Randy's vinegar dosing limit. I found it!

[Dan_P]

Originally Posted by Dan_P

i have another answer. Jorg’s article was rejected by Reef Keeping and its rejection caused quite a stir online, especially when Reef Keeping critiqued the article but wouldn’t publish it. Now the search for the article got a bit more involved and interesting.

Still haven’t found an English version of Jorge’s article and he seems to have disappeared as a contributor on the old thread that I am reading. I may have to find the German article and get it translated.

As it stands now, the directions for dosing seem flawed after the second week. The flaw is that the larger the system you have, the less carbon you are advised to dose per gallon. This might explain some of the variability in the carbon dosing sucess rate. The bigger the system you have, the greater the probability you underdosed, though I am still not clear what the science is that supports the dosing rate. I believe the notion of carbon dosing came from commericial aquaculture. One approach called the Belize method selects a carbohydrate addition rate that corresponds to the amount of protein in the feed, i.e., the nitrogen input. The logic of the approach is to eliminate ammonia via assimilation to biomass rather than oxidation to nitrate.

Back to reading...

[rsucre]

Originally Posted by bertoni

I certainly agree that carbon dosing sometimes seems to fail. We could test the hypothesis about the direct consumption of ammonia by putting a bit of rock in a container with a skimmer, etc, and feeding it some nitrate. There's going to be little ammonia created if there's no food added. If the nitrate disappears, that could be due to denitrification or more direct consumption of nitrate, and less likely to be ammonia uptake. I'd need to think about this for a bit, though.

My experience with my other tank, a 10 gallon AIO, has been excellent, both with NOPOX and more recently (perhaps 3 months now) with vinegar. NO3 undetectable by Red Sea Pro Kit and PO4 very low at 0.02ppm with Hanna ULR Phosphorus checker.

No scientific or chemistry background, no formal methodology followed here, but from my own experience and observation, it seems to me that vodka, NOPOX and vinegar carbon dosing work.

It is with my 25 gallon (20 dp + 5 sump) that I'm having this challenge of getting the NO3 below 5ppm after switching from "DIY" NOPOX (vodka + vinegar + RO mix). PO4 is OK at 0.02ppm. Perhaps Randy can give some feedback about it?

Would be nice getting to the bottom of this "inconsistency" in the vinegar dosing table when comparing small vs. large volumes.

[Dan_P]

Originally Posted by rsucre

It is with my 25 gallon (20 dp + 5 sump) that I'm having this challenge of getting the NO3 below 5ppm after switching from "DIY" NOPOX (vodka + vinegar + RO mix)

Are you saying that you were below 5 ppm with DIY NOPOX?

[rsucre]

Originally Posted by Dan_P

Are you saying that you were below 5 ppm with DIY NOPOX?

Yes... In both of my tanks (10 gallon and 25 gallon) I got to almost 0ppm on both NO3 and PO4, measured with good kits (Red Sea Pro and Hanna colorimeter respectively) with DIY NOPOX. Then I switched to Vinegar dosing because I wanted to automate it with dosing pump, obviously making the adjustment, taking into account that the vodka part of my DIY NOPOX is 7-8 times stronger than vinegar.

Since then, the 10 gallon tank stayed stable with very low NO3 and PO4 (undetectable NO3 and 0.02 or close to that PO4), but the 25 gallon has NO3 raised to 5-6ppm and PO4 at 0.02 - 0.03ppm (sometimes may get to 0.05ppm), which seems reasonable.

The 10 gallon tank has some algae green and brown algae growing on the glass and back. So, definitely the values are higher than tests show. But it is doing great.

The 25 gallon tank has less green algae than the 10 gallon, but has a lot of cyano growing on the sand bed. It has a very active urchin, so it may be helping with the green algae.

That's a summary of the situation.

[Dan_P]

Originally Posted by rsucre

Would be nice getting to the bottom of this "inconsistency" in the vinegar dosing table when comparing small vs. large volumes.

The German article, where I think it all started, suggested an increase after week 2 of 0.5 mL for systems <300 L and 1mL for systems >300 L. I think neither the authors nor audience understood or caught the fact that the suggested carbon addition scheme added less carbon per gallon as the system became larger.

[Dan_P]

Originally Posted by bertoni

I certainly agree that carbon dosing sometimes seems to fail. We could test the hypothesis about the direct consumption of ammonia by putting a bit of rock in a container with a skimmer, etc, and feeding it some nitrate. There's going to be little ammonia created if there's no food added. If the nitrate disappears, that could be due to denitrification or more direct consumption of nitrate, and less likely to be ammonia uptake. I'd need to think about this for a bit, though.

Yeah, tough to unravel. I think the question is whether carbon dosing gooses nitrate consumption. Toonen’s experiment on different substrates might provide help with an experimental design.

