Do we need Nitrate in a reef tank?

[Randy Holmes-Farley]

I guess I do not see the trend that dosing nitrate causes issues. More often than not, folks report improvements. Of course, they might see the same or better improvement dosing ammonia.

I’m not aware of any published data that really bears on the question of whether dosing nitrate causes issues in reef aquaria.

 

[Lasse]

the number agreed by many biologists is around 90% of the nutrients consumed by heterotrophic organism is lost via waste between trophic levels.

10% into biomass in each step of the food chain is valid for warmblooded animals like mammals and birds -for cold blooded - the corresponding factor is around 20 - 25 %.

I think it is self evident that if an organism can use both nitrate and ammonia, that at some level of nitrate and some lower or much lower level of ammonia, it will be taking up nitrate.

Yes but i cost energy. Is it more energy involved in the conversion of NO3-N into organic N forms than a conversion of NH3-N/NH4-N into organic N. IMO - it means that if an organism can use both sources for N - it will take the less energy demanding species first.

I think we can learn a little from fresh water planted aquariums. They never use NH3/NH4 as nitrogen source - they use NO3. The reason for this is that it have shown up that the problem with some microalgae disappear - some of them are not able to use NO3 as a N source - they lack nitrate and nitrite reductase. I have seen some literature that indicate that cyanobacteria can´t use NO3 - they either produce their own NH3/NH4 or use NH3/NH4 in the water. There is some aquarium reports that state that dosing amino acids provoke cyanobacteria blooms - interesting facts here is that amino acids move as freely through cell membranes as NH3/NH4

Sincerely Lasse

 

[sixty_reefer]

10% into biomass in each step of the food chain is valid for warmblooded animals like mammals and birds -for cold blooded - the corresponding factor is around 20 - 25 %.



Yes but i cost energy. Is it more energy involved in the conversion of NO3-N into organic N forms than a conversion of NH3-N/NH4-N into organic N. IMO - it means that if an organism can use both sources for N - it will take the less energy demanding species first.

I think we can learn a little from fresh water planted aquariums. They never use NH3/NH4 as nitrogen source - they use NO3. The reason for this is that it have shown up that the problem with some microalgae disappear - some of them are not able to use NO3 as a N source - they lack nitrate and nitrite reductase. I have seen some literature that indicate that cyanobacteria can´t use NO3 - they either produce their own NH3/NH4 or use NH3/NH4 in the water. There is some aquarium reports that state that dosing amino acids provoke cyanobacteria blooms - interesting facts here is that amino acids move as freely through cell membranes as NH3/NH4

Sincerely Lasse

The webinar I saw only mentioned a average of 10 to 15 percentile for aquatic organisms although I didn’t know their individual numbers.

I read an article on Cyanobacteria that mentioned that to convert n2 into NH4 is an energy costly process similar to reconvert No3 to Nh4 leaving nh4 from the water column the most effective method of assimilation.

 

[Randy Holmes-Farley]

10% into biomass in each step of the food chain is valid for warmblooded animals like mammals and birds -for cold blooded - the corresponding factor is around 20 - 25 %.



Yes but i cost energy. Is it more energy involved in the conversion of NO3-N into organic N forms than a conversion of NH3-N/NH4-N into organic N. IMO - it means that if an organism can use both sources for N - it will take the less energy demanding species first.

I think we can learn a little from fresh water planted aquariums. They never use NH3/NH4 as nitrogen source - they use NO3. The reason for this is that it have shown up that the problem with some microalgae disappear - some of them are not able to use NO3 as a N source - they lack nitrate and nitrite reductase. I have seen some literature that indicate that cyanobacteria can´t use NO3 - they either produce their own NH3/NH4 or use NH3/NH4 in the water. There is some aquarium reports that state that dosing amino acids provoke cyanobacteria blooms - interesting facts here is that amino acids move as freely through cell membranes as NH3/NH4

Sincerely Lasse

I do not believe it is correct that amino acids freely cross membranes by diffusion. They must be taken across membranes by transporters. Ammonium also cannot cross, but uncharged NH3 can.

“Small uncharged molecules can diffuse freely through a phospholipid bilayer. However, the bilayer is impermeable to larger polar molecules (such as glucose and amino acids) and to ions.”

Cell Membranes - The Cell - NCBI Bookshelf

The structure and function of cells are critically dependent on membranes, which not only separate the interior of the cell from its environment but also define the internal compartments of eukaryotic cells, including the nucleus and cytoplasmic organelles. The formation of biological membranes...

www.ncbi.nlm.nih.gov

 

[Randy Holmes-Farley]

I also think it is not always correct (and may rarely be correct) to assume ammonia is taken up be passive diffusion rather than by active uptake:

“At extracellular concentrations of ammonium less than 1 mM, microbes require transport systems such as ammonium transporters (Amts)”

FWIW, 1 mM = 17 ppm NH3.

