Do we need Nitrate in a reef tank?

[jda]

What about the amount of protein added per day as a first step in understanding nitrogen availability? The amount of nitrate would be the daily left over. It is a big simplification, but a start to understanding more about the consumption rate.

Maybe, if there were a way to measure this. I have long argued that trying to measure is mostly a fools errand, but educating is better idea so that folks can see the big picture and apply it to what they are seeing in their tanks. Unfortunately, this has not worked. Too few want to do the work of even reading a few paragraphs about different nitrogen and phosphorous sources, the biology of what is of use vs what is a waste product, etc. Having a number from a worthless test is just too hard to overcome. Simple has ruled the day, which upsets me a bit. You see this every time somebody cuts back on feeding to get their no3 or po4 down not knowing that they are limiting available resources... or adds no3 and po4 to the backend to "feed" their corals when their corals.

Redfield is the same way. Even if there could be perfect ratio numbers, there is no way that we can test for the forms that really matters... so some will still care too much and others will realize that it is currently for naught. I could be convinced that a ratio of nitrogen to phosphorous might be helpful, but I see no use in measuring nitrate to phosphate ratios. Most will gravitate to the numbers without even realizing that they are near meaningless.

 

[Randy Holmes-Farley]

with exception when we are dosing nitrate then nitrate is just nitrate.

Maybe, and it is possible (not proven, imo) that adding ammonia to get to that same nitrate might be better, but adding nitrate may provide nitrate for organisms that are happy to consume it, possibly leaving more ammonia for those who don’t care for nitrate.

 

[Lavey29]

Very interesting topic and some well informed replies . We all know each tank is different and the ULNS approach was common some years back. Just from my personal experience, when my nitrates were very low stuff died. Not quickly overnight but when the decline started it was fast. No amount of supplement aminos, other coral food broadcast fed helped. Now over the past year that I have maintained good nitrates levels of 10 to 15, I don't lose any corals, no soft, LPS or even SPS and everything thrives. Obviously other factors are involved here also. I have a good size bioload and I feed heavy so there is ammonia constantly present being processed by bacteria. I think this is the most important element in sustaining an enclosed system over and above any additives we put in the tank. Just my .02.

 

[Dan_P]

There is many subjects that folks find irrelevant. Unfortunately your claim is not shared by many therefore irrelevant for the discussion without being elaborated further, some like myself like to understand why nutrients get out of balance.

Fair enough, but consider Bigfoot sightings are also relevant to many folks even though like nutrient ratios have no supporting evidence. Nutrient ratios are irrelevant simply because there is no connection between a successful aquarium and nutrient ratio.

 

[Dan_P]

Maybe, if there were a way to measure this. I have long argued that trying to measure is mostly a fools errand, but educating is better idea so that folks can see the big picture and apply it to what they are seeing in their tanks. Unfortunately, this has not worked. Too few want to do the work of even reading a few paragraphs about different nitrogen and phosphorous sources, the biology of what is of use vs what is a waste product, etc. Having a number from a worthless test is just too hard to overcome. Simple has ruled the day, which upsets me a bit. You see this every time somebody cuts back on feeding to get their no3 or po4 down not knowing that they are limiting available resources... or adds no3 and po4 to the backend to "feed" their corals when their corals.

Redfield is the same way. Even if there could be perfect ratio numbers, there is no way that we can test for the forms that really matters... so some will still care too much and others will realize that it is currently for naught. I could be convinced that a ratio of nitrogen to phosphorous might be helpful, but I see no use in measuring nitrate to phosphate ratios. Most will gravitate to the numbers without even realizing that they are near meaningless.

There are estimates for many frozen foods and measurements on commercial food packages for protein content. Maybe we could use that as one more bit of information about the N and P input. There must be a correlation between N in food and waste N in the water. Ditto P and phosphate. And I think we can assume causation when we increase feeding and see more waste N, like nitrate.

 

[jda]

You might be able to formulate something with protein. Each time that food is eaten, about 1/3 of the good stuff is retained. Food is eaten about 3x over by fish, on average. Eventually, you get 1/3 of the way to nothing every time with a pretty easy limit theorem. I don't know how much is retained permanently by each operator from large to small - I have never seen anything on this.

You cannot assume that increased feeding leads to more N, or the inverse that increased N came from more feeding. Increased feeding most likely increases aerobic (@sixty_reefer) and anaerobic bacterial populations and you should equilibrium back to near-zero soon. I have a mature sandbed and rocks that pull their weight and you could feed a kilo of mysis to my tank a day and the no3 would barely move and even if it did, the bacteria would eventually catch up and bring it back to zero quite quickly. Maybe a kilo is too much, but you get the point... I once dropped a whole Eheim auto feeder of pellets in the tank at once (bad day) and the no3 did not move... po4 went up a bit, but then back down once the chaeto caught back up. Again, I think that all that you can conclude is that you don't have enough bacteria to process the extra no3 yet.

