Designing a carbon dosing experiment

[rishma]

@Dan_P and others,
I am thinking of running a carbon dosing experiment. Dan did a lot of work in this space so I am not aiming to duplicate it but would appreciate some tips and feedback.

My goal is to determine how much nitrate to add to vinegar so that nitrate in the tank is not reduced. Why would I do this? Because if nitrate is stable the solution would still reduce phosphate. That seems like a handy thing to do.

I would use sodium nitrate because I think ammonium bicarbonate would be harder to apply in a tank due to rapid uptake by corals and algae. Nitrate would be a bit more stable.

So here is what I’d do…

1 L samples of tank water. I’d aerate them 24-48 hours and let them stabilize because the tank is carbon dosed and I assume some bacterial action would continue after I pulled the water.

I’d measure the nitrate and phosphate in the samples and dose them to a target value. Like 10ppm nitrate and 0.2ppm phosphate. Test samples after dosing to confirm. I’d leave a sample un-dosed to use às a control.

I’d then dose a fixed amount of vinegar (amount TBD, feedback appreciated) and monitor nitrate and phosphate levels for a week (will need to check time based on Dan’s experiments)

Assuming I get some meaningful data, I’d then repeat the experiment but also dose some nitrate with the vinegar to offset the consumption observed the first time. If this works (which it might not!) nitrate would be about the same at the end and phosphate would be lower than the previous tests.

There may be a shortcut. I seem to recall @Dan_P telling us he saw 15 or 20 to 1 N:P consumption. I need to find that thread.

Thoughts?

 

[Randy Holmes-Farley]

Seems like a very worthy goal, though the result may be a bit system dependent since if there is denitrification taking place (using more N than aerobic consumption of the organic alone would) that amount may be variable between systems.

Another possibility is to add both N and P with the organic to give a way to create bacteria coral food in tank without altering nutrients.,

Finally, a smaller amount of N and P with the organic could allow nutrient reduction with less risk of bottoming out on any given day, like the TM products suggest.

 

[rishma]

Seems like a very worthy goal, though the result may be a bit system dependent since if there is denitrification taking place (using more N than aerobic consumption of the organic alone would) that amount may be variable between systems.

Another possibility is to add both N and P with the organic to give a way to create bacteria coral food in tank without altering nutrients.,

Finally, a smaller amount of N and P with the organic could allow nutrient reduction with less risk of bottoming out on any given day, like the TM products suggest.

All good ideas! System dependent seems likely. This could become a new hobby

 

[Dan_P]

@Dan_P and others,
I am thinking of running a carbon dosing experiment. Dan did a lot of work in this space so I am not aiming to duplicate it but would appreciate some tips and feedback.

My goal is to determine how much nitrate to add to vinegar so that nitrate in the tank is not reduced. Why would I do this? Because if nitrate is stable the solution would still reduce phosphate. That seems like a handy thing to do.

I would use sodium nitrate because I think ammonium bicarbonate would be harder to apply in a tank due to rapid uptake by corals and algae. Nitrate would be a bit more stable.

So here is what I’d do…

1 L samples of tank water. I’d aerate them 24-48 hours and let them stabilize because the tank is carbon dosed and I assume some bacterial action would continue after I pulled the water.

I’d measure the nitrate and phosphate in the samples and dose them to a target value. Like 10ppm nitrate and 0.2ppm phosphate. Test samples after dosing to confirm. I’d leave a sample un-dosed to use às a control.

I’d then dose a fixed amount of vinegar (amount TBD, feedback appreciated) and monitor nitrate and phosphate levels for a week (will need to check time based on Dan’s experiments)

Assuming I get some meaningful data, I’d then repeat the experiment but also dose some nitrate with the vinegar to offset the consumption observed the first time. If this works (which it might not!) nitrate would be about the same at the end and phosphate would be lower than the previous tests.

There may be a shortcut. I seem to recall @Dan_P telling us he saw 15 or 20 to 1 N:P consumption. I need to find that thread.

Thoughts?

Recap: Your goal is to dose a mixture of vinegar and nitrate to stimulate bacteria growth to consume phosphate and keep the sysem’s nitrate untouched.

You probably could use ammonium carbonate because the bacteria are going to dominate it’s consumption because of the presence of vinegar AND ammonia, not nitrate, is going to be the bacteria’s first choice of inorganic nitrogen. So, don’t give up trying to make ammonium carbonate work in place of sodium nitrate.

In a perfect world, 7 molecules of acetic acid are consumed for every nitrate molecule. 1 mL of vinegar in a gallon of water is about 13 ppm acetic acid. Divide this by 60 to get the millimolar concentration. Divide ppm of nitrate by 62 to get the millimolar concentration. Or notice that nitrate and acetic acid have similar molecular weights and just use ppm, i.e., it takes 7 ppm of vinegar to nail 1 ppm nitrate.

On a good day in that perfect world, 1 ppm of phosphate is consumed for every 10 ppm nitrate consumed. In real life, phosphate consumption might be more variable the you like.

