?

 

[Nanook]

<a href=showthread.php?s=&postid=15554790#post15554790 target=_blank>Originally posted</a> by kaskiles
I'm not a forum leader, but I believe Randy started to try it. His ORP started to suddenly drop at the same time. He stopped posting recently, so I wasn't able to keep up with if ORP and Vodka were related.

I'm able to keep my measured nitrates below detection with skimming, GAC and water changes. Based on my experience with dosing pumps and Kalkwasser, I'd rather use those easy to control methods over a potentially sensitive chemical one.

I'm not home to manually dose each day though, so I might be biased...

I believe Randy was dosing up at a very, very fast pace....correct me if I am wrong, I do not believe he was dosing per the recommended guidelines in the article by Nate.

 

[Nanook]

Thanks for the open discussion on a somewhat ?controversial topic I think there are a LOT of people dosing vodka in our membership and it is important that we can have open dialogue in this forum especially since this is a water chemistry treatment.

For the record, I have 1200 gallons of saltwater and the last ten years involved in keeping multiple saltwater systems. That said, it should be obvious that I know the basics of proper husbandry, water changes, carbon, chemistry, etc, etc. In spite of water changes, carbon, etc, my nitrates like to climb into the mid 20's because of a heavy fishload and large additions of food.

I have one of the largest skimmers built for hobbyist tanks by GEO which does an absolutely amazing job at remove scum. I change water monthly, albeit only 225g at a time, which is about 20% total water volume. I have run carbon and GFO since the getgo, but nitrates have been uncontrolled without dosing. I added a refugium for macroalgae export and it grows like weeds.

I started dosing back in December 2008 if memory serves, but would have to look at my records. It took a long time to ramp up going slowly with the vodka only, but I am currently at 80cc/day divided into 4 doses. Nitrates have been reduced from 23 to 2-4 at present. Vodka does not do much for phosphate reduction in my observation because when I removed the GFO, the phosphate went from 0.02-0.03 to 0.11 in a few weeks.

I think the lack of embracing by some of the chemists is that there is no scholarly study or thumbs up by someone like Randy. If that was the case, it would be promoted and stickied at the top most likely. Just some discussion of our observations and perhaps a controlled experiment by some of the chemist gurus might go a long way to legitimizing this form of nitrate reduction.

 

[tmz]

I agree with Cliff's summary.

I started dosing vodka about 5yrs ago since I liked the notion of a bacterial scrubber. I discontinued it after 4 months as I read more and became concerned about the potential for total organic carbon buildup given the questionable ability of skimmers and even gac to take out as much as is dosed. I also became concerned about wether the bacteria I was growing were beneficial, benign, pathenogenic or all three . I did not see any ill effects and noted a decline in bryopsis and xenia growth at that time.

As my system grew in bioload it became increasingly more difficult to manage PO4 and NO3 Even with macro refugia, dsbs, gac ,heavy skimming, levels were not acceptable. Many solid reefers were using carbon dosing( vodka, vinegar ,sugar and/or commercial products) . When Randy decided to try it , I waded slowly back in.

I have been dosing relatively small amounts for 186 days ( 24ml vodka and 2ml vinegar for 550 gallons). I also use the same amount of gfo I used before dosing , maintain the same chaeto refugia, sim heavily and use gac 24/7 as I did before introcuing the extra carbon. The results have been very good. PO4 holds at about .05ppm , nitrates at under 2ppm. Before adding the carbon to the nutrient export array, PO4 was always .15 plus and nitrate rose as high as 60 ppm( I did knock the nitrate down with a sulfur denitrator since the carbon dosing at low levels didn't seem to get it).

I've had very minimal patchy cyano and a spot of hair algae here and there in one of the frag tanks. No other ill effects to note. it does drop orp abut 20 points when dosed but the opr comes back up within an hour or so.Water is quite clear, and as noted nuisance algae is almost non existent.