If nitrate consumption is not goosed, then carbon dosing might be changing how ammonia is consumed and the system just slowly consumes nitrate.

[bertoni]

Originally Posted by Dan_P

If nitrate consumption is not goosed, then carbon dosing might be changing how ammonia is consumed and the system just slowly consumes nitrate.

That certainly seems possible. I'm somewhat skeptical about the likelihood because nature generally is fairly good at consuming nutrients. It's hard to say, though.

[taricha]

Originally Posted by Dan_P;2533050S

The bigger the system you have, the greater the probability you underdosed, though I am still not clear what the science is that supports the dosing rate. I believe the notion of carbon dosing came from commericial aquaculture. One approach called the Belize method selects a carbohydrate addition rate that corresponds to the amount of protein in the feed, i.e., the nitrogen input. The logic of the approach is to eliminate ammonia via assimilation to biomass rather than oxidation to nitrate.

Back to reading...

If one were to refigure a dosing formula for large tanks, would it make more sense to scale it to volume, current tested parameters of N&P, or to food inputs - like scrubbers do with the screen area proportional to #of cubes fed daily?

[Dan_P]

Originally Posted by taricha

If one were to refigure a dosing formula for large tanks, would it make more sense to scale it to volume, current tested parameters of N&P, or to food inputs - like scrubbers do with the screen area proportional to #of cubes fed daily?

The initial dosing, i.e., for the first week, is scaled by the volume of the system, then for all system sizes the dose increases are a constant amount. It would make more sense to base the increased dose on system size. The increase for a 50 gallon would be twice that for a 25 gallon system, 4 times for a 100 gallon system. This assumes the week 2 increment for the 25 gallon system is “correct”.

I believe that we do not know the connection between the ppm of acetate and ppm of nitrate in our systems or for that matter whether there is a connection. And that is why most aquarists start with a low ppm of acetate and slowly increase it to see what happens.

If carbon dosing works like it does in shrimp farms, the extra carbon is used to shunt ammonia into bacterial biomass away from oxidation to nitrate. For aquariums, the existing nitrate might be consumed through denitrification, by algae or coral and the carbon dosing is not involved at all, though I have read suggestions that the dosed carbon feeds denitrifying bacteria too.

I started dosing to achieve a daily 1 ppm level of acetate. I will monitor things (pore water NH3 & PO4, tank alkalinity use rate, chlorine demand-a measure of organics, skimmate production, cyanobacteria, algae and the fish) for a couple weeks to see what is changing before deciding to increase dose, maintain it at 1ppm or abort the experiment.

[bertoni]

The results should be interesting.

[rsucre]

I wonder how the vinegar table in question compares against the NOPOX instructions, adapted to only vinegar. I don’t have NOPOX instructions on hand. Also, the method (ramp up, etc. ) recommended by Res Sea for small vs. large volume tanks.

The formula that I used for DIY NOPOX was:

Vodka 80 proof (Absolut): 37.5 ml
Vinegar (5% acetic acid): 50 ml
RO water: 12.5 ml
Total: 100 ml

[Dan_P]

Originally Posted by rsucre

I wonder how the vinegar table in question compares against the NOPOX instructions, adapted to only vinegar. I don’t have NOPOX instructions on hand. Also, the method (ramp up, etc. ) recommended by Res Sea for small vs. large volume tanks.

The formula that I used for DIY NOPOX was:

Vodka 80 proof (Absolut): 37.5 ml
Vinegar (5% acetic acid): 50 ml
RO water: 12.5 ml
Total: 100 ml

The Red Sea dosing is simple, no ramp up. 3 mL per day per 25 gallons for 1-10 ppm nitrate, 2 mL for 0.25-1 and maintainence dose of 1 mL. 3 mL of DIY solution would be about 1.2 mL vodka and 1.5 mL vinegar. So, roughly 10 mL of vinegar (if 1 mL vodka = 8 mL vinegar) per 25 gallons per day if the math I did in my head is correct.

[rsucre]

Originally Posted by Dan_P

The Red Sea dosing is simple, no ramp up. 3 mL per day per 25 gallons for 1-10 ppm nitrate, 2 mL for 0.25-1 and maintainence dose of 1 mL. 3 mL of DIY solution would be about 1.2 mL vodka and 1.5 mL vinegar. So, roughly 10 mL of vinegar (if 1 mL vodka = 8 mL vinegar) per 25 gallons per day if the math I did in my head is correct.

The 3ml of NOPOX per day per 25 gallons of system water would equate to around 11ml of vinegar, according to my calculations.

[rsucre]

It seems that raising the daily dose is starting to show results. Today, NO3 is down at 1.5 ppm and PO4 is 0ppm. I'm happy to see the NO3 down, but a little worried about PO4 at zero.

It is probably premature to say, but it seems from observation that the coral have been happier for the last few days.

