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FAQs about Dosing Carbon and Marine Systems

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Biopellets; reactors     4/24/18
Good afternoon Bob,
<Hey John>
I was wondering if you had an opinion on whether or not a recirculating feature on a biopellet reactor was really all that important?
<Well, such a feature (recirculating) can be of use w/ any media feed... promotes more dissolving (so absorption), better for folks who want "more">
I built a really nice pellet reactor for my 750 gallon. It’s 6” x 22” and all acrylic. It’s busy a basic down draft style via external pump and then the effluent just exits the reactor. Would there be a benefit of investing the time to convert it to a recirculating style?
<Being an experimental sort (and a cheap skate) I'd try yours as is... Maybe consider modifying later>
As always, thank you.
<Thank you for sharing. Bob Fenner>
Re: Biopellets    4/24/18

Cool. Thanks Bob. Hope the knee is on the mend.
<Thank you John... a bit more; and am (finally!) in to see my primary today. A litany (written list this time) of questions, concerns. Cheers, BobF>

Drunk Sharks?!   7/4/11
Good Morning Crew!
I am about to overhaul and upgrade my 180 gallon system to a 400 gallon system with a 180 gallon tank, a 100, a 90 refugium, and a 20-30 gallon wet/dry sump (the 400 does not include hang on filters or plumbing naturally). I would like to put a whitespotted bamboo shark in my 180 for about a year or so two at the absolute most.
<Mmm, start w/ a very small specimen... feed very sparingly... not easy for any shark, chondrichthyous fish to "turn around" physically, and even bamboo sharks get excited from time to time... can damage themselves in such small rectangular spaces>
At which point I will be building a 700-900 gallon tank. My issue is that I do something rarely recommended by anyone, vodka dosing. Its been very successful and I'd very much like to continue the dosing but if there will be a problem with the small shark (approximately eight inches at the moment
and still at the store) then I will have to decide.
<Well... I am not a fan of this practice being done on a continuous basis... but IS of value/utility on a punctuated, time to time use>
Idealistically I'd just like to alter the acclimation process accordingly.
I have been reading for days here on sharks and have purchased the book which is on its way. I'm very excited at the potential to have such a beautiful shark that will hopefully have as much personality as the
rest of my fish if not more. Please tell me if it can work out with the vodka dosing.
Thank You
<Can... Bob Fenner>
re: Drunk Sharks?!   7/4.5/11

That is great to hear, or see. I am looking into purchasing the recommended Lugol's iodine
<Mmm, commercial Iodine/ide ones are vastly superior>
solution but the problem is there are two dilutions! There is one with 4% potassium iodide and 2% iodine (not the one I want I am assuming).
<Could be...>
Then there is one with 7% iodine and 2.2% iodine.
<Mmm, summat wrong here>
I saw the post with the recommended half ml. per week but for which dilution?
<Would have to see/read the excerpt... Of course, depends on what you're starting w/ as a stock solution>
Also since my book has yet to arrive I am unsure of whether the recommended vitamin supplements are in it. If they are there is no need to respond I'll find them shortly. But if the items are not listed then would you please point me in the right direction?
<Posted on WWM: http://wetwebmedia.com/marine/fishes/FishInd1.htm
scroll down to Sharks, Foods/Feeding/Nutrition FAQs>
As for my current system and menagerie, I would like to try Gamma Nutraplus Reef Feed but I cannot find a distributor.
<Have your LFS's (local fish stores) contact Quality Marine, LA>
I found limited information at Tropical Marine Center and perhaps I overlooked a link to purchase it there. It isn't even available on eBay.
<TMC is the maker/manufacturer, QM is their principal US distributor>
Thank You once again for providing optimal brain-picking!!
<Welcome. BobF>

NPX Bio Pellets    6/16/11
Hi Bob,
Could you post this in the dailies so others will learn from my experience.
<Will definitely do so. Thank you for the input. BobF>
If you are considering using the Two Little Fishies Phosban Reactor 150 for dry vodka dosing, choose a pump of at least 350gph. A MaxiJet 1200 or other similar gph pumps will not be strong enough to tumble more than 150ml of pellets. If your system only requires 150ml or less, the MaxiJet will be fine. This reactor can handle a maximum of 300ml of pellets and a stronger pump will be required. I recommend the Mag Drive 3 for this purpose.
Never start with the full dose of pellets (100ml per 25 gallons recommended) or within three days you will have a bacterial bloom like you have never seen before. This is more prone to happen in systems with
nitrate levels exceeding 20ppm. Always start with no more than half of the recommended dose. After four weeks you can gradually add a little more every week until you reach your maximum dose. Do not add more pellets if the water is slightly cloudy from a bacterial bloom, it will likely get worse, wait until the water clears.