I think keys are ; slow and minimal use, adequate means to export the TOC (and the bacteria carrying it) and using it in conjunction with other methods for nutrient export to minimize potential downside risks from TOC accumulation or bacterial blooms. I wouldn't use it if the other methods in moderation worked without it since I don't think a carbon source directly acts as any kind of a coral food.

 

[ScooterTDI]

For what it is worth, some wastewater treatment facilities implement a biological denitrification system that requires methanol to be fed into an anaerobic reactor. Its the same principal as vodka dosing, but with vodka dosing, you are adding it to the bulk water that is mostly well oxygenated and not where denitrification is occuring.

I would be interested if direct application of the alcohol to the anaerobic zones (such as the sand bed) would be preferable to adding it to the bulk water. I am imagining using a very diluted alcohol solution and feeding into the sand bed with a syringe or possibly placing a network of piping within the sandbed through which the alcohol can be injected and evenly distributed.

Scott

 

[tmz]

Carbon based denitrators are in use in aquariums as are sulfur denitrators.
As for the sand bed some bury sulfur , so injecting carbon would be similar. A problem with this approach in a deep sand could be carbon or sulfur in anoxic areas feeding heavy heterotrophic reducing bacterial activity using sulfate (SO4) for oxygen when nitrate is depleted. The SO4 reduction would produce hydrogen sulfide as a by product.

While carbon dosing may be enhanced by adequate surface area , I believe carbon dosing relies more on faculative heterotrophs ( bacteria that can not use inorganic carbon ; must have an organic carbon source ;and, thrive in both oxic and hypoxic conditions.) than solely on heterophic anerobic bacteria that must have low oxygen areas.

 

[ScooterTDI]

I understand now, assimilatory nitrate reduction is the goal of vodka dosing, not denitrification. I should have known that.

Scott

 

[bertoni]

With a heavy fish load, dosing carbon might be one approach to reducing nitrate or phosphate, or both. There are a number of downsides. I'll try listing the ones I remember:

1) As noted, the bacterial growth can be harmful, due to toxins, perhaps, or even oxygen depletion, in extreme cases.

2) Bacterial films can develop, which leads to higher maintenance.

3) Corals sometimes react negatively, perhaps due to the toxins mentioned, or for other reasons.

For many systems, a higher nitrate level is acceptable. Depending on how the animals are doing, the cure can be worse than the disease. Coloration is the most subjective of the effects, but coloration is not necessarily correlated to animal health, and everyone's taste is different.

Carbon dosing grows a potentially wide variety of organisms, a new or larger food chain, which we haven't identified and have no means of observing or measuring, so I view it with caution. Dosing calcium chloride has effects that can be quantified very easily. Carbon dosing is a different beast altogether.

 

[Nanook]

<a href=showthread.php?s=&postid=15557023#post15557023 target=_blank>Originally posted</a> by bertoni


1) As noted, the bacterial growth can be harmful, due to toxins, perhaps, or even oxygen depletion, in extreme cases.

Any idea what kinds of toxins that could develop? On the oxygen depletion, would continual monitoring of ORP be a good safety net? How about ozone generator to keep ORP at a slightly higher than normal level as a safety net?

 

[Nanook]

<a href=showthread.php?s=&postid=15557023#post15557023 target=_blank>Originally posted</a> by bertoni


2) Bacterial films can develop, which leads to higher maintenance.

3) Corals sometimes react negatively, perhaps due to the toxins mentioned, or for other reasons.

On the bacterial films, they are a reality. I have noticed them in the plumbing pipes that don't get light. It is a tan film covering that washes out easily and doesn't seem to cause flow issues so far.

As for the corals, a good visual check is done daily at least on my part and they appear to be doing well. There was a time where I was losing acros, but I think that was from unstable alkalinity levels but not sure.