I will keep running the vinegar at 27ml (current dose) for a few more days and keep monitoring. Perhaps I should step back to 24ml if NO3 falls below 1.5ppm and PO4 remains at zero OR I see any adverse effect on coral.

Or maybe this is the ideal dose and I should just start to dose Red Sea Reef Energy (aminos) and/or increase the Reef Roids (which I reduced recently to 2 x week).

Any thoughts?

p.s. Cyano still growing on sand bed, but perhaps a little less.

[bertoni]

I'd just keep watching the corals. Adding a bit more food might be fine at some point, but I'd see how the current dose shapes up over a longer period of time, personally. I've never needed to dose carbon, though.

[rsucre]

Originally Posted by bertoni

I've never needed to dose carbon, though.

Interesting. I assumed that you dosed vodka, vinegar, NOPOX or some sort of carbon dosing to your tanks.

[bertoni]

Removing a crushed coral substrate ended all my tanks' dissolved nutrient problems.

[rsucre]

Originally Posted by bertoni

Removing a crushed coral substrate ended all my tanks' dissolved nutrient problems.

Sorry to hear that. So you currently have no tanks up and running? Plan to rebuild them?

[Dan_P]

Originally Posted by rsucre

It seems that raising the daily dose is starting to show results. Today, NO3 is down at 1.5 ppm and PO4 is 0ppm. I'm happy to see the NO3 down, but a little worried about PO4 at zero.

It is probably premature to say, but it seems from observation that the coral have been happier for the last few days.

I will keep running the vinegar at 27ml (current dose) for a few more days and keep monitoring. Perhaps I should step back to 24ml if NO3 falls below 1.5ppm and PO4 remains at zero OR I see any adverse effect on coral.

Or maybe this is the ideal dose and I should just start to dose Red Sea Reef Energy (aminos) and/or increase the Reef Roids (which I reduced recently to 2 x week).

Any thoughts?

p.s. Cyano still growing on sand bed, but perhaps a little less.

I am interested in the cyano outcome.

I haven’t made it past 2009 in my reseaerch. Up to that time, the advice was to stop increasing or even halve the dose when you met your nitrate/phosphate goal.

If you have time on your hand, test the pore water of the system with 0 ppm phosphate. You might find some lurking in the sand. I am surveying the pore water in my aquarium at several locations during carbon dosing. Ammonia and phosphate are usually there, but will dosing decrease it.

[rsucre]

Originally Posted by Dan_P

I am interested in the cyano outcome.



I haven’t made it past 2009 in my reseaerch. Up to that time, the advice was to stop increasing or even halve the dose when you met your nitrate/phosphate goal.



If you have time on your hand, test the pore water of the system with 0 ppm phosphate. You might find some lurking in the sand. I am surveying the pore water in my aquarium at several locations during carbon dosing. Ammonia and phosphate are usually there, but will dosing decrease it.

What is pore water? Sorry, English is not my native language.


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[bertoni]

Originally Posted by rsucre

Sorry to hear that. So you currently have no tanks up and running? Plan to rebuild them?

I keep thinking about it. I had to tear them down when I was commuting to China regularly for a job. I haven't had to do that for a while.

[rsucre]

Originally Posted by bertoni

I keep thinking about it. I had to tear them down when I was commuting to China regularly for a job. I haven't had to do that for a while.

Jonathan, build a nano and let’s keep track of your carbon dosing since the beginning


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[Dan_P]

Originally Posted by rsucre

What is pore water? Sorry, English is not my native language.


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Sorry. Pore water refers to the water in the substrate. The water that occupies the space between sand grains.

[rsucre]

Originally Posted by Dan_P

Sorry. Pore water refers to the water in the substrate. The water that occupies the space between sand grains.

I can take a measure tomorrow, but I think that it may not be as accurate. The water from the bottom could have more particulate matter and I test PO4 using a Hanna colorimeter. Do you want me to take the water sample near the bottom of the DP or the sump refugium section? Can it be a couple mm above the sandbed?

[Dan_P]

Originally Posted by rsucre

I can take a measure tomorrow, but I think that it may not be as accurate. The water from the bottom could have more particulate matter and I test PO4 using a Hanna colorimeter. Do you want me to take the water sample near the bottom of the DP or the sump refugium section? Can it be a couple mm above the sandbed?

When I take a sample it’s 2-3 cm deep. To avoid particulates, I draw the sample through a bit of filter floss that covers the tip of the syringe, though if that is not possible you could pass the sample through the filter floss after collecting it or just let it settle out and test the clearer liquid. It is not very precise but we are only trying to distinguish between 0.1 ppm and 1 ppm PO4.

If you are using the Hanna checker, the cloudiness will be taken into account when you use the sample as a blank in the “C1” step. You may find that the Hanna ULR reading exceeds 200. If you are interested in a number, the sample will have to be diluted with RO/DI water before testing it again. I can help with that if you wish.