Carbon Dosing (and other husbandry practices) -- 01/22/11
Thank you for taking the time to help me understand what may be going on in my aquarium.
<<Is my pleasure to assist>>
First, my setup: 55 gal display with a beach sand and crushed coral substrate at a depth of 4 inches; approximately 75 pounds of live rock, a 20 gal sump comprised of three compartments of approximately equal volumes and populated with a protein skimmer, an activated carbon reactor, a refugium with live rock rubble and 6 inches of sand over a plenum constructed of pebbles, and 15 three foot red mangrove trees. Lighting is achieved by T5 fixture with 3 actinic and 3 10000K in the display and a 40 watt fluorescent grow light over the refugium. My livestock includes a one-spot Foxface rabbit fish, 3 damsels, a lipstick blenny, a firefish goby, 2 turbo snails, a mated pair of peppermint shrimp, several varieties of corals as well as all the usual lovely suspects aka bristle worms, peanut worms, brittle stars, amphipods, copepods, Stomatella, et al. What a privilege it is to be witness to the many miracles of life this hobby affords the involved aquarist!
<<Indeed this is so>>
In the past two weeks I've been witness to a nocturnal birth of hundreds of peppermint shrimp literally filling the tank with transparent little offspring not long for this world and then days later the daytime spawning of a Stomatella spewing gamete into the water currents while a 3 stripe damsel consumed as many of them as possible. Amazing!
Here are my parameters:
Nitrates: undetectable with my testing equipment
Phosphates: undetectable with my testing equipment
Ammonia: undetectable with my testing equipment
Nitrites: undetectable with my testing equipment
KH: 214.8 ppm
Calcium: 420 ppm
Magnesium: 1250 ppm
pH: 7.96 low point to 8.2 high point through the diurnal cycle
Water temperature: 79 F
Salinity 34 PPT
<<There are arguments for having very small amounts of NO3 and PO4 available in a reef aquarium'¦and it's likely some of each 'is' present, though like you established -- undetectable with your testing equipment>>
I supplement nightly top off water via a Kalkwasser reactor. Further, I dose with calcium, soda ash, and magnesium to maintain commonly accepted parameters.
I perform a 5% weekly water change with RO and DI water that has been aerated for a minimum of several days and vacuum during the change. I feed the livestock once daily only as much as they will consume in 5 minutes or so and then actively remove any leftover.
<<Here we disagree - I am a firm believer in feeding one's livestock/system well (minimum of two 'healthy' feedings a day of a variety of foods). I feel many a fish's long-term health, indeed their lifespan, is compromised by inadequate nutrition in home aquaria>>
I skip feeding once or twice weekly.
Everyone seems to be growing, active, colorful and healthy. In the words of John Prine "Everything is Cool".
<<On the surface, anyway [grin]>>
After the cycling process of the aquarium I was plagued, as many are it would appear, with a high level of nitrate that appeared unmanageable with water changes alone. Therefore, I commenced a carbon dosing regimen which proceeded over the course of a month and a half with superior results. I dosed from September the 12th at 80 ppm nitrates until the last dose on October 25th and undetectable nitrates.
<<Though not without danger, carbon dosing 'can' be very useful>>
I continued to half the carbon dosages until the addition of vodka was negligible. As one would expect the skimmer went into overdrive and produced a significant amount of skimmate during the carbon dosing regimen.
<<The increase in bacteria count>>
However, here is the interesting part and the source of my question. Why then after 3 months have not the nitrates reappeared since I have ceased completely the maintenance dosage of a supplemental carbon source?
<<This would seem to indicate your system has reached a 'balance' re its biological filtration vs. nitrogenous compound input/production>>
Further, why is my protein skimmer now producing minimal amounts of skimmate?
<<For the same reason(s)>>
Could it be that those "lovely" red mangroves are doing the job I hoped they would and are exporting a significant amount of nutrients from the water column?
<<Is possible'¦though not the best choice for Nitrate/Phosphate reduction since they grow/uptake nutrients more slowly as compared to Caulerpa or Chaetomorpha alga species, the large number you have employed may well be sufficient for your current husbandry practices>>
Thanks for reading.
<<Thank you for sharing'¦ EricR>> 

Re: pH emergency? & Vodka dosing   1/7/11
Thank you for the words. I didn't mention it, but I have been siphoning/vacuuming the substrate in the main tank too, and will continue to do so. So far I have changes out approximately 50% of the water in 48
hrs, and will be doing another 20% change tomorrow.
<You may need to do a few half change-outs in time...>
As always, appreciate the help (and the words of wisdom). Along those lines, did I read that you are not a fan of the "vodka method" for battling hair algae?
<I am not for most cases, individuals... Unfortunately such carbon dosing calls for more caution than the majority of folks are willing to apply. Given care however, manipulating C availability can be of use. BobF>