I guess I am leary of vodka dosing as well and would like the chemistry stamp of approval. It is definitely effective at nitrate reduction and is very affordable, especially with a hobbyist with a large system like myself. Running GFO does keep phosphates at bay, but keeping nitrates reduced via water changes on a 1200g system is VERY expensive and time consuming.

So far, I am enjoying the benefits of vodka dosing, but would like to see some arguments or stories of disaster. I am also open to other methods of effective nitrate reduction. What do you think of sulphur denitrators versus vodka?

Thanks for taking the time to respond too, I really appreciate it!!

 

[HighlandReefer]

<a href=showthread.php?s=&postid=15558380#post15558380 target=_blank>Originally posted</a> by Nanook
Any idea what kinds of toxins that could develop? On the oxygen depletion, would continual monitoring of ORP be a good safety net? How about ozone generator to keep ORP at a slightly higher than normal level as a safety net?

Role of elevated organic carbon levels and
microbial activity in coral mortality
http://phage.sdsu.edu/research/pdf/Kline - DOC and coral death 5-24-06.pdf

From this article:

"RESULTS
Coral mortality in ecotoxicology
experiments
Treatment of corals with phosphorus
or nitrogen sources did not cause significant
mortality in five 30 d experiments
with respect to the seawater controls
(Fig. 1; p > 0.1, Mann-Whitney U-test).
Coral mortality caused by DOC treatments
was on average 5-fold higher
(36.6%), and significantly different
compared to controls (p < 0.001). Individual
treatments that had significantly
greater mortality compared with controls
included 25 mg l"“1 lactose (p < 0.001),
25 mg l"“1 starch (p < 0.01), 25 mg l"“1
galactose (p < 0.05), 12.5 mg l"“1 glucose
(p < 0.05) and 25.0 mg l"“1 glucose (p <
0.05). Organic carbon treatments
caused pathologies similar to those reported
for band diseases, with a progressive
loss of tissue starting at the colony
margins, as well as rapid sloughing of
coral tissue. Similar mortality patterns
due to DOC loading were also observed
in 4 previous culturing experiments
using a simpler culturing system in
Panama and Puerto Rico (data not
shown). Naturally occurring reef POM
caused significant bleaching of the corals
in both treatments (Fig. 1, p < 0.005).
Microbial growth rates
After 26 h, microbial production had increased
by almost an order of magnitude on corals treated with
D-glucose, and was significantly higher than in the
controls (p < 0.001). In all of the other treatments,
microbial growth rates were approximately constant
and were not significantly higher than the controls (p >
0.05, Fig. 2)."

 

[HighlandReefer]

Randy orginially thought there was an orp problem when dosing his vodka, but after a period of time realized that his meter had problems and was reading incorrectly.

 

[bergzy]

before i had to reload my computer os...i had an an incredible article bookmarked regarding ethanol and acetic acid in bacterial growth.

it concluded that ethanol had exponential growth on bacteria.

the bacteria in 'our' systems are the ones, in theory, that consume nitrates and phosphates creating oligotrophic bacterioplanktonic system that is very nutrient poor but high in planktonic life that corals could consume.

this is the big mystery behind all bacteria based systems like zeo, prodibio, fauna and the list goes on.

i dosed vodka for a couple of years which created a nice low nutrient system...but as my life has gotten busier...i have slacked on dosing and decided to stop it. but...i did have great results while doing it!

 

[tmz]

I would add the concern about the build up of total organic carbon to that list.

Coloration aside, high nitrates(20 ppm+ or so ) can be deadly for some corals ,in my experience.

I would rank carbon dosing as one of my least preferred methods for nutrient control because of the unknowns about organic carbon buildup and bacterial activity. It may also, in applications for ultra low nutrients. actually starve corals leading to the addition of expensive supplements to put back in what the bacteria have metabolized. In my case, it is useful as a supplement to some of the other methods which also have ups and downs..It was the last method I added and did so with some reservation and in moderately low amounts. . I still watch it closely.It is inexpensive and easy to do . It is also easy to overdo it in pursuit of 0ppm NO3 and PO4.