Exaggerated trans-membrane charge of ammonium transporters in nutrient-poor marine environments

Transporter proteins are a vital interface between cells and their environment. In nutrient-limited environments, microbes with transporters that are effective at bringing substrates into their cells will gain a competitive advantage over variants with ...

www.ncbi.nlm.nih.gov

 

[jda]

I don't think that anybody says that it causes issues, within reason. However, it also probably does not help in the ways that people think that it does. If more understood about what is happening, then they might choose different routes for nitrogen that probably work better.

 

[Randy Holmes-Farley]

I don't think that anybody says that it causes issues, within reason. However, it also probably does not help in the ways that people think that it does. If more understood about what is happening, then they might choose different routes for nitrogen that probably work better.

What procedure do you recommend when nitrate is undetectable and phosphate is normal or high?

 

[Lasse]

I do not believe it is correct that amino acids freely cross membranes by diffusion. They must be taken across membranes by transporters. Ammonium also cannot cross, but uncharged NH3 can.

“Small uncharged molecules can diffuse freely through a phospholipid bilayer. However, the bilayer is impermeable to larger polar molecules (such as glucose and amino acids) and to ions.”

Cell Membranes - The Cell - NCBI Bookshelf

The structure and function of cells are critically dependent on membranes, which not only separate the interior of the cell from its environment but also define the internal compartments of eukaryotic cells, including the nucleus and cytoplasmic organelles. The formation of biological membranes...

www.ncbi.nlm.nih.gov

I did not meant that it was diffusion - I use the sentence "freely as NH4/NH3" Maybe wrong words but I meant that they pass membranes as good as NH4/NH3 complex. This is a knowledge that I got from a fellow reefer here in Sweden - he did is PhD thesis around N transports through cell membranes, Unfortunately, he is not longer active and I have lost contact with him - I´m not able to confirm this.

I also use NH3/NH4 because I see it as an interchangeable komplex - especially in interfaces (between water/air, cell membranes and other barriers) there the NH3 molecule can pass by "osmosis" - depended of different concentrations ar each side of the interface. If a NH3 molecule pass to the other side of an interface - the rest of of the complex (on the side that lose a molecule) will adjust according to the pH to the same percentage NH3 contra NH4 as before the barrier crossing and new NH3 molecules can cross and so on

I also think it is not always correct (and may rarely be correct) to assume ammonia is taken up be passive diffusion rather than by active uptake:

“At extracellular concentrations of ammonium less than 1 mM, microbes require transport systems such as ammonium transporters (Amts)”

FWIW, 1 mM = 17 ppm NH3.

Exaggerated trans-membrane charge of ammonium transporters in nutrient-poor marine environments

Transporter proteins are a vital interface between cells and their environment. In nutrient-limited environments, microbes with transporters that are effective at bringing substrates into their cells will gain a competitive advantage over variants with ...

www.ncbi.nlm.nih.gov

This surprise me -17 mg/L NH4 is not really a low nutrient environment

Sincerely Lasse

 

[jda]

What procedure do you recommend when nitrate is undetectable and phosphate is normal or high?

Export more phosphate. I am a natural guy, so I grow chaeto, which works very well in conjunction with multiple skimmers. 1-3 ppb is where my po4 has been for many years... like all the way back to when Hannah Ultra Low hit the market. As you likely remember, I do not suggest chaeto if po4 or no3 is too high since I have seen it slow down too much - you did not agree with my observations.

For media people, I used to recommend GFO, but I fear that the reason why it was so harmful to some users is that it strips meta and ortho and leaves only organically bound phosphorous for things to use and not all things probably can. I lean towards the smart use of LC now since it appears to leave polyphosphates in the tank for organisms to use.

If you are suggesting that nitrate is needed for organic carbon dosing to work, then cool. This is not really in my wheelhouse in a reef tank - only ever used it in a fish only. However, I would still suggest ammonia so that you could get used along the entire route to nitrogen gas... find more things to use the carbon along the way.

For me, I don't care how much nitrate comes out of any cycle - my rock and sand can take care all of it down to a trace.

 

[Randy Holmes-Farley]

Export more phosphate. I am a natural guy, so I grow chaeto, which works very well in conjunction with multiple skimmers. 1-3 ppb is where my po4 has been for many years... like all the way back to when Hannah Ultra Low hit the market. As you likely remember, I do not suggest chaeto if po4 or no3 is too high since I have seen it slow down too much - you did not agree with my observations.