Dosing Vitamin C and Vodka plus other beneficial vitamins 11/08/10
Dear Crew,
Not to send the same email twice since I knew you were short handed but I hadn't got a response and didn't see my email posted on the daily faqs.
<Mmm, I haven't seen it either>
I have added my first email below. To make things short I really would like to know more about what vitamins I can add to the tank directly to the water column that would benefit my fish. I know Selcon is a good food soak but I am more or less just wanting the "safe" versions of the vitamins I could actually add to the tank that are tissue soluble. I would like to add more B vitamins B1, B6, and B12 I am aiming at offsetting any deficiencies my predatory fish might have. I am giving them a varied diet but just want to do more. Previous Email Dear Crew, I had decided to undertake vodka dosing to try and maintain a low nutrient system for my saltwater aquarium. I have a mostly fish only tank with a few frags here and there of mushrooms but that's it really. My intention of writing this article is to discuss some things I have encountered and some things I would like to know more about. First off my tank parameters are as follows: 180 gallon glass tank, 38 gallon sump, protein skimmer, and a total estimated water volume about 175 gallons with rock displacement. Fish include 2 blue tangs, yellow tang, spiny box puffer, snowflake eel, 4 yellowtail damsels, 2 domino damsels, dwarf zebra lionfish, niger trigger, dog face puffer. Water parameters are 0 ammonia, 0 nitrite, undetectable nitrate, phosphate between 0 - 0.5 and salinity 1.27. Now previously to dosing vodka I was at 40 ppm nitrate. In three weeks I was at zero. Now I know that the results of vodka dosing are well known so I won't elaborate too much on how it works. I will state that I still make water changes weekly just smaller amounts 10 gallons and this should only be used as a part of the solution and should not be a main solution for water problems. What I do want to discuss is the Cyano outbreak that often occurs with vodka dosing. I encountered this and instead of using Microbacter 7 as well with my dosing as a lot of people on reef central have suggested I went with another approach. I instead started dosing vodka and vitamin c (sodium ascorbate) combined together. Most people use Vodka Sugar Vinegar in an effort to hopefully target multiple types of anaerobic bacteria growth. However I thought to myself why not pick another carbon source that is beneficial to fish as well. So I started dosing 1 tbsp of vitamin c and 5 ml of vodka twice a day 1 time in the morning and then once right before bed.
I never raise the dosage because unlike others I believe just a steady continuation provides enough continual bacteria growth to eventually achieve the results I desired. Now I want to state that I was at zero nitrates before the vitamin c addition but had problems with Cyano. After adding vitamin c the Cyano was gone after about a week. Since I have continued this same dosage daily and have not only seen better water clarity but better fish behavior as well. My fish are more alert and out in the open almost 3 times as much as they used to be. Noticing this change makes me wonder as well what other vitamins could I supplement the tank with that is tissue soluble that would benefit the fish as well? I know there is vita chem and Selcon but buying vitamins from iherb.com are much more financially feasible for long term use. I have read that Vitamin B1 and B6 will give fish more energy, jumpstart their appetite, and offset the vitamin deficiencies they go through sometimes. This is slightly counter acted with varied diet but if even better results could be achieved why not take it to the next level. I would really like your opinion on this. Also it might benefit others as well to know that for about the price of 1 Selcon bottle you could increase your aquariums vitamin intake for 2-3 months with about 3 times the vitamins daily that Selcon would provide. Keeping in mind your bacteria population was at the dosage level you were dosing at as to not cause a bacterial bloom. The only concern would be whether you dosed through food or directly into the aquarium.
<Mmm, well, both end up in the water, and the livestock to degrees>
Directly into the aquarium would obviously yield less results then food soaking unless you dosed frequently enough to avoid the dilution of the vitamins. What is your take on this as well as whether I continued this?
<Soaking foods is preferred as you state, in terms of getting more into the animals fed... Dosages... I'd need to be home (am out visiting) to look up in in-print references. For practical purposes, it is very rare that hobbyists overdose water soluble vitamins... Esp. vitamin C is very safe to add in large doses. Bob Fenner>