Chaetomorpha refugia are great in my opinion. They add oxygen ,use CO2, make a nice habitat for pods and such and you prune away nutrients. Unfortunately a large amount of well lit surface area is needed to handle a large nutrient load.

Granulated activated carbon is a very good exporter of certain organic compounds. Other absorbing resins such as Sea Chem's purigen may help since it may take up different types of organic compounds than the gac. These methods will obviously remove materials before they turn into inorganic forms of nitrogen and phosphorous. Downside might be depletion of certain minor or major trace elements which should not be an issue with regular water changes and /or feeding. They will not remove inorganic NO3 and PO4.

Skimming removes some organics although it seems not as many as once thought but it certainly aerates the water.My skimmers are much funkier when carbon is dosed.

Sand beds can become detritus traps and if not maintained well deep beds can become problematic in few years or less.

Live rock is a mainstay with no downside (other than new uncured or partially cured rock will contribute nutrients) I can discern in nitrification and denitrification but it may not carry the whole load and does nothing to lower phosphate.

Ozone with gac may help remove total organic carbon but is difficult to use and can be quite harmful to the reef and the aquarist if not well managed.

Granular Ferric oxide works very well in removing phosphate. It is expensive . It may also bring PO4 levels down very quickly which may harm certain corals.

Aluminum based phosphate absorbents are a bit less expensive and work but they may release unwanted aluminum ,especially if not well rinsed and filtered.

Lanthanum chloride will precipitate inorganic phosphate very well. It is relatively inexpensive. Using it requires careful filtration via sand filters or small micron media and some lathanum is still likely to go into the aquarium with unknown consequences longterm.

Sulfur denitrators work well to bring down high levels of nitrate in a relatively short time in my experience. They can be quite expensive unless you diy one. They will add sulfate to the water and will lower alkalinity and ph a tad which can be fixed with a little baking soda. They require careful monitoring to avoid issues with hydrogen sulfide,however.

Just a little context for the discussion since a decision on wether or not to dose organic carbon requires some comparison to alternative or complimentary methods for nutrient reduction ,in my opinion.

 

[Genetics]

<a href=showthread.php?s=&postid=15558591#post15558591 target=_blank>Originally posted</a> by HighlandReefer
Role of elevated organic carbon levels and
microbial activity in coral mortality
http://phage.sdsu.edu/research/pdf/Kline - DOC and coral death 5-24-06.pdf

Off topic but this is a very good article aside from a few grammatical/numerical issues. One point I would like to make on it is that they used seawater for the studies in which they spiked with a labile DOC (sugars). I did not see where they specified the concentration of the seawater POC or DOC levels which is a huge factor in outcome of the experiment. Potentially they added kindle to flames that caused a major event with the DOCs of the seawater. It would be interesting to see what would have happened if they would have introduced the corals after the initial event and what the DOC levels were before and after addition at timed intervals. Also, they mention bacterial additions of 10e6 per mL leading to 100% mortality. We also dose that to drive down nitrates.

Scooter, I like the idea but who do you measure how much is leaching through the sand into the water? FWIW, both processes are probably occurring within or reefs and may explain why every now and then a BB cannot get complete nitrate depletion.

Bertoni, you make some pretty good arguments with #1 and #3. Corals are incredibly sensitive to the type and amount of bacteria growing on them. Higher bacterial populations have been associated with White/Black band diseases. Which corals are affected negatively may be influenced by the organic used.

One constant theme I've noticed though with many tanks that have had negative results is using too much too fast. I see this often with sugar dosing with the recommendation of adding 1 tsp per 100g per day. Looking at the paper linked above it says there is an increase in coral mortality by 30 days. No surprise people are amazed at how great sugar additions work for the first week in dropping nitrates but then start to see a gradual decline in coral health. However, adding fractions of tsp per 100g usually helps to correct the nitrate problem without the coral mortality.