The aeration is a good idea, but you don’t need to wait to use the solution. The bacteria will be ready to metabolize right away, though the first dose takes 12-24 hours to work compared to subsequent doses which get used up in 2-4 hours. After the third dose, bacteria growth can become erratic as.observed by the slow down in phosphate consumption or even the increase in phosphate. If you use ammonium carbonate, bacteria might behave better. I haven’t used ammonia much.

 

[rishma]

Recap: Your goal is to dose a mixture of vinegar and nitrate to stimulate bacteria growth to consume phosphate and keep the sysem’s nitrate untouched.

You probably could use ammonium carbonate because the bacteria are going to dominate it’s consumption because of the presence of vinegar AND ammonia, not nitrate, is going to be the bacteria’s first choice of inorganic nitrogen. So, don’t give up trying to make ammonium carbonate work in place of sodium nitrate.

In a perfect world, 7 molecules of acetic acid are consumed for every nitrate molecule. 1 mL of vinegar in a gallon of water is about 13 ppm acetic acid. Divide this by 60 to get the millimolar concentration. Divide ppm of nitrate by 62 to get the millimolar concentration. Or notice that nitrate and acetic acid have similar molecular weights and just use ppm, i.e., it takes 7 ppm of vinegar to nail 1 ppm nitrate.

On a good day in that perfect world, 1 ppm of phosphate is consumed for every 10 ppm nitrate consumed. In real life, phosphate consumption might be more variable the you like.

The aeration is a good idea, but you don’t need to wait to use the solution. The bacteria will be ready to metabolize right away, though the first dose takes 12-24 hours to work compared to subsequent doses which get used up in 2-4 hours. After the third dose, bacteria growth can become erratic as.observed by the slow down in phosphate consumption or even the increase in phosphate. If you use ammonium carbonate, bacteria might behave better. I haven’t used ammonia much.

Thanks! You summarized correctly what the initial goal would be. Alternatively I might then try to balance both nitrate and phosphate as Randy suggested. Same approach though.

I’m concerned that if I use ammonia it might work well in the experiment but when I transition to the tank it will be consumed by algae and coral and not keep nitrate unchanged.

You think bacteria is so fast at using ammonia it won’t matter?

 

[Subsea]

Bacteria, coral zooanthellia and algae prefer ammonia to nitrate.

 

[rishma]

Bacteria, coral zooanthellia and algae prefer ammonia to nitrate.

Yep!

 

[Subsea]

@Dan_P and others,
I am thinking of running a carbon dosing experiment. Dan did a lot of work in this space so I am not aiming to duplicate it but would appreciate some tips and feedback.

My goal is to determine how much nitrate to add to vinegar so that nitrate in the tank is not reduced. Why would I do this? Because if nitrate is stable the solution would still reduce phosphate. That seems like a handy thing to do.

I would use sodium nitrate because I think ammonium bicarbonate would be harder to apply in a tank due to rapid uptake by corals and algae. Nitrate would be a bit more stable.

So here is what I’d do…

1 L samples of tank water. I’d aerate them 24-48 hours and let them stabilize because the tank is carbon dosed and I assume some bacterial action would continue after I pulled the water.

I’d measure the nitrate and phosphate in the samples and dose them to a target value. Like 10ppm nitrate and 0.2ppm phosphate. Test samples after dosing to confirm. I’d leave a sample un-dosed to use às a control.

I’d then dose a fixed amount of vinegar (amount TBD, feedback appreciated) and monitor nitrate and phosphate levels for a week (will need to check time based on Dan’s experiments)

Assuming I get some meaningful data, I’d then repeat the experiment but also dose some nitrate with the vinegar to offset the consumption observed the first time. If this works (which it might not!) nitrate would be about the same at the end and phosphate would be lower than the previous tests.

There may be a shortcut. I seem to recall @Dan_P telling us he saw 15 or 20 to 1 N:P consumption. I need to find that thread.

Thoughts?

“There may be a shortcut. I seem to recall @Dan_P telling us he saw 15 or 20 to 1 N:P consumption. I need to find that thread.“

Phytoplankton N:P is 16:1
Gracilaria Parvispora N:P is 30:1

I am going to link you to carbon dosing peer reviewed article by Ken Feldman & Sanja both pHD micro biologist and both reef hobbiest. My bad, I can’t find it.

Bacteria Families Removed By The Skimmer

Extremely interesting read. I need to go back and start over, as I am sure I have missed several facets. It has been awhile. We are just starting to have some fun

www.reef2reef.com

 

[Subsea]

@Dan_P and others,
I am thinking of running a carbon dosing experiment. Dan did a lot of work in this space so I am not aiming to duplicate it but would appreciate some tips and feedback.

My goal is to determine how much nitrate to add to vinegar so that nitrate in the tank is not reduced. Why would I do this? Because if nitrate is stable the solution would still reduce phosphate. That seems like a handy thing to do.

I would use sodium nitrate because I think ammonium bicarbonate would be harder to apply in a tank due to rapid uptake by corals and algae. Nitrate would be a bit more stable.