Carbon Dosing - Dosing Vodka into a Marine tank 9/17/2010
Hey Crew,
<Hi Jimmy.>
Recently I have been reading about carbon dosing reef tanks with vodka.
<It works, I experimented with it myself for a while, but....>
I understand the risk of "overdosing" in the early goings and the potential problem of bacterial bloom and oxygen depletion.
<Oxygen depletion is the risk, the bacterial bloom is what depletes the oxygen.>
Is there a direct toxicity to fish from the vodka?
<None that have been observed, as far as I am aware. You would have a massive, oxygen depleting bacterial bloom long before you could dose the tank to the point where you would alcohol poison your fish.>
Another question concerns long term adverse effects. There seems to be much less written about this topic.
I understand that once nitrate and phosphate are depleted or close to depletion, overdosing can be an issue, but other than that, what can go wrong with carbon dosing in the form of long term complications ?
<Soft corals do not like vodka dosing, mushrooms tend to shrivel up and die. It can also cause a bloom of Cyanobacteria. (Red slime) These were the reasons that I stopped using it. It does 'burn up' the nitrates pretty quickly though You would have to very closely monitor your nitrate levels and adjust your dosing rate regularly.>

Dosing Vodka for Nitrate/Phosphate Control -- 11/07/09
Hi Crew:
<<Hello Bonnie>>
I just read an article on Reef Central about dosing vodka in a reef tank for nitrate and phosphate reduction.
<<Mmm, yes'¦have done this myself>>
They say you can accomplish the same with other carbon sources such as sugar or vinegar, but the method they explain uses vodka.
<<Indeed'¦ The ethyl alcohol in the vodka provides a concentrated and easily measured/dosed source of relatively clean carbon>>
Here's an excerpt from the article "The addition of vodka/ethanol is thought to increase bacterial biomass. For this, vodka addition would result in bacterial growth and reproduction. During this process nutrients in the water (including NO3 and PO4) are taken up for the formation of new macromolecules that are needed in cell synthesis and viability. Due to this rapid growth and reproduction, NO3 and PO4 can drop quickly from detectable levels by most test kits on the market. The increased biomass of the bacteria leads to a notable increase in skimmate production, removing more waste than without vodka addition. The increased skimmate is thought to remove the bacteria or bacterial byproducts that have assimilated the NO3 and PO4 within the water column leading to NO3 and PO4 depletion."
<<Agreed'¦ Though I also wish to point out that this 'process' consumes an enormous amount of oxygen (due to the increase of aerobic bacteria/activity)>>
They only recommend this method for people who have "good" protein skimmers attached to their tanks.
<<Reference my previous statement>>
Of course, they warn to proceed very carefully, monitoring nitrate and phosphate levels in the tank daily. Basically, you are to dose a small amount of vodka each day, increasing it each day, measuring the nitrate and phosphate levels, until you begin to see a drop in these levels. Then you are to continue using the same dose (as a maintenance dose) from then on. I was just wondering what your thoughts and/or experience, if any, are with implementing this method?
<<There are those that will swear by this method/process, and others that don't like it at all'¦and I admit to using it when battling Cyanobacteria. But, the procedure is not without risk'¦ I once lost several thousand dollars in fish and mature coral colonies when a GFCI tripped, shutting down my sump recirculation pump shortly after dosing Vodka right before lights out (and my going to bed). With the loss of water circulation, and the resultant segregation from the display of my skimmer, the bacterial bloom robbed the display of oxygen. I awoke the next morning to a tank of piscine corpses (save a few surprising exceptions)'¦the damage to the corals was not apparent right away, but rather was to manifest in the weeks and months that followed. I have since limited the use of such 'carbon dosing''¦and I now have two sump pumps, on 'separate' circuits>>
They also warn that this method is NOT for everyone. You do have to be committed to adding the vodka every day in order to be successful, it's not a hit or miss thing, whereby one day you dose and the next day you forget to dose, etc.
<<Mmm'¦ Missing a day now and then is not a big deal in my opinion>>
Any thoughts would be appreciated.
<<As stated'¦ The procedure 'can' be useful, but is not one to be taken lightly. Do weigh your perceived advantages re'¦and proceed very cautiously should you decide to go forward with it>>
As always, thanks for your assistance and advice.
<<A pleasure to share'¦ EricR>>