For media people, I used to recommend GFO, but I fear that the reason why it was so harmful to some users is that it strips meta and ortho and leaves only organically bound phosphorous for things to use and not all things probably can. I lean towards the smart use of LC now since it appears to leave polyphosphates in the tank for organisms to use.

If you are suggesting that nitrate is needed for organic carbon dosing to work, then cool. This is not really in my wheelhouse in a reef tank - only ever used it in a fish only. However, I would still suggest ammonia so that you could get used along the entire route to nitrogen gas... find more things to use the carbon along the way.

For me, I don't care how much nitrate comes out of any cycle - my rock and sand can take care all of it down to a trace.

When N is possibly insufficient, how do you recognize that situation and what do you do about it if there is no obvious N export to reduce (say, by organic carbon dosing or macroalgae).

 

[ghostandhyde]

I’m starting zeovit up now. I used it for years with success. I could keep nitrate at .2 consistently until the stones were not able to keep up (6-8 weeks). Then I would see the nitrate rise And I would add/replace stones. I’m not a scientist so that’s about all you will get out of me.

 

[livinlifeinBKK]

I think the takeaway here is that corals need nitrogen. Since nitrate is a source of nitrogen (which is able to be used by corals), nitrate provides nitrogen with low toxicity. While you may be able to substitute another nitrogen source for nitrate, that doesn't change the fact that nitrate is utilized by corals as well. So, in conclusion, perhaps your corals won't die with 0 nitrate as long as you provide an alternative source of nitrogen.
I'm kind of curious what the reason was for asking though...is there a reason you would want 0 nitrate? The question seems to imply that maybe we don't want any nitrate at all present which seems very unnatural to say the least...

 

[jda]

When N is possibly insufficient, how do you recognize that situation and what do you do about it if there is no obvious N export to reduce (say, by organic carbon dosing or macroalgae).

I might be misunderstanding the question, but I don't do anything to directly reduce N. I don't care how much gets through the cycle since my rocks and sand will crush anything that gets there.

How do I recognize what to do? I don't. Nobody can. Just like having residual no3 is no indication of having available nitrogen in other preferred forms without a bunch of assumptions, I just assume that coralline covering my front glass every few weeks, corals growing like crazy and having to divide my chaeto in half quite often is a good thing.

 

[jda]

I think the takeaway here is that corals need nitrogen. Since nitrate is a source of nitrogen (which is able to be used by corals), nitrate provides nitrogen with low toxicity. While you may be able to substitute another nitrogen source for nitrate, that doesn't change the fact that nitrate is utilized by corals as well. So, in conclusion, perhaps your corals won't die with 0 nitrate as long as you provide an alternative source of nitrogen.
I'm kind of curious what the reason was for asking though...is there a reason you would want 0 nitrate? The question seems to imply that maybe we don't want any nitrate at all present which seems very unnatural to say the least...

It is not likely that true coral (skeleton leavers) can use nitrate very well - and those hosts that can covert no3 back to a usable form (not all) do so at a significant cost that nobody really knows but in the range of 30-70% more energy (reports vary). True coral only use nitrate when there is not any other nitrogen sources around - it is not preferred. For a corals struggling to survive, this energy expenditure can be really hard. True coral are better off with ammoni[a,um] and the larger specimens can likely get significant nitrogen from bacteria caught and assimilated in their slime coats.

It is more accurate to say that you can substitute no3 for other nitrogen sources like ammonium for true coral... but with the energy caveats above.

I am not a huge expert on non-coral like softies since I don't keep them. Nems do get nitrogen from ammonia and no2, IIRC. Clams and macro algae can use nitrate directly with little cost.

Near-zero nitrate is very common in tanks with sand beds and good live rock that house anoxic bacteria that turn no3 into nitrogen gas - this completes the nitrogen cycle. The bacteria colonize to equilibrium leaving a trace, but keeping the levels very low. The people who you see that add no3 every day and are back down to zero the next day are like because of this unless they are growing massive amounts of macro algae. Nobody shoots for this, it just happens... and it has worked fine for decades as long as people keep feeding their fish well.

 

[biom]

I've tried to extract some information from papers of Grover et al. (2002,2003,2006, and 2008)

Stony corals (at least S. pistillata) prefer ammonium compared with nitrate (uptake rates of one order of magnitude higher) but they still can uptake nitrate in a rate higher than amino acids and much higher than urea. The coral will not use or use in much lower rate nitrate if there is ammonium above certain threshold (>1 uM or 0.018 mg/l) because their nitrate reductase may be repressed by ammonium.

Incorporation of nitrogen in corals was already saturated at 1uM (0.018 mg/l) ammonium (Grover et al, 2002). Uptake rates of nitrogen were not different between 1 and 5 uM ammonium

This does not seem to be the case for all anthozoans, since Wilkerson and Muscatine (1984) found no uptake of nitrate by Aiptasia pulchella, even when animals were pretreated for 24 h or 1 month with 10 uM NO3.

