An important issue to take into account when dosing nitrate is related to the bacterial species able to use it. Denitrifying bacteria require either an anoxic environment or very low amounts of oxygen. If you don't have this almost anoxic environment (for instance because the live rock is saturated and can't hold larger amounts of anaerobic bacteria) then you won't be able to grow the bacterial species that may take advantage of nitrate.
Nitrate as a useful addition for systems utilizing carbon dosing
- Thread starter alexander_ktn
- Start date
Regarding the heterotrophic bacteria
that does not mean they won't use the nitrate
Of course that's what facultative means; I said they were facultative.
They'd be stupid not to prefer the substance that can be oxidized easily,
Stupid or not the bacteria use ammonia preferentially. As such their use of NO3 is also inhibited by ammonium,IMO as they have less need for the NO3 for N just as other organisms do when they get it from ammonia.
The study you cited doesn't say :
So if one wants to add a nitrogen source that does not directly end up in the corals and rather feeds the bacteria, nitrate might be the better choice.
It doesn't say much about bacteria at all. So while the study is interesting.particulary the role of transporters, it doesn't support the extrapolation that since corals take up less nitrate when ammonia is present then nitrate is a better source for bacteria since bact\reria have the same prefernce.
There is no reason to believe ammonium will go to corals and be ignored by heterotrophic bacteria that use it preferentially for N.
As for ammino acids like aspartate they are broken down in an organism and /or used building blocks for various protetns; it's not as if adding them provides free ammonium to the aquarium directly.
To be clear ,I think using a nitrogen source(sodium nitrate, potassium nitrate or an ammino acid ) for a tank with a nitrogen deficiency is ok Tanks will vary . I'd like to hear from someone who is currently using a nitrogen source and has done so long term. Didn't get teh result I had hoped for when I tried it.
that does not mean they won't use the nitrate
Of course that's what facultative means; I said they were facultative.
They'd be stupid not to prefer the substance that can be oxidized easily,
Stupid or not the bacteria use ammonia preferentially. As such their use of NO3 is also inhibited by ammonium,IMO as they have less need for the NO3 for N just as other organisms do when they get it from ammonia.
The study you cited doesn't say :
So if one wants to add a nitrogen source that does not directly end up in the corals and rather feeds the bacteria, nitrate might be the better choice.
It doesn't say much about bacteria at all. So while the study is interesting.particulary the role of transporters, it doesn't support the extrapolation that since corals take up less nitrate when ammonia is present then nitrate is a better source for bacteria since bact\reria have the same prefernce.
There is no reason to believe ammonium will go to corals and be ignored by heterotrophic bacteria that use it preferentially for N.
As for ammino acids like aspartate they are broken down in an organism and /or used building blocks for various protetns; it's not as if adding them provides free ammonium to the aquarium directly.
To be clear ,I think using a nitrogen source(sodium nitrate, potassium nitrate or an ammino acid ) for a tank with a nitrogen deficiency is ok Tanks will vary . I'd like to hear from someone who is currently using a nitrogen source and has done so long term. Didn't get teh result I had hoped for when I tried it.
alexander_ktn
New member
I'm sorry but that's not what inhibition means in this context. I know you want to be right but I even asked a friend who is a biologist at the University of Ankara if he knows of any instance or study that would point to the fact that heterotrophic bacteria will not take up available nitrate if ammonia is present and he even searched a database (that's why my answer took so long) if there are any studies done about exactly that subject. There is no question to him that the bacteria will consume all the available nitrogen sources and multiply until they are either at a limiting minimum value or some other limiting factor comes into play.
The corals are inhibited, that means as long as they can get their nitrogen through other sources (i.e. ammonia or feeding) the nitrate uptake will be at a very low and constant value no matter how much nitrate is in the water (within reasonable limits of course). They cannot or will not take more.
The study I cited in the first post does not say anything much about bacteria because it is not about heterotrophic denitrification but about nutrient uptake by corals... There are other studies that deal with that. I cited it because contrary to ammonia/ammonium the nitrate uptake by corals does not increase with concentration, something quite important in an aquarium context.
As for free ammonium: I said "free ammonium while being broken down", I never said "into the water" - while it is reasonable to think that some part might end up in the water (like happens when fish break down their food) I did not intend to imply that all ammonia from the degradation of amino acids will land in the water. English is not my first language, so that might have played a role in my sentence having been unclear.