Sulphur with a carbon source... Tricky Q's re denitrators  - 10/06/2009
Hi my name is Steen... i have more then one question, but they are related, so here goes...
I read an article that you can start up the bacterial culture in a sulphur reactor much quicker by dosing vodka, and just letting it recirculate for 3 days (can't find the article again, REALLY annoying!). I can't really find the information i want anywhere, and i have posted a similar thread on a LOT of forums, no useful replies! I want to dose a carbon source and run a sulphur reactor at the same time:
1) Would it be beneficial to dose it slowly through the sulphur reactor?(diluted form dripping slowly into the reactor intake)
<IF carbon is limited...>
2) Would it work kinda like a combined carbon based reactor with a sulphur based?(i don't know enough about the differences in the cultures living in carbon based and sulphur based reactors)
<Mmm, not if I understand your question... No... the ethanol will only further chemically feed the sulphur-based bacteria>
3) What possible Long term effects could there be when combining them?(the sulphur beads getting covered with a culture living of the carbon and thereby not utilising the sulphur)
<Mmm...Combining the C2H5OH? When something becomes rate-limiting... reaction series will slow>
4) Is the RedOx the same in both types of filters?
5) What difference would there be between using VSV and vodka?
5.5) My skimmer is acting strange after i started, most of the time it does absolutely nothing, and some times it just go crazy, not like more 'dry' foam being created, just the water/foam level rising and overflowing the cup in no time!?!?
<To be expected>
Hope you can help me out with some information on the subject(s), and if not then thx 4 your time anyway :)
p.s. I actually started 3 days ago to dose 30ml vodka a day very slowly into my 18kg sulphur reactor(cleaned 3 weeks ago, so not really matured yet, trying to keep it around -170mV) for my 900l tank which also runs a reactor with 1000ml Rowaphos and a reactor with carbon and shuran150 skimmer...
<I'd reduce this to 10 ml.s maximum. Bob Fenner>

Re: sulphur with a carbon source   10/7/09
i Bob, first of all thanks for your answers :) So what i get from it is that if carbon isn't a limiting factor there'd be no advantage in dosing it trough the sulphur denitrator,
but you would limit it to 10 ml 37% vodka pr. day in a filter containing 18kg sulphur beads, why is that?
<IF there is too much Vodka added (beyond the metabolic use of the microbes in the denitrator) the excess can/will go on and have "other adventures" in a system... the lesser of which are (usually green filamentous) algal profusion. 10 ml.s is likely about the limit of good you can do here. If you had/have diagnostic tool/s for determining excess hydroxide concentration, I'd actually measure/monitor... though you will very likely find that the "use" of ethanol vacillates...>
If i dose it, still keep the ORP/RedOx potential between -100mV and -200mV.
<Too low... for the main system. Are you stating for the reactor discharge water?>
Could there be an increased risk of clogging the sulphur denitrator if dosing into it?
<Yes; slightly>
I hoped that like carbon based denitrators that use bioballs, the sulphur beads and aragonite would provide the surface area for the bacteria to grow on when dosing vodka, but that would not be the case. And using pure vodka has no advantage over VSV other then being more expensive, since sugar and vinegar are really cheap!(any drawback with VSV?)
<None that I'm aware>
Have you heard about 'quick restarting' a sulphur denitrator with a carbon source?
<I have, and discount it/this. In most any established system there is sufficient carbon in place to initiate denitrification in these units w/o supplementation. I would make an equivalent statement with the forward reactions of nitrification and presence of sufficient nitrogen compounds.>
and again thanks for the advice you've already given, and thanks for your time..Happy Landings... Steen..
<You too. BobF>

FW: sulphur with a carbon source   10/7/09
Hi the unit is behaving totally weird now, it fluctuates A LOT when power i disconnected
<!? I would NOT disconnect power here... like "the spice" (Dune/Herbert), the water must flow>
and connected, so by disconnecting it i can get any value i want, plug it back in and everything looks all right, except the aquarium ;) ... I have tested it on a solution with a known RedOx and it indicated -40mV
<Danger! You do NOT want negative ORP>
in a 300mV solution, problem is that i costs me 40 dollars to receive the package every time, because it is from outside the EU and 15 to send, so if i send it back and you repair the unit at you send it back to me, it will cost me 95 dollars in total excluding the price of the unit, don't really know what to do here, hope you can help me somehow...
<? Am not following you... What package? Media/stock feed? BobF>
FW: sulphur with a carbon source
sorry mate, was not intended for you, my RedOx unit is broken :)
<What a relief! Of life, living things in our world, we don't want negative ORP. Cheers, BobF>

Re: sulphur with a carbon source  10/9/09
Hi Bob and again thanks for your answers, one last thing:
IF there is too much Vodka added (beyond the metabolic use of the microbes in the denitrator) the excess can/will go on and have "other adventures" in a system... the lesser of which are (usually green filamentous) algal profusion.
What would be the deference between some of it 'escaping' from the filter, and me just dosing it straight into the tank like in: http://reefkeeping.com/issues/2008-08/nftt/index.php
A landing you can walk away from is a good landing, an aquarium you can't walk away from is a good aquarium ;) (okay im getting a bit cheesy here :P )
<I would avoid directly dosing ethanol into an up and going system in any great quantity/concentration... Much better to drip feed directly into the denitrator. B>