For example, people used to neglect their sand beds for many years or a decade. Eventually, the no3 would start to rise when the sand was so full of inert gunk that there was no more place for the anoxic bacteria to live in sufficient numbers. If the sand was vacuumed and the gunk removed, the anoxic bacteria would repopulate and lower no3 numbers again. People called sand beds time bombs for this (and their laziness exporting po4 when the sand could not longer mask their stupid husbandry), but it was the hobbyist, not the sand. Lack of maintenance led to these rising no3 n numbers, not food.

Another example that you can see this nowadays with dry/dead rock. no3 is present for a few years (guessing). Later, the microfauna cleans the terrestrial organics out of the rock and it can start to get anoxic zones into the pores and structure. People post that they cannot keep no3 up anymore. This also has nothing to do with food.

 

[jda]

Maybe, and it is possible (not proven, imo) that adding ammonia to get to that same nitrate might be better, but adding nitrate may provide nitrate for organisms that are happy to consume it, possibly leaving more ammonia for those who don’t care for nitrate.

I guess that since you said may and possibly, this is a just a supposition? If not, I would like to read more about this and which organisms have this capability. I have only read that the few things that we know that use no3 directly (macro algae, tridacnia) will also take as much ammonia as they can.

 

[mbmartin06]

Unfortunately, this has not worked. Too few want to do the work of even reading a few paragraphs about different nitrogen and phosphorous sources, the biology of what is of use vs what is a waste product, etc.

where is a good place to start reading up on the biology of this. Looking for journal links or keywords to search.

 

[sixty_reefer]

Fair enough, but consider Bigfoot sightings are also relevant to many folks even though like nutrient ratios have no supporting evidence. Nutrient ratios are irrelevant simply because there is no connection between a successful aquarium and nutrient ratio.

Not knowing how to interpret is different from being irrelevant.
there’s not one autotrophic or heterotrophic organisms that can survive in this planet without being affected by nutrient limitations.

 

[sixty_reefer]

You might be able to formulate something with protein. Each time that food is eaten, about 1/3 of the good stuff is retained. Food is eaten about 3x over by fish, on average. Eventually, you get 1/3 of the way to nothing every time with a pretty easy limit theorem. I don't know how much is retained permanently by each operator from large to small - I have never seen anything on this.

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

You cannot assume that increased feeding leads to more N, or the inverse that increased N came from more feeding. Increased feeding most likely increases aerobic (@sixty_reefer) and anaerobic bacterial populations and you should equilibrium back to near-zero soon. I have a mature sandbed and rocks that pull their weight and you could feed a kilo of mysis to my tank a day and the no3 would barely move and even if it did, the bacteria would eventually catch up and bring it back to zero quite quickly. Maybe a kilo is too much, but you get the point... I once dropped a whole Eheim auto feeder of pellets in the tank at once (bad day) and the no3 did not move... po4 went up a bit, but then back down once the chaeto caught back up. Again, I think that all that you can conclude is that you don't have enough bacteria to process the extra no3 yet.

For example, people used to neglect their sand beds for many years or a decade. Eventually, the no3 would start to rise when the sand was so full of inert gunk that there was no more place for the anoxic bacteria to live in sufficient numbers. If the sand was vacuumed and the gunk removed, the anoxic bacteria would repopulate and lower no3 numbers again. People called sand beds time bombs for this (and their laziness exporting po4 when the sand could not longer mask their stupid husbandry), but it was the hobbyist, not the sand. Lack of maintenance led to these rising no3 n numbers, not food.

Another example that you can see this nowadays with dry/dead rock. no3 is present for a few years (guessing). Later, the microfauna cleans the terrestrial organics out of the rock and it can start to get anoxic zones into the pores and structure. People post that they cannot keep no3 up anymore. This also has nothing to do with food.

Taking that many food manufacturers don’t respect the CNP balance found in nature and have a higher nitrogen and phosphates content Vs organic carbon content it’s complicated for me to answer this.

As a basic answer Is that every food has a organic carbon content (carbohydrates) that will determine how much nitrogen and phosphorus heterotrophic bacteria can assimilate, the rest of the nitrogen and phosphorus usually has to be removed via GFO and denitrification to keep the system balanced in a average mature system. Poor organic carbon content in foods it’s what thrive the industry as GFO and GAC become a necessity in many households that don’t realise how poor is the organic carbon content in foods is.

