Should We Be Carbon dosing?

[Reefology1]

I've been in the reefing hobby for decades and I've never had a better looking or thriving aquarium than the early years. I attribute that to knowing very little at the time (the less you know, the less you change), starting out with live rock, 3" aragonite sand bed, a crappy skimmer that basically didn't pull out much of anything, and very few fish.

Fast forward to my current system that’s 5 years old. It started out with dry rock, a sprinkling of aragonite gravel (I don't like the look of bare bottom), an ATS and an oversized skimmer. I had issues initially with "the ugly stage" seemingly lasting forever. The system at the time was running sterile and I had a heck of a time trying to get nutrients up. So I added a lot more fish, turned my skimmer and ATS lights off for half the day and things turned for the better.

A few years later, the nutrients climbed to where my nitrates where running around 30ppm and phosphates around 0.4ppm. I increased run time on my skimmer and ATS to 18hrs a day and started carbon dosing. I used vinegar and gfo to slowly get nutrients back in check (no3 <2 and po4 <0.1), and today use those same methods to keep them there.

This brings me to the reason for this thread: should I continue to carbon dose?

I’ve read on more than one occasion, in this forum, that Randy Holmes-Farley would dose vinegar (even if dosing nitrates was required) because of the increased bacteria as a food source to filter feeders and other organisms. This is one of the main reasons I continue to dose vinegar, even though my nutrients are in check.

Recently I’ve been toying with the idea of adding amino acids to my vinegar dosing container to reduce po4 without the use of gfo. In doing so, I started to wonder, should I still be carbon dosing? And if so, what should i dose (amino and vinegar)? How does carbon dosing affect the macros in my ATS? How does my ATS affect carbon dosing?

Hoping those for and against carbon dosing can chime in to share your views to help me answer some of the questions above.

Thank You

 

[X-37B]

I carbon dose but only to feed the macro amd corals. I dose 4ml into my 30g refugium daily. I use EZ carbon which is a blend of vinegar, sugar, and iron. It does not do anything noticable to reduce no3 or po4 at that low amount.

 

[PatW]

If it isn’t broken don’t fix it. Reef aquariums are complex systems. I do nor think we understand them that well. What works in my tank might not work in yours, Once you get things working just steady as you go.

 

[Reefology1]

Reef aquariums are complex systems. I do nor think we understand them that well.

Thank you for the response. But that’s precisely why I’m asking.

 

[Dan_P]

I've been in the reefing hobby for decades and I've never had a better looking or thriving aquarium than the early years. I attribute that to knowing very little at the time (the less you know, the less you change), starting out with live rock, 3" aragonite sand bed, a crappy skimmer that basically didn't pull out much of anything, and very few fish.

Fast forward to my current system that’s 5 years old. It started out with dry rock, a sprinkling of aragonite gravel (I don't like the look of bare bottom), an ATS and an oversized skimmer. I had issues initially with "the ugly stage" seemingly lasting forever. The system at the time was running sterile and I had a heck of a time trying to get nutrients up. So I added a lot more fish, turned my skimmer and ATS lights off for half the day and things turned for the better.

A few years later, the nutrients climbed to where my nitrates where running around 30ppm and phosphates around 0.4ppm. I increased run time on my skimmer and ATS to 18hrs a day and started carbon dosing. I used vinegar and gfo to slowly get nutrients back in check (no3 <2 and po4 <0.1), and today use those same methods to keep them there.

This brings me to the reason for this thread: should I continue to carbon dose?

I’ve read on more than one occasion, in this forum, that Randy Holmes-Farley would dose vinegar (even if dosing nitrates was required) because of the increased bacteria as a food source to filter feeders and other organisms. This is one of the main reasons I continue to dose vinegar, even though my nutrients are in check.

Recently I’ve been toying with the idea of adding amino acids to my vinegar dosing container to reduce po4 without the use of gfo. In doing so, I started to wonder, should I still be carbon dosing? And if so, what should i dose (amino and vinegar)? How does carbon dosing affect the macros in my ATS? How does my ATS affect carbon dosing?

Hoping those for and against carbon dosing can chime in to share your views to help me answer some of the questions above.