Re: Tank and stocking questions, C dosing   10/19/09
Hi again Mister Fenner or whomever I am writing to.
<Hey John! JustinN here today!>
I hate to be a pest but I have a question about my lunare wrasse. He has an off colored non symmetrical grayish patch near his abdomen on one side.
<Mmm, possibly/probably a side effect of previously mentioned chemical irritation>
He is very active and eats very well. His food is soaked with Selcon and VitaChem mixture. He flashes more than the other fish probably due to the vodka dosing as we discussed earlier.
<This would be my guess as well>
His off colored spot is not bleeding and does not appear to be a wound of any type. I tried to photograph him but he is too fast.
<That they are!>
It sort of reminds me of when I used to fish all the time and would scale my catch. It appears kind of like a decent sized patch of scales are missing.
<Mmm, yes, likely a side effect of the flashing earlier described -- is quite likely exactly what you are witnessing.>
Should I empty the 500 pounds of liverock, net him, and place him in the hospital tank or since everything else is great with him and he gets fortified food twice day, should I just leave things as they are. Thank you very much as always for your advice.
<Perhaps the Vodka dosing is too high of levels for your livestock? As Bob previously mentioned, you may need to back down on the total dosage here a bit.. If the spot does not reduce, I personally would likely quarantine 'just in case' -- easier to medicate if absolutely necessary in a quarantine situation. Good luck! -JustinN>

Re: Tank and stocking questions  10/12/09
Hi there Mister Fenner. I hope all is well with you. Nitrates are still in check and the tank is going splendidly. The new queen angel I introduced after quarantine is doing fabulous<ly>. The raccoon butterfly has already totally decimated my aiptasia and is eating everything I feed the others. I have one small concern though I would like to share with you. Several of my fish "flash" on the sand just using they're mouth and then swim away. This happens every so often throughout the day. This seems to have started after I removed the clown trigger that died and have increased my vodka dosing.
<... likely chemical irritation, not biological>
There is no sign of disease or abnormal behavior and they are eating like horses. I was wondering if the vodka could be irritating them causing them to flash
or should I be concerned about something else? All fish/rock arrived in the tank after quarantine so I know nothing should have been brought home. Please advise as to what you think/recommend. Much appreciated as always.
<Welcome. BobF>

Feeding Linckia with Carbon Dosing? -- 10/02/09
Hi to all the crew,
<<Greetings Owen>>
Firstly thanks for putting together such a great resource, it's helped me out many times.
<<A collective effort'¦we are pleased it has been of benefit to you>>
I've recently been doing a lot of research on blue Linckia starfish as I was thinking of getting one for me 50G reef.
<<Mmm, aside from this setting being too small and unable to provide sufficient substrate for grazing'¦I believe we still just don't 'know enough' about this animal for the casual hobbyist to attempt>>
I have decided against getting one due to the size of my tank meaning that I'd have to move it on to a friend's larger tank once it had grown.
<<It's much more likely my friend that it would never survive to be moved>>
One thing did occur to me when doing the research though and I was hoping somebody could either confirm or deny the logic of my thinking.
<<I'm happy to proffer my opinion>>
Linckia are generally thought to feed on bacterial films on live rock.
<<I think it is more accurate to state the bacteria film could make up a 'part' of this animals diet, but that it grazes on the 'surface' of the rock which is comprised of the afore mentioned bacteria film, sponges, tunicates, algae, emergent life forms, etc.. I'm highly skeptical that this creature could subsist on the bacteria alone>>
Carbon dosing in a reef tank increases these bacterial films as bacteria take up the carbon along with nitrates and phosphates.
<<Indeed'¦as well as available oxygen>>
Therefore a Linckia starfish will fare better in a tank that is being dosed with carbon than in one that is not (all other things being equal).
<<I dare say not'¦as explained>>
Does that make any sense?
<<Not to me>>
Is there any reason it wouldn't work (wrong sort of bacteria maybe)?
<<This too may be a factor'¦but more likely it just isn't 'enough''¦period>>
Would it be worth anybody with a starving Linckia trying carbon dosing as a way to increase available food?
<<I really don't think it would make much difference in the health/longevity of the animal; and if abused/utilized without due understanding and care, can prove hazardous to your other livestock. Better to provide a ready supply of 'new' live rock'¦a not inexpensive proposition>>
Thanks for reading,
<<Thanks for participating/sharing... Eric Russell>> 

