Activated Carbon Question

[fullmeal88]

I treat my tank with vodka, or at least i just started and am currently on day 3 dosing .3ml for my 70 gallon tank(net water volume). I noticed a flatworm problem in my tank the other day and grabbed some Salifert Flatworm eXit to kill them with. The directions state that after dosing you need to run activated carbon in the tank. I know that both the activated carbon and the vodka use up the oxygen levels in the tank so I had a couple questions.....

1. Will adding the activated carbon while dosing with vodka deplete too much oxygen in the tank?

2.Vodka as far as Ive read acts as an organic carbon, can dosing vodka replace the activated carbon for the flatworm eXit?

Thanks!

 

[TheH]

Where have you read that activated carbon consumes oxygen? I was not aware of that.

 

[fullmeal88]

You know I forgot where I learned that, but I know it does. Also vodka acts as an organic carbon which absorbs oxygen, so it would even make sense for an activated carbon to absorb oxygen levels.

 

[BeanAnimal]

<a href=showthread.php?s=&postid=13410407#post13410407 target=_blank>Originally posted</a> by fullmeal88
Also vodka acts as an organic carbon which absorbs oxygen, so it would even make sense for an activated carbon to absorb oxygen levels.

I am not sure where you heard that... but it is not correct

Vodka is not anything like activated carbon, nor does it act anything like activated carbon.

Activated Carbon is extremely porous. It attracts many compounds via Van der Waals force (similar but not the same as ionic bonding) and stores those compounds in its huge surface area.

Vodka simply causes in instant algae bloom that can then be mechanically or chemically exported from the system. The concept is that the vodka causes the bloom IN the water column before the nutrients can fuel algae ON the aquarium surfaces or bind to other molecules.

Hope that helps some

 

[BeanAnimal]

<a href=showthread.php?s=&postid=13410023#post13410023 target=_blank>Originally posted</a> by TheH
Where have you read that activated carbon consumes oxygen? I was not aware of that.

Yes wet activated carbon absorbs oxygen from the air. I would therefore assume that it will also pull it from the water column. Also not that the organic material that is trapped in the carbon will also depelte oxygen as part of the decay process. Is it enough to worry about in your aquarium. I doubt it. The folks over in the chem forum can quantify the numbers though.

 

[BigJay]

I've never heard of activated carbon taking oxygen from the water column.

I suppose it's possible to have a bacteria bed on the activated carbon feeding on the trapped organics and thus taking up oxygen. But is it possible for O2 molecules to get adsorbed by carbon?

 

[Michael]

this may help

http://www.hallman.org/filter/gac.html

 

[JHemdal]

BeanAnimal,

Re: "instant algae bloom" - Alcohol typically serves as an energy source for bacteria first. These can then be exported via the skimmer. Any subsequent algae growth comes later on. It isn't an instant process, but can be pretty quick given the doubling time of the various organisms. I've seen bacterial blooms within 8 hours of adding ethanol to a tank. This can take place in the absence of light (flashlight fish tank) so phtosynthesis isn't part of this. I've seen acute oxygen depletion when adding ethanol (as a solvent for praziquantel - which I don't do any more) - caused by bacterial utilization.

Jay

 

[BeanAnimal]

Jay,

Thanks for the post and helping to clear up what I left out.

I guess I should have qualified "instant" in relative terms with regard to the typical process in our systems. I can see how my post may have given people the impression that "instant" meant time measured in seconds, not hours.

I also neglected to to clarify that the process can consume considerable amounts of oxygen.

 

[fullmeal88]

So final verdict? Don't dose activated carbon while vodka dosing?

 

[Randy Holmes-Farley]

I do not see any reason to stop using GAC if you dose vodka.

 

[Michael]

personally im totally confused by vodka, no doubt it must work as many reefers say so, this is what this hobby is all about, letting others know about progress, however i just dont get the vodka thing even though ive read countless threads and articles, its just seems ridiculous to me, but hey i love to learn new things, however i wont use vodka on my tank

 

[miwoodar]

I agree with Randy (but then again, I don't think I have ever *not* gone with Randy's opinion on anything).

Michael - why does vodka seem rediculous?

 

[Michael]

<a href=showthread.php?s=&postid=13417171#post13417171 target=_blank>Originally posted</a> by miwoodar
I agree with Randy (but then again, I don't think I have ever *not* gone with Randy's opinion on anything).

Michael - why does vodka seem rediculous?

as i mentioned ive no doubt it works as many use it, but i just dont get sticking alcohol in the tank can help anything, its just obvious it does but i just cant work out the chemistry side of it, i mean how does it actually work, and more to the point who the hell discovered it in the first place, did someone accidentally spill some in their tank:lol: i mean why vodke, what about scotch or brandy etc, i just dont get it

 

[miwoodar]

I don't know who discovered it in the aquarium trade. I remember the first time I read a discussion on carbon dosing though. The subject was sugar. My first impression was that people were dumber than rocks for believing in such a thing. The chemistry side of it, well I can't tell you how that works. I imagine that the claims of nitrogen and phosphorus compounds being utilized as building blocks (DNA for one) by the bacteria is a good start though. Are the bacteria actively breaking down the NO3 and PO4 too? I imagine so. What is beyond there is beyond my little brain.