Thank You

Do I conclude correctly that the ATS was inadequate in exporting nitrogen and vinegar dosing was started to increase nitrogen export? And now both ATS and vinegar dosing are being used to maintain the nitrate level where you want?

 

[Dkmoo]

so.. basically, Carbon feeds bacteria. Bacteria comes in all size and shapes - some are good, some are bad. when you dose carbon you basically are increasing DOC in the water. DOC doesn't differentiate if it feeds the good vs the bad bacteria.

there's actual new research that looked into algae growth that seem to show that its not "excess nutrient" that causes algae, but rather this cycle of algae ->releasing DOC/sugars via photosynthesys ->bad bacteria on coral surface eat the DOC -> localized O2 level drop due to bacteria ->coral suffocate and die - >local rotting coral flesh fuel more bacteria.

maybe i'm butchering the explanation but @Timfish is the first one that showed this to me with his links to direct research source. I have since stopped dosing carbon. I dose amino instead.

 

[Mywifeisgunnakillme]

No, it creates a mess and can grow bacteria that is harmful.

 

[Reefology1]

maybe i'm butchering the explanation but @Timfish is the first one that showed this to me with his links to direct research source. I have since stopped dosing carbon. I dose amino instead.

I think you may have butchered it but I’m sure I would have also.

when you say you’re not dosing carbon, Aren’t amino acid a carbon source?!

 

[Tbg299]

I've never carbon dosed and honestly I don't see the need to if you are feeding amino acid rich foods like Oyster Feast, etc.

 

[Tbg299]

I think you may have butchered it but I’m sure I would have also.

when you say you’re not dosing carbon, Aren’t amino acid a carbon source?!

Yes they are. They contain a carboxyl group.

 

[Reefology1]

Do I conclude correctly that the ATS was inadequate in exporting nitrogen and vinegar dosing was started to increase nitrogen export? And now both ATS and vinegar dosing are being used to maintain the nitrate level where you want?

Well, I got more fish and feed more heavily, run my ATS lights at 50% intensity and not as long as I could...so not that simple, but yes, you can say that to a degree.

 

[Cory]

Bacteria are eaten by corals via ones that get trapped in their slime or the ones that grow in their slime. Dosing carbon sources will increase bacteria everywhere that the coral can eat. The problem is when you dose too much or when there isnt any po4 or no3 for the bacteria to consume.

 

[X-37B]

Bacteria are eaten by corals via ones that get trapped in their slime or the ones that grow in their slime. Dosing carbon sources will increase bacteria everywhere that the coral can eat. The problem is when you dose too much or when there isnt any po4 or no3 for the bacteria to consume.

It is a balance for sure.
I keep po4 @ <.1 and no3@ <5.
This allows me to carbon dose small amounts that I believe are benificial to the corals and macro algae in my fuge.

 

[Dan_P]

Well, I got more fish and feed more heavily, run my ATS lights at 50% intensity and not as long as I could...so not that simple, but yes, you can say that to a degree.

OK, just needed clarification because it seems like your system is under control and doing fine (I assume) and you are thinking of further optimizing nitrogen export. Your questions are excellent.

My first thought is that you have no reason to change what you are doing. You nailed it. My second thought is that you could slowly wean your system of vinegar by ramping up the ATS activity. Is your ATS up to being the sole nitrogen exporter?

Another thought is that weaning PO4 export by GFO with dosing is moving to a less reliable/less controllable method.

And finally, dosing amino acids might stimulate cyanobacteria growth. A very active ATS might be enough to remove PO4.

Oops, one more thought. Exporting nitrogen by growing bacteria and algae can consume trace elements. Watch for trace element depletion. For my system, trace element depletion (Which ones? I don’t know) came with little or no coralline algae growth and cessation of Ulva macro algae growth.

 

[Dkmoo]

I think you may have butchered it but I’m sure I would have also.

when you say you’re not dosing carbon, Aren’t amino acid a carbon source?!

Right let me clarify. My thought process is that when people say "carbon dosing" they use it as a form of no3/po4 export by promoting bacteria growth that would otherwise by "carbon limited" (something about Redfield ratio). Since now we have much more effective other methods of no3/po4 export, it seems carbon dosing is not worth the risk with the good bacteria/bad bacteria issue. Amino dosing to me is worth the risk of adding carbon bc its purpose is to introduce direct coral nutrition, esp for things thats hard for corals to come by naturally via photosynthesis or via capturing in an artificql reef tank setting.