Carbon dosing or Too Much Light? (I definitely don't think the latter here) -- 04/08/09
<<Greetings stranger>>
Have a good question about my 75 gallon sps reef.
About 7 weeks ago, I upgraded my lighting to a 7/54 watt T5 Aquactinics Constellation. I successfully have acclimated my corals (this fixture can cook sps on the sand bed of a 75, just didn't want to be forced to place corals high). Anyways, I've also been carbon dosing (vodka) about 1 ml of 80-proof per day in order keep phosphates and nitrates extremely low.
<<I do this myself from time to time'¦but is not without risk (I managed to wipe out $700 worth of fish when a GFCI tripped overnight after dosing'¦ and lost another $3,000 or so in corals in the ensuing months as the system tried to regain its "balance"). I hope you have some redundancy built in to your system to keep water flowing through the sump should a circuit/pump go off/out>>
Before I continue here are my parameters:
Temp: 80-81.5
Salinity: 1.25-1.26 (refractometer)
Calcium: 440-470 (API)
ALK: 8-9 (API)
Nitrates: 0 (API)
Phosphates: 0 (Salifert)
I do a 10 gallon water change every 7-8 days. I have a Remora-Pro with a Mag-5 that gets the job done (not amazing, but seems sufficient for my small bioload). I have a ton of flow (turnover is 45 times per hour).
The problem I'm having is with color. My corals look pretty good (a lot of color) but...they are starting to get very light in color. Not bleached, but if they were to get much lighter, they would start looking bleached.
I have two theories.
<<Let's hear them'¦>>
It's either too long of a photoperiod with this fixture (4 bulbs for 8 hours, all 7 for 4.5 hours),
<<Nah'¦ If anything this is too little. I prefer a good 12-hr photoperiod'¦more closely mimics that of the tropics where these animals are collected>>
or my tank is nutrient starved and is dying for a little phosphate and nitrate.
<<I think this to be much more likely, especially considering the carbon dosing>>
I'm thinking this is the key.
<<Is a good place to start>>
When I go to my LFS, I always get frustrated because his colors are better than mine with sub-par lighting. But his tanks have nuisance algae. Not tons of it or even enough to be an eye sore, but its there. He obviously has nutrients in his tank.
Mine is barren of nuisance algae, completely.
<<This seems to be the common goal of many/most hobbyists'¦even though a bit of algae is normal on the reef'¦and even of benefit re food/habitat for many of the smaller beneficial organisms in our tanks>>
I've heard people on Reef Central (that have great sps tanks) say that when nutrients are too low colors will fade, too rich and they get too dark or brown out corals. What do you think?
<<I am in agreement'¦and this is often a balancing act depending on the efficiency of your filtration and your husbandry practices. I've known of reef hobbyists who actually 'dose' Nitrate (generally in the form of Ammonium Nitrate) to keep their corals 'colored-up.' I would try dosing the carbon on a limited schedule and see what effect this has on your corals. It may take some time and experimentation to find the right combination of frequency and dosage. Or boost your feeding schedule/volume and see how this affects things'¦am sure your livestock will appreciate this last for sure>>
Thank you for your help!
<<Do let me know what you discover'¦ Regards, EricR>>

Re: Carbon Dosing or Too Much Light? (I definitely don't think the latter here) -- 04/09/09
Will do. I'm going to dump a can of flake in the tank right now....see if I can get some phosphates and nitrates going...haha.
<<There ya go!>>
Will let you know. Thanks for your help.
<<Cheers, EricR>>