I work closely with many of the first persons to apply carbon dosing in the context of cleaning up hazardous waste in ground water. People in the industry used to laugh at the idea and ended up years behind the times. My company cleans up spills that would have traditionally taken 30 years in only 5 or 10 by pumping a few hundred thousand dollars of molasses into the ground....saving millions. We've used about a dozen different carbon sources. Molasses is most commonly used simply because it is usually the cheapest to use on a large scale. (I would not put molasses into my tank! Too many impurities and it's high in sulfur compounds!) We understand some of the processes as to how it works but unknowns definitely exist. We're growing bacteria just like reefers do...some of the bacteria happen to have the ability to break down chlorinated solvents.


fullmeal88 --- did the Flatworm Exit work?

 

[fullmeal88]

Havent used in on my personal system yet. Wanted to be sure it would be ok with the vodka treating however, I did treat in in my store (no vodka) and yes it worked very well!

 

[ChuckLawson]

<a href=showthread.php?s=&postid=13417223#post13417223 target=_blank>Originally posted</a> by Michael
as i mentioned ive no doubt it works as many use it, but i just dont get sticking alcohol in the tank can help anything, its just obvious it does but i just cant work out the chemistry side of it, i mean how does it actually work, and more to the point who the hell discovered it in the first place, did someone accidentally spill some in their tank:lol: i mean why vodke, what about scotch or brandy etc, i just dont get it

Why vodka instead of scotch or brandy (or gin, my personal preference ) is that vodka (the unflavored varieties) is pretty much nothing but pure ethanol and potable water, so you're not getting any surprises.

The chemistry side of it (this is the trivial "I never took chemistry" version I think I understand ) is that bacteria require organic carbon, nitrates and phosphate -- most of us have an abundance of the latter two in our tanks, but not much of the first. Adding a carbon source (vodka, sugar, etc.) allows the bacteria to multiply and use up our nitrates and phosphates in the process, to hopefully be skimmed out by the skimmer, thus exporting the nitrates and phosphates.

I've been trying it and it works; I hit the "I can't get anything reliable on my test kits" stage last week, but still had a cyano outbreak. I upped the dosage another notch last night, and I'm pleased to report that there's only about 25% of the cyano left today. Color me convinced

 

[Michael]

<a href=showthread.php?s=&postid=13418765#post13418765 target=_blank>Originally posted</a> by ChuckLawson
Why vodka instead of scotch or brandy (or gin, my personal preference ) is that vodka (the unflavored varieties) is pretty much nothing but pure ethanol and potable water, so you're not getting any surprises.

The chemistry side of it (this is the trivial "I never took chemistry" version I think I understand ) is that bacteria require organic carbon, nitrates and phosphate -- most of us have an abundance of the latter two in our tanks, but not much of the first. Adding a carbon source (vodka, sugar, etc.) allows the bacteria to multiply and use up our nitrates and phosphates in the process, to hopefully be skimmed out by the skimmer, thus exporting the nitrates and phosphates.

I've been trying it and it works; I hit the "I can't get anything reliable on my test kits" stage last week, but still had a cyano outbreak. I upped the dosage another notch last night, and I'm pleased to report that there's only about 25% of the cyano left today. Color me convinced

ethanol? thank you for that info, i will google that and try to get some info from it later, thanks for the reply

 

[fullmeal88]

So its working well for u ChuckLawson?

 

[ChuckLawson]

<a href=showthread.php?s=&postid=13421302#post13421302 target=_blank>Originally posted</a> by fullmeal88
So its working well for u ChuckLawson?

It seems to be; it's early days yet, though -- I started dosing the vodka a month ago tomorrow. Unfortunately, it's hard to quantify exactly how well it's worked -- I've got three nitrate kits (IO, Salifert, and API) that read all over the board (IO and API read zero now, Salifert reads 10 -- but it also reads 5 on brand new water made up with zero TDS RO/DI), and my phosphate kit has read zero for several weeks.

I've been proceeding just on observations the past two weeks, and in that time I've gone from hair algae and a growing cyano problem to (as of yesterday) virtually no cyano, but a bit of green turf algae. My plan is to keep stepping up the dosage (slowly) until either it all disappears, or I see a problem.

I've also been dosing Prodibio BioDigest once a week.

This tank was started with 95% dry reef rock about three months ago; I suspect that part of the reason the algae got out of hand so fast is that there was no pre-existing denitrifying bacteria in the dry rock. I've just set up another tank with established rock and sand, and have started dosing vodka on it as well, since I've got a bit of green film algae going in it -- it'll be interesting to see how it progresses compared to the other.