Sixty’s Understanding of Nutrient Ratios

[Randy Holmes-Farley]

Does this article shed any light (pun intended) on the discussion? I know we're not talking about 'macro algae here' - but the effect of carbon on pest algae: "Growth on organic carbon substrates promotes higher biomass, lipid, and carbohydrate productivity, which further triggers the yield of various biomolecules. Since, the current mass culture practices primarily employ open pond and tubular photobioreactors for phototrophic growth, they become cost intensive and economically non-viable."

Impact of organic carbon acquisition on growth and functional biomolecule production in diatoms - Microbial Cell Factories

Diatoms are unicellular photosynthetic protists which constitute one of the most successful microalgae contributing enormously to global primary productivity and nutrient cycles in marine and freshwater habitats. Though they possess the ability to biosynthesize high value compounds like...

microbialcellfactories.biomedcentral.com

IMO, It supports my claim that organic carbon is not the primary source of carbon for photosyntehsis in green algae and other photosynthetic organisms including most diatoms (the paper below described diatoms as "unique" in this context, although cyanobacteria certainly use organic carbon the same way), and that even diatoms do not use it as a C source for photosynthesis.


"Diatom algae are products of a unique secondary endosymbiotic event between heterotrophic eukaryote and a red alga. This event resulted in amalgamation of genes and resultant metabolic pathways which are unique to diatoms like complete urea cycle, carbon concentrating mechanisms (CCM), four layered chloroplasts, C4 photosynthesis etc."

"In diatoms, majority species prefer photo-autotrophy as the preferred carbon acquisition mode which converts CO2 in the presence of light to reduces carbon."

Can photosynthetic organisms use organics for various purposes if you load up the water with them like the paper is suggesting for industrial reactors? Sure, some can.

 

[MnFish1]

IMO, It supports my claim that organic carbon is not the primary source of carbon for photosyntehsis in green algae and other photosynthetic organisms including most diatoms (the paper below described diatoms as "unique" in this context, although cyanobacteria certainly use organic carbon the same way), and that even diatoms do not use it as a C source for photosynthesis.


"Diatom algae are products of a unique secondary endosymbiotic event between heterotrophic eukaryote and a red alga. This event resulted in amalgamation of genes and resultant metabolic pathways which are unique to diatoms like complete urea cycle, carbon concentrating mechanisms (CCM), four layered chloroplasts, C4 photosynthesis etc."

"In diatoms, majority species prefer photo-autotrophy as the preferred carbon acquisition mode which converts CO2 in the presence of light to reduces carbon."

Can photosynthetic organisms use organics for various purposes if you load up the water with them like the paper is suggesting for industrial reactors? Sure, some can.

Thanks - I wasn't trying to argue with you - I was only trying to clarify for myself. Of course each paper needs to be read in its context - and I only concentrated on the 'abstract conclusions'. I guess the question in my mind is - in certain conditions - could the amount of organic carbon 'influence' the amount of pest algae in the tank? Such as low light conditions.

The conversation brings up a number of questions in my mind - so allow me to pick your brain. For example - would any of this data suggest dosing carbon after lights out - or does it matter? Etc etc. Would the time of 'feeding' the tank influence pest algae. Note I'm not talking about photosynthesis occurring in coral, etc - only things like cyanobacteria, diatoms, etc. Just curious about your thoughts.

My idea would be that organic carbon - (and I think this is your idea as well) - would be more quickly used by bacteria - than having an influence on pest algae. Hey - at least this is more fun discussing than the stock market lol

 

[Randy Holmes-Farley]

Thanks - I wasn't trying to argue with you - I was only trying to clarify for myself. Of course each paper needs to be read in its context - and I only concentrated on the 'abstract conclusions'. I guess the question in my mind is - in certain conditions - could the amount of organic carbon 'influence' the amount of pest algae in the tank? Such as low light conditions.

The conversation brings up a number of questions in my mind - so allow me to pick your brain. For example - would any of this data suggest dosing carbon after lights out - or does it matter? Etc etc. Would the time of 'feeding' the tank influence pest algae. Note I'm not talking about photosynthesis occurring in coral, etc - only things like cyanobacteria, diatoms, etc. Just curious about your thoughts.

My idea would be that organic carbon - (and I think this is your idea as well) - would be more quickly used by bacteria - than having an influence on pest algae. Hey - at least this is more fun discussing than the stock market lol

If you are talking near blackout with dosing of organic carbon, some types of algae may be able to take up some of the organic carbon to help survive.

But algae are called autotrophic organisms for a reason. They are not, like cyanobacteria, partly heterotropic and survive well on organics.

Diverse Applications of Marine Macroalgae

The aim of this paper is to review the multiplicity of the current uses of marine macroalgae. Seaweeds are already used in many products and for different purposes, from food products to medicine. They are a natural resource that can provide a number ...

www.ncbi.nlm.nih.gov

"In this review, the focus is the marine macroalgae or seaweeds, which are multicellular, macroscopic, eukaryotic, and autotrophic organisms."