 

[biom]

Maybe, and it is possible (not proven, imo) that adding ammonia to get to that same nitrate might be better, but adding nitrate may provide nitrate for organisms that are happy to consume it, possibly leaving more ammonia for those who don’t care for nitrate.

But adverse effect is possible too - by adding nitrate to increase the number of "nitrate comfortable" organisms and they to stripe off water from all the other nitrogen forms.

 

[biom]

Poor organic carbon content in foods it’s what thrive the industry as GFO and GAC become a necessity in many households that don’t realise how poor is the organic carbon content in foods is.

I dont see much of conspiracy here. Fish food supply for the saltwater aquariums in the word is probably the daily allowance of a single fish farm in Norway. Fish food is made for fish and most of the fish in the hobby are carnivorous which means the C:N: P ratio in their food should be much different from ratio one want to see in their aquarium water if you want heathy fish. And not to forget many reefers feed with frozen natural food - coppepods, mysis, mussel, artemia and still have (even worse) nutrient disbalance. I dont believe industry thrive on GFO or GAC either.

 

[sixty_reefer]

I dont see much of conspiracy here. Fish food supply for the saltwater aquariums in the word is probably the daily allowance of a single fish farm in Norway. Fish food is made for fish and most of the fish in the hobby are carnivorous which means the C:N: P ratio in their food should be much different from ratio one want to see in their aquarium water if you want heathy fish. And not to forget many reefers feed with frozen natural food - coppepods, mysis, mussel, artemia and still have (even worse) nutrient disbalance. I dont believe industry thrive on GFO or GAC either.

Not a conspiracy, just something that some vendors don’t take into account, pellet and flake tend to be fairly high in protein and phosphorus in comparison to other organisms that the fish would eat in it’s natural environment.
this high protein diets aren’t usually a issue as long as there is enough filtration to balance the excess nitrogen produced from this diets.

The imbalance in many systems can be easily corrected by balancing the import of the 3 nutrients taking that all big 3 are connected in relation to heterotrophic filtration. Adding complex carbohydrate to the food being added to the system is one of the most effective ways to reduce pollutants associated with yelling of the water for example.

 

[Randy Holmes-Farley]

I guess that since you said may and possibly, this is a just a supposition? If not, I would like to read more about this and which organisms have this capability. I have only read that the few things that we know that use no3 directly (macro algae, tridacnia) will also take as much ammonia as they can.

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.

If one just supposes that the ammonia concentration where that switchover happens varies by organism, then there will be some concentration of nitrate where some organisms are using it and some organisms are using ammonia. If no nitrate were available, they’d all be going for the same ammonia.

I would propose a thought experiment: if nitrate was such an undesirable N source that it hurt organisms when they used it, why are there not a large number of reports of negative results when initiating nitrate dosing?

Clearly the nitrate is being consumed in most cases. What visible harms are happening?

 

[jda]

Of course it does not hurt things in reasonable numbers. Of course the ones who can use it can handle it. Of course the things that cannot use it still will not.

There were plenty of report of bad things happening when people started to dose no3. If you want to argue that it was application over compound (not stump remover), then I won't push back too much... but there were issues with algae blooms, darkening of corals, loss of some inverts, etc. If we are talking anecdotes here, there are plenty of folks who think that they saw improvement with no3 dosing that switched from no3 to ammonium and got even better results. I am not discounting anecdotes since it is often all that we have in the hobby, but who gives the anecdotes matters - after all, people claimed that dosing Vibrant really made their bacterial populations take off (like they could possibly know this even if it did). I should also mention (again) that my friends keep and my interest is in stonies and clams, so I do tend to neglect other types of non true coral beyond a few zoas, mushrooms and 'nems that I keep mostly to trade.

There could be harm if people misunderstood and only dosed no3 and cut back on other forms of nitrogen. Again, application over compound probably... but is this not a reef2reef basic?

I was just asking since there appears to be no evidence that macro algae and tridacna stop using ammonia even with large amounts of no3 available. The evidence is the contrary that they gather whatever they can in whatever form. I just wanted to study and read if you saw otherwise. It is not like these are some sort of nice neighbors who take just enough to survive and leave the rest for their friends on the reef... if they have capability to gather X amount of no3 and Y of nh[3,4], then max both out.