 

[Reefology1]

OK, just needed clarification because it seems like your system is under control and doing fine (I assume) and you are thinking of further optimizing nitrogen export. Your questions are excellent.

My first thought is that you have no reason to change what you are doing. You nailed it. My second thought is that you could slowly wean your system of vinegar by ramping up the ATS activity. Is your ATS up to being the sole nitrogen exporter?

Another thought is that weaning PO4 export by GFO with dosing is moving to a less reliable/less controllable method.

And finally, dosing amino acids might stimulate cyanobacteria growth. A very active ATS might be enough to remove PO4.

Oops, one more thought. Exporting nitrogen by growing bacteria and algae can consume trace elements. Watch for trace element depletion. For my system, trace element depletion (Which ones? I don’t know) came with little or no coralline algae growth and cessation of Ulva macro algae

I think you nailed it! @Dan_P that sums up my situation. However, I’m no farther ahead and back where I started.

- Should I leave well enough alone?
- Should I add aminos to my carbon dosing container (not worried about cyano)?
- up my ATS?
- slow down on feeding?
- ...
And before you ponder anything above, would you happen to know why reef tanks tend to be carbon deficient? I have never known why!

 

[Reefology1]

Bacteria are eaten by corals via ones that get trapped in their slime or the ones that grow in their slime. Dosing carbon sources will increase bacteria everywhere that the coral can eat. The problem is when you dose too much or when there isnt any po4 or no3 for the bacteria to consume.

So why not just dose less carbon? Or dose more N and P? Which one do you choose? Does it even matter?

 

[Reefology1]

Right let me clarify. My thought process is that when people say "carbon dosing" they use it as a form of no3/po4 export by promoting bacteria growth that would otherwise by "carbon limited" (something about Redfield ratio). Since now we have much more effective other methods of no3/po4 export, it seems carbon dosing is not worth the risk with the good bacteria/bad bacteria issue. Amino dosing to me is worth the risk of adding carbon bc its purpose is to introduce direct coral nutrition, esp for things thats hard for corals to come by naturally via photosynthesis or via capturing in an artificql reef tank setting.

I think I know what you’re getting at. But that doesn’t change the fact that you’re still carbon dosing. And what make you think that “bad bacteria” isnt consuming carbon from amino acids?

 

[vetteguy53081]

Dont do it unless absolutely needed. Not saying its bad as it The first advantage to carbon dosing it allows you to feed much more heavily. While some fish and invertebrates would fare better if fed more frequently or in higher quantities, it can impact the filtering capacity of the system. If the filtering capacity of your system is exceeded, heavy feeding can cause a buildup of nutrients that will lead to poor water quality and increased maintenance.

 

[Dan_P]

I think you nailed it! @Dan_P that sums up my situation. However, I’m no farther ahead and back where I started.

- Should I leave well enough alone?
- Should I add aminos to my carbon dosing container?
- up my ATS?
- slow down on feeding?
- ...
And before you ponder anything above, would you happen to know why reef tanks tend to be carbon deficient? I have never known why!

Carbon deficiency comes about because food or a living organisms is consumed for two purposes: to generate energy and to build biomass. Making energy uses organic carbon but not nitrogen or phosphorous. Building biomass uses carbon, nitrogen and phosphorous.

A large portion of what an organism consumes goes to making energy, that is, the carbon is primarily used up. That is why nitrogen (e.g., nitrate) and phosphorous (mostly phosphate) tend to accumulate in the aquarium. The other waste product CO2 can escape.
If you keep an inventory of the food elements imported into the aquarium that are used versus left behind, N and P are alsways larger than C. When we carbon dose, the balance in the food inventory shifts.

Carbon dosing supplies bacteria the needed energy for growth and building biomass, resulting in the N and P in the aquarium being sopped up. This is regularly done in fish farms, though they use other carbon sources. In principle, fish food could be mixed with extra organic carbon to keep the carbon inventory high enough to consume all the nitrogen, though maybe not the phosphorous.

Make sense?