 

[Randy Holmes-Farley]

This article discusses how some algae can use both CO2 and organics to survive and grow, but that is in a study using 500 ppm glycerol in the water!!!

https://www.sciencedirect.com/science/article/abs/pii/S2211926418300791

"Mixotrophic growth is an ability of microalgae to concurrently assimilate CO2 and organic carbon. In the present study, the use of glycerol to enhance microalgal biomass and lipid productivities was investigated in relation to nitrate availability. Under nitrate sufficient conditions, the biomass productivities of Nannochloropsis salina (CCMP 1776) and a marine Chlorella sp. were 1.7 and 1.9 times higher in mixotrophic culture than under strictly photoautotrophic conditions, respectively. Both algae required light to assimilate glycerol. "


"No significant algae growth was observed under heterotrophic conditions, despite apparent utilisation of both nitrate and glycerol. "

"Experiments were performed with provision of different combinations of light, sodium nitrate, and glycerol. For mixotrophic and heterotrophic experiments, glycerol (Ajax Finechem, ≥99.5%) was included in the growth medium to give an initial concentration of 0.5 g L−1"
.
"Additionally, a carbon mass balance was conducted based on glycerol utilisation and biomass production in N. salina cultures, which revealed a net release of CO2 during mixotrophic growth. "

The last sentence suggests those organisms are using metabolized organics as a source of CO2

 

[MnFish1]

If you are talking near blackout with dosing of organic carbon, some types of algae may be able to take up some of the organic carbon to help survive.

But algae are called autotrophic organisms for a reason. They are not, like cyanobacteria, partly heterotropic and survive well on organics.

Diverse Applications of Marine Macroalgae

The aim of this paper is to review the multiplicity of the current uses of marine macroalgae. Seaweeds are already used in many products and for different purposes, from food products to medicine. They are a natural resource that can provide a number ...

www.ncbi.nlm.nih.gov

"In this review, the focus is the marine macroalgae or seaweeds, which are multicellular, macroscopic, eukaryotic, and autotrophic organisms."

Except I was talking about diatoms and cyanobacteria. I specifically said I'm not talking about macro algae. I was talking about 'pests' in the tank. So - I'm assuming then - that the answer to my question 'Do any of these studies suggest it might be better to feed or dose carbon in darkness - as compared to in light - and same question Re feeding (evening vs morning)? EDIT - would be 'No there would be no (or little) difference?

 

[MnFish1]

@Randy Holmes-Farley PS. thanks for the articles!!

 

[Randy Holmes-Farley]

Except I was talking about diatoms and cyanobacteria. I specifically said I'm not talking about macro algae. I was talking about 'pests' in the tank. So - I'm assuming then - that the answer to my question 'Do any of these studies suggest it might be better to feed or dose carbon in darkness - as compared to in light - and same question Re feeding (evening vs morning)? EDIT - would be 'No there would be no (or little) difference?

I've not heard of anyone getting cyano in the dark part of a reef aquarium, even when organic carbon dosing, and no one is dosing anywhere close to 500 ppm of a standard organic, but it is certainly true and not unexpected that cyano can benefit from organic carbon dosing and might be a pest.

I do not know, nor did I see in my tank, if dosing organics had any effect on diatoms.

 

[sixty_reefer]

Reef tanks are obviously carbon limited for many species of bacteria. That's why organic carbon dosing works to drive bacteria.

I do not believe there is any evidence that any reef tank at any normal pH (say, less than 8.5) is carbon limited for photosynthesis.

Further, there is lots of evidence to the contrary: Vast numbers of reefers who have tested it themselves by dosing organic carbon. There is no evidence from these experiments that dosing organic carbon (unless it is a special organic that contains N or P) boosts coral or macroalgae growth rates.

You are right again, they couldn’t experience or observed it because they’re tank would of been Carbon limited, that’s why they would start dosing carbon in the first place.

 

[sixty_reefer]

It does not make any sense and is not correct.

I know you strongly believe what you are writing, but I don't want folks reading this to think it is a simple true statement.

What would be stopping the growth of the macro algae in that situation in your opinion. Why do some can grow algae with a flashlight and others need the power of the sun to grow algae in similar parameters conditions?

 

[sixty_reefer]

I'm almost at a lose for words. What prediction did you make that is correct?

You have no evidence that any prediction you have made on any system is accurate except your saying it is true.

You declined to predict what is limiting in the REAL cases I posted where IT IS KNOWN what is limiting.

That's a real test.

Am just trying to promote some health discussion, if you think this thread is going off rails than I don’t mind stopping it here.

 

[sixty_reefer]

Serious and honest question, if Carbon is useless to grow algaes why is it that two of the larger brands of chaeto fertiliser contain Carbon in the chemical analysis.

Is Potassium carbonate a source of carbon also? Out of my league in this one, my chemical knowledge rubbish.