So here is what I’d do…

1 L samples of tank water. I’d aerate them 24-48 hours and let them stabilize because the tank is carbon dosed and I assume some bacterial action would continue after I pulled the water.

I’d measure the nitrate and phosphate in the samples and dose them to a target value. Like 10ppm nitrate and 0.2ppm phosphate. Test samples after dosing to confirm. I’d leave a sample un-dosed to use às a control.

I’d then dose a fixed amount of vinegar (amount TBD, feedback appreciated) and monitor nitrate and phosphate levels for a week (will need to check time based on Dan’s experiments)

Assuming I get some meaningful data, I’d then repeat the experiment but also dose some nitrate with the vinegar to offset the consumption observed the first time. If this works (which it might not!) nitrate would be about the same at the end and phosphate would be lower than the previous tests.

There may be a shortcut. I seem to recall @Dan_P telling us he saw 15 or 20 to 1 N:P consumption. I need to find that thread.

Thoughts?

“My goal is to determine how much nitrate to add to vinegar so that nitrate in the tank is not reduced. Why would I do this? Because if nitrate is stable the solution would still reduce phosphate. That seems like a handy thing to do.“

Let’s park here:
You will be measuring inorganic nutrients.

Cynobacteria within coral biomass convert nitrogen gas molecules that are dissolved in water (Dynamic Equilibrium) to ammonia thru a process called “nitrogen fixation”. Now you have an organic component to your experiment.

As a municipal waste water superintendent of a Shrivier activated sludge plant with a Class 5 certification, I am certified to train people to stir sewage.

@rishma
You can not assume that N:P ratio is constant.
N:P ratio WILL NOT BE CONSTANT.

Know this. We stressed the sewage system with loss of oxygen then reestablished air. The total inorganic phosphate (ortho phosphate) was decreased as bacteria assimilated nutrients to repair their cell membranes & biomass. When bacteria died after reproduction, the accumulated sluge was pumped to drying beds where a process to significantly reduce pathogens which depended on the “beneficial reuse” of the end user. In our application, we spread dried bacteria sludge on grass land that had cattle grazing 30 days after application.

 

[Dan_P]

Thanks! You summarized correctly what the initial goal would be. Alternatively I might then try to balance both nitrate and phosphate as Randy suggested. Same approach though.

I’m concerned that if I use ammonia it might work well in the experiment but when I transition to the tank it will be consumed by algae and coral and not keep nitrate unchanged.

You think bacteria is so fast at using ammonia it won’t matter?

I think it is worth trying. I can’t say for sure if bacteria are clear winners.

 

[rishma]

@rishma
You can not assume that N:P ratio is constant.
N:P ratio WILL NOT BE CONSTANT.

.

It makes sense under some significantly different conditions that the N:P will vary. Are you saying that you think it won’t be repeatable in the experiment and or it won’t be applicable to the aquarium?

 

[Subsea]

It makes sense under some significantly different conditions that the N:P will vary. Are you saying that you think it won’t be repeatable in the experiment and or it won’t be applicable to the aquarium?

I am saying “nothing happens in a vacuum”. Each change affects both organic & inorganic world. Meaning, it’s difficult to quantify individual contributions.

Consider this: I am a Marine Engineer and my wife is a Board Certified Social Worker or in Texas a Licensed Professional Counsel.

I consider my science degree as hard science and hers is soft science. So, to evaluate why did an individual act a certain way and the two inputs are: DNA and environmental. I say
Go figure.

 

[rishma]

I am saying “nothing happens in a vacuum”. Each change affects both organic & inorganic world. Meaning, it’s difficult to quantify individual contributions.

Consider this: I am a Marine Engineer and my wife is a Board Certified Social Worker or in Texas a Licensed Professional Counsel.

I consider my science degree as hard science and hers is soft science. So, to evaluate why did an individual act a certain way and the two inputs are: DNA and environmental. I say
Go figure.

Ok. Failure of this endeavor is certainly possible.

 

[Randy Holmes-Farley]

As a municipal waste water superintendent of a Shrivier activated sludge plant with a Class 5 certification, I am certified to train people to stir sewage.

lol

Next time I plan to do that, I know who to ask for details on the optimal way.

 

[Crosbie]

I essentially did this last year for a few months because of out of control phosphates which I struggle to keep under 0.3 running 1kg of gfo for a 250L tank.

I used reef Zlements Nitro 10x and their Carboplus. It absolutely worked, however the biomass got out of control, eventually stalling pumps. At least in my experience with a small tank it wasn't viable without substantially increasing surface area for the bacteria to stop it massing. At its peak it reduced my phosphates down to 0.05 and held steady using zero gfo but alas the biomass killed the experiment. I have a small chamber in my tank stuffed with porous filter media to the brim but it wasn't enough.

I have since removed all the sand in my display to get my phosphate under control, however I now have nitrate climbing which had been stable with my carbon dosing, and increasing it isn't helping. The only reason I bring this up it that the sand in my display, which was only a few cm deep clearly made a big difference in efficacy in my previous experiment.