***
It looks like the SPS will take nitrate with a good rate but only if there is no ammonium available. And 0.02 mg/l ammonium is more than enough to make SPS corals happy. It is possible that sea anemones at least Aiptasia may not be able to assimilate nitrate.

 

[biom]

Clams and macro algae can use nitrate directly with little cost.

The cost in terms of energy is the same as for the corals, macroalgae also prefer ammonia, they can use both simultaneously but still nitrate uptake is suppressed in presence of ammoni/a/um

 

[jda]

True coral can also get nitrogen and phosphorous with good efficiency through micro things that it catches in their slime coats - think bacteria. This is easer with larger specimens since they don't use a surface area math equation like small frags do.

Ability to catch and process larger food through polyps varies with species, but is not very efficient in nature and probably costs energy in captivity for most - if you see a study or paper saying that some species benefited, do not assume that this translates to others.

The cost in terms of energy is the same as for the corals, macroalgae also prefer ammonia, they can use both simultaneously but still nitrate uptake is suppressed in presence of ammoni/a/um

Thanks. I had not read that macro used high energy to convert no3, but I believe you and will add this to my calculus. BTW - we adopted 2 girls from Smolyan... I did not see too many reef tanks there in the mountains.

 

[livinlifeinBKK]

It is not likely that true coral (skeleton leavers) can use nitrate very well - and those hosts that can covert no3 back to a usable form (not all) do so at a significant cost that nobody really knows but in the range of 30-70% more energy (reports vary). True coral only use nitrate when there is not any other nitrogen sources around - it is not preferred. For a corals struggling to survive, this energy expenditure can be really hard. True coral are better off with ammoni[a,um] and the larger specimens can likely get significant nitrogen from bacteria caught and assimilated in their slime coats.

It is more accurate to say that you can substitute no3 for other nitrogen sources like ammonium for true coral... but with the energy caveats above.

I am not a huge expert on non-coral like softies since I don't keep them. Nems do get nitrogen from ammonia and no2, IIRC. Clams and macro algae can use nitrate directly with little cost.

Near-zero nitrate is very common in tanks with sand beds and good live rock that house anoxic bacteria that turn no3 into nitrogen gas - this completes the nitrogen cycle. The bacteria colonize to equilibrium leaving a trace, but keeping the levels very low. The people who you see that add no3 every day and are back down to zero the next day are like because of this unless they are growing massive amounts of macro algae. Nobody shoots for this, it just happens... and it has worked fine for decades as long as people keep feeding their fish well.

I really don't think the energy caveats are a concern for the average reefer...i feel my comment was pretty accurate even after rereading it...are the energy caveats something you're measuring daily or weekly and how significant are they exactly? Btw, you do realize that we're talking about the coral holobiont, right? That includes zooxanthellae...

 

[jda]

Zoox/dinos, as well as most other microalgae, cannot use no3. The host has to convert it for them... and use much energy in the process. As @biom posted above, coral will not use no3 unless they have to since it is bad for them. You only need a trace of ammonium for true coral to ignore no3. It is very possible that none of your true coral use no3 at all if you have fish and are feeding them, which is why I think that it is a waste to add it, unless you want to growth-limit cyano or dinos.

In one of the papers that I read, they mentioned humans on the brink of survival running a marathon to eat a meal vs just eating a meal right in front of you. Maybe that was an in-person talk. That was a long time back.

As for energy, I could write paragraphs on this and the hobby today. I see too many people talking about feeding their corals with no3 and po4 and not needing very much light because of it... Energy is a scare resource in our tanks with low carbs/sugars/OC and probably just enough light being supplied. I would consider energy a big deal.

 

[livinlifeinBKK]

Zoox/dinos, as well as most other microalgae, cannot use no3. The host has to convert it for them... and use much energy in the process. As @biom posted above, coral will not use no3 unless they have to since it is bad for them. You only need a trace of ammonium for true coral to ignore no3. It is very possible that none of your true coral use no3 at all if you have fish and are feeding them, which is why I think that it is a waste to add it, unless you want to growth-limit cyano or dinos.

In one of the papers that I read, they mentioned humans on the brink of survival running a marathon to eat a meal vs just eating a meal right in front of you. Maybe that was an in-person talk. That was a long time back.

As for energy, I could write paragraphs on this and the hobby today. I see too many people talking about feeding their corals with no3 and po4 and not needing very much light because of it... Energy is a scare resource in our tanks with low carbs/sugars/OC and probably just enough light being supplied. I would consider energy a big deal.

Really? Why is it that increased nitrate is directly correlated with a substantial increase in zooxanthellae populations?