 

[Randy Holmes-Farley]

You are right again, they couldn’t experience or observed it because they’re tank would of been Carbon limited, that’s why they would start dosing carbon in the first place.

Every reef tank (or close to it) is organic carbon limited for heterotrophic bacterial growth. Doesn't take any ratios to know that. Add lots of metabolizable organic matter and bacteria will grow. That's why organic carbon dosing works.

There's likely no reef tank that is soluble organic carbon limited for photosynthetic organisms such as phytoplankton, and macroalgae.

Corals that eat foods (organic matter), and bacteria such as cyanobacterial can be a mixture of results where they do consume foods (organics) and metabolize them to CO2.

 

[Randy Holmes-Farley]

Is Potassium carbonate a source of carbon also? Out of my league in this one, my chemical knowledge rubbish.

Which products?

There are LOADS of bogus products that cannot possibly work or work for the reasons claimed, so pointing to ingredients as evidence of something is often a fail. It's a very serious problem in reefing, and the actual manufacturer of one of those you mention is among the worst fails.

But in this case, if you are talking about the incredibly low level of 0.005% carbon in chaetogro is not in any supplied for carbon sourcing. It is part of the EDTA molecule used to keep the iron soluble:

Brightwell Aquatics - ChaetoGro

Sources of Nutrients​

Potassium sulfate, Calcium chloride, Magnesium sulfate, Potassium iodide, Iron EDTA, Zinc sulfate, Manganese chloride, Sodium tetraborate, Cobalt chloride, Sodium molybdate.

 

[Randy Holmes-Farley]

Is Potassium carbonate a source of carbon also? Out of my league in this one, my chemical knowledge rubbish.

For sure adding carbonate (or bicarbonate) maintains alkalinity and provides the true source of CO2 for many photosynthetic marine organisms: bicarbonate. I discuss the scientific evidence for that in the article I posted earlier:

Photosynthesis and the Reef Aquarium, Part I: Carbon Sources by Randy Holmes-Farley - Reefkeeping.com

 

[Randy Holmes-Farley]

What would be stopping the growth of the macro algae in that situation in your opinion. Why do some can grow algae with a flashlight and others need the power of the sun to grow algae in similar parameters conditions?

Macroalgae and all photosynthetic organisms need a whole host of chemicalls to do the job, N, P, many trace metals such as iron and manganese, light, space, and freedom from herbovires and chemical poisons.

In much of the ocean, it is iron that limits phytoplankton growth and dosing iron to the ocean boosts growth. It is not either N or P or C that individually limits that growth.

 

[sixty_reefer]

@Randy Holmes-Farley thank you it was very productive and informative, there was two theories involving the abundance of Carbon that could cause the algae to bloom, I may have to revisit this particular situation in a later date once I absorb more knowledge on what happens in a high Carbon abundance event. Maybe co2 could become more available in a high C situation helping algaes to thrive and less available in a low C situation reducing growth or stalling, maybe that’s why there is K2O in most chaeto fertilisers to increase co2 availability, k20 reacts with Co2 making K2CO3. in low carbon situations It’s not uncommon to see low ph during algae bloom events
there will be something related just don’t have the answers right now

 

[Randy Holmes-Farley]

There’s no K2O in chaeto fertilizers. That is just a legal requirement for how to indicate how much potassium is present . IMO, it is stupid, but it’s just a unit of measure of potassium.

 

[Randy Holmes-Farley]

For chaetogro, for example,

Guaranteed Analysis​

0-0-1.30; Potassium (K) as Soluble Potash (K2O) (min) 1.30%; Boron 0.009%; Carbon 0.005%; Calcium 0.14%; Chlorine 0.39%; Cobalt 0.0004%; Iron 0.1%; Magnesium 0.4%; Manganese 0.0475%; Molybdenum 0.004%; Sulfur 0.16%; Zinc 0.002%.

 

[sixty_reefer]

There’s no K2O in chaeto fertilizers. That is just a legal requirement for how to indicate how much potassium is present . IMO, it is stupid, but it’s just a unit of measure of potassium.

I’ll find the connection one day, I’m not suffering from GHA at the moment to be able to study it further, I am suffering from Cyanobacteria on the new tank, and have been putting the theory to practice to see what happens, did you saw the Cyanobacteria theory?

 

[sixty_reefer]

I think it’s important to mention that the theoretical formula still stands correct in my opinion, if we look at the first paragraph regarding pest algaes I’ve mentioned that the formula is telling me that there is a high abundance of Carbon, carbon can be in the form of Doc and N-Doc the theoretical formula can’t account for how much of each is available. My mistake was to make a assumption that was Doc the root cause for the issue completely disregarding N-Doc. And we all know what happens wend assumption are made. I apologise for not taking the availability of N-Doc in consideration that could well be the route cause of pest algae’s thriving instead of Doc.
I don’t want for my lack of chemistry knowledge and my assumption to interfere with a potentially good formula that could be good for the hobby.