Burnt Tips'¦ Help! (Carbon Dosing Issue?), Vodka use  12/10/08 Crew, <<Seth>> I recently decided that I was going to give carbon dosing a try... <<I do this'¦ Has some benefit, and some pitfalls'¦ Do proceed with caution>> Last week I dosed extremely small amounts of vodka in my tank for 5 days straight (about .4-.5 ml per dose in 75 gallon tank). <<This sounds like a good starting point. A good rule of thumb is 1ml per 100g of tank capacity>> My nitrate and phosphate levels have always been barely detectable or not detectable...but so many people have said the color drastically improves and they can get away with a lot more feeding when dosing vodka. <<Mmm, can be a useful adjunct'¦ But many things come to play in a reef system, if you are looking for a magic bullet'¦ This is not it'¦>> Last Friday I noticed my Blue tort Acro had some pretty irritated tips, almost looked like something had chewed on them or as if they were about to recede. I refrained from dosing Friday and haven't added another drop since. The only other SPS that looks different is my Birdsnest, which is showing a little less than normal polyp extension (today). At one point last week my water seemed to be a little cloudier than normal, but I don't think enough to be a bacterial bloom. I've read the water gets VERY cloudy during a bloom. <<Depends, blooms can vary in intensity/density. This may well have been an indicator to reduce the dosage>> The tips of the Blue tort don't look to be getting worse or better as of now. Is this what people call burnt tips from Vodka dosing? <<Cant say I've heard of this before. I too have Blue Acropora tortuosa, but have never experienced what you describe as a result of carbon dosing. The cause of this issue may be nothing more than coincidence, but if you think the dosing is malaffecting the corals then I wouldn't do it>> Here are my parameters Temp-80-82 Salinity-1.26 PH-8.2-8.3 Nitrate-0 Phosphate-maybe .1 it's hard to read on API test chart...but barely anything. Alk-7.5-8.5 DKH Calcium-440-460 Is there something that I might be missing? <<Maybe'¦ Have you considered that both Nitrate and Phosphate are required nutrients? Perhaps the carbon-dosing is dropping these levels TOO LOW and malaffecting the corals in this manner. The answer may be as simple as increasing feedings'¦ But this is only speculation on my part>> I haven't tested for Ammonia or Nitrite. They have both been undetectable since my cycle finished. Is this a possibility? <<How do you mean? As in an increase in Ammonia and Nitrite? I'm doubtful'¦>> Also should mention that a week and a half ago, I added some Candy cane coral and a small brain to the tank. This is my first LPS addition...prior I only have had SPS and some pulsing xenia. Could it be the candy cane or brain releasing toxins? <<Possible, but not likely in my opinion'¦ Issues with these type animals usually stem from too-close placement and resultant physical contact of some form (e.g. - extended feeding tentacles or Mesenterial fibers)>> Thanks for your help; you guys are the best resource on the web. Seth <<Thank you for the kind words'¦ Happy to share. EricR>>

Vodka Dosing -- 08/19/08 Hi -- <<Hello>> I've searched your site and a few others and read some interesting articles about the concept of vodka or ethanol dosing to reduce/eliminate Nitrate and Phosphate in reef tanks. <<Indeed>> Most of it was fairly dated however and I was curious as to whether the idea still has currency. <<Possibly, with caveats'¦ Firstly, this methodology is not without danger...the right combination of circumstances can be catastrophic (I speak from experience). Secondly, this method only treats the symptom and is not a cure-all for what ails your system re buildup of nitrogenous/organic compounds. Are you aware of how this method works? The premise is the addition of a concentrated form of carbon (Vodka/ethanol) provides a food source that promotes the artificially high production of certain strains of bacteria for a limited period (until the carbon/food source is depleted). Some of these strains of bacteria have the ability to 'double their populations every 20-minutes.' As this mostly aerobic bacteria population grows, along with the carbon source, excess nutrients are also oxidized. As implied by the name, this process is driven by oxygen consumed by the bacteria to drive their metabolisms'¦and therein lays the greatest danger in my opinion. Coupled with the wrong conditions (already low oxygen levels from overstocking, inadequate water movement, etc.) or unfortunate circumstance (loss of power/sump pump circulation) the artificially high bacteria population can rapidly consume all the available oxygen creating a severe anoxic condition>> I'm home in the middle of a vacation for a day or two and just tested my nitrates which are disturbingly high as I had to shut down my skimmer while I've been gone. <<Hmm'¦don't know what 'disturbingly high' is>> I was thinking that it might be a way to bring them down quickly and give me time to deal with it when I return home in a week or so. <<As stated, this method only treats the symptom'¦and then only briefly. One or two 'doses' before leaving the tank for a week or so will have little overall impact. I think your system would be much better served here by a canister filter filled with cut-up Poly-Filter>> So my questions are: 1) does it work? <<It can, yes'¦ I have found it especially good for removal of Cyanobacteria'¦after determining and attending to the initial cause/source of the outbreak>> 2) Should I do it in this circumstance? <<I would not'¦for reasons already mentioned>> 3) Can you suggest a dosage; <<Would rather not as I wish to discourage your use of this methodology>> and 4) are there any risks since I won't be around to monitor anything but the short term effects? <<I strongly urge you to find/use a different method to bring down your Nitrates in this situation. And the obvious'¦keeping the skimmer running and having someone check on/feed your system and empty the skimmer while you are gone. A week is too long to leave your reef system unattended, in my opinion>> Thank you for taking the time to share your most valuable experience and expertise. Eric <<A pleasure to assist. Eric Russell>> Ps disturbingly high is around 60-70 ppm <<Ah'¦yes indeed. I would confirm the validity of this test (new/different test kit) and if accurate, determine the reason/fix what is causing such a high reading'¦skimmer on or not. Regards, EricR>>

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