 

[sixty_reefer]

@jda this is a study on a nuisance that many aquarists encounter regarding nutrient preferences

Nitrogen uptake by the macro-algae Cladophora coelothrix and Cladophora parriaudii: Influence on growth, nitrogen preference and biochemical composition

The capacity of macro-algae to remove nutrients means they have the potential to concomitantly bioremediate polluted waters and generate exploitable b…

www.sciencedirect.com

 

[Spare time]

Can you give some more details or direct to thread on this, this statement sounds interesting and more info will be appreciated.

Eh its all anecdotal. No one seems to know the answer, and so this is based off of the hundreds of anecdotes I have seen where nitrate doesn't seem to matter as much as phosphate when it comes to dinos.

 

[jda]

where is a good place to start reading up on the biology of this. Looking for journal links or keywords to search.

Read some of the posts on this thread. A good place to start. If you just basically know that nitrate is different than nitrogen and phosphate is different than phosphorous than you are way ahead of most. Add in that none of these are food for corals and sugars/carbs/carbon is needed or that. True corals mostly don't use nitrate but need nitrogen from other sources. Some things like macro algae can use nitrate directly but also from other sources too. Zoox are dinos which are micro algae - kill dinos in the tank and dinos in host can suffer too, even though the hosts can offer some sort of protection. Micro algae is not even remotely the same as macro algae.

There are no studies or journal stuff that brings it all together. Even the link that sixty linked above is helpful, but I would not apply that to more common aquarium algae like chaetomorpha or halmedia without more details. This is worth a read and thought, but don't assume that it goes beyond those algae family types. As you read a few more of these for other types, you can see if there are similarities.

Follow @Lasse if you want some good stuff. He is a good link/study poster but also can take the stuff in the links and apply it as good as anybody. Too often, studies are linked and assumed to translate at face value to the hobby with too many unknowns. Takes a special person to transition from academia to application.

Some basic chem or bio is a good start too. If more understood that nitrogen and phosphorous are building blocks or organic life and not "food" for corals. I find it totally disgusting that people are dosing no3 and po4 to "feed'" their corals and then asking if they can use LEDs with 25 PAR to light with.

 

[mbmartin06]

Read some of the posts on this thread. A good place to start. If you just basically know that nitrate is different than nitrogen and phosphate is different than phosphorous than you are way ahead of most. Add in that none of these are food for corals and sugars/carbs/carbon is needed or that. True corals mostly don't use nitrate but need nitrogen from other sources. Some things like macro algae can use nitrate directly but also from other sources too. Zoox are dinos which are micro algae - kill dinos in the tank and dinos in host can suffer too, even though the hosts can offer some sort of protection. Micro algae is not even remotely the same as macro algae.

There are no studies or journal stuff that brings it all together. Even the link that sixty linked above is helpful, but I would not apply that to more common aquarium algae like chaetomorpha or halmedia without more details. This is worth a read and thought, but don't assume that it goes beyond those algae family types. As you read a few more of these for other types, you can see if there are similarities.

Follow @Lasse if you want some good stuff. He is a good link/study poster but also can take the stuff in the links and apply it as good as anybody. Too often, studies are linked and assumed to translate at face value to the hobby with too many unknowns. Takes a special person to transition from academia to application.

Some basic chem or bio is a good start too. If more understood that nitrogen and phosphorous are building blocks or organic life and not "food" for corals. I find it totally disgusting that people are dosing no3 and po4 to "feed'" their corals and then asking if they can use LEDs with 25 PAR to light with.

Thanks. I pretty much read everything I can on here but tend to go the “trust but verify” route. Obviously I read more into information from some people than others. Been a few years and think I have them fairly pegged. I read a lot of what lasse posts. I’ll keep digging.

 

[sixty_reefer]

There are no studies or journal stuff that brings it all together. Even the link that sixty linked above is helpful, but I would not apply that to more common aquarium algae like chaetomorpha or halmedia without more details. This is worth a read and thought, but don't assume that it goes beyond those algae family types. As you read a few more of these for other types, you can see if there are similarities.

Chaetomorpha linum in the bioremediation of aquaculture wastewater: Optimization of nutrient removal efficiency at the laboratory scale

Marine pollution from aquaculture wastewater is a widespread and increasing ecological problem. Algae, with their ability to remove surplus nutrients …

www.sciencedirect.com

This article is on chaeto it demonstrates that algae’s including the traditional used in reef aquaria filtration will prefer ammonium over nitrates only once ammonia is down they change to nitrates.
This article actually suggests a double algae bed for a more efficient filtration system one to remove ammonia and a second one to remove nitrates.
This is one of the reasons I don’t find useful to include algae beds in mature coral systems due to the nitrogen competition.