I don't want to be right ; I want the information to be right.
The study you cited which has as it's goals examination of phosphate uptake not nitrate uptake by bacteria or corals actually says:
. On the contrary, it is well-known, forexample, that nitrate uptake is generally inhibited in the presence of
ammonium (Badgley et al., 2006; Domotor and D’Elia, 1984; Grover
et al., 2003), either through a repression of the nitrate reductase (Berges
and Harrison, 1995; Guerrero et al., 1981; Syrett, 1981; Vergara et
al., 1998) or a competition of ammonium and nitrate uptake
mechanisms for energy resources, leading to the preferential uptake
of ammonium (Terry, 1982a; Terry, 1982b).
. Obviously, if there is ammonium the zooxanthelae and bacteria will use it preferentially as agreed earlier : not just zooxanthellae. Either bactreri8a or zooxanthelae will use all of the dissolved N whether it comes from ammonium or nitrate unitl the law of "the law of the minimum" applies in regard to other nutrients. As long as the ammonium is there it will be used preferentially limiting the need for nitrate by either zooxantheal or bacteria. However, by using the ammonium, nitrate creation via ammonia oxidation is reduced since there is less ammonia to transform to nitrate.
I disagree with the extropolation from the study to a point where sodium nitrate is noted as a preferred source to aspartate or other ammino acids. I don't think anything in the study or discussion supports that notion.
We could go back and forth with studies all day and confuse the issue if you like.
For example, here are two ,found in a few minutes, which present a different view on nitrate uptake by zooxanthellae than your view:
http://www.aoml.noaa.gov/general/lib/CREWS/Cleo/St. Croix/salt_river47.pdf
http://onlinelibrary.wiley.com/doi/10.1002/iroh.19740590102/abstract
Or keep it simple and agree to disagree. I do not agree that there is a reason to think ammonium limits zooxanthellae's uptake of nitrate anymore than it does denitrifying heterotrophic bacteria. Both will use available N to exhaustion unless another limiting nutrient comes into play. Therefore, the notion sodium nitrate is prefered to other sources like aspartate for a source of N assuming only bacteria will use it vs zooxanthellae doesn't work for me.
BTW, this thread concerning organic carbon may be of interest to some reading this thread:
http://www.reefcentral.com/forums/showthread.php?t=2134105&highlight=organic+carbon+dosing
The study cited in this post in the thread gives a good overview of denitrification processes including those performed by heterotrophic bacteria fed with orgnanic carbon:
This study gives an overview ,which was very helpful to me, of 3 major nitrogen pathways including: photoatuotrophic removal via photosynthetic activity: chemoautrotrophic activity by ammonia oxidizing bacteria producing nitrate and the activity of facultative heterotrophic bacteria supported with organic carbon. Though these pathways can occur in combination, the effects of increasing organic carbon content does likely reduce the level of activity by the other two.
The paper asserts the facultative heterotrophs take ammonia directly and may out compete the ammonia oxidizers as the former grow about 5 times as fast. It doesn't deal with amanox bacteria though but those obligate anaerobes are about 14 times slower in growth than the oxidizers ,conditions which make it unlikely ,IMO, that they play any significant role in a typical reef tank.
http://ag.arizona.edu/azaqua/ista/IS...%20Ebeling.pdf
Also ,Wikepedia notes most denitrifying bacteria are facultative, btw.
Nitrate reduction can take months when organic carbon dosing is started per many anecdotal reports . Maybe the bacteria take the N out at the front end of the process using the ammonia which cuts down the nitrate production to a point where they need to use a bit more energy to get at the N in the nitrate and/ or maybe anaerobic activity activity of the bacteria removes it eventually.
The study you cited which has as it's goals examination of phosphate uptake not nitrate uptake by bacteria or corals actually says:
. On the contrary, it is well-known, forexample, that nitrate uptake is generally inhibited in the presence of
ammonium (Badgley et al., 2006; Domotor and D’Elia, 1984; Grover
et al., 2003), either through a repression of the nitrate reductase (Berges
and Harrison, 1995; Guerrero et al., 1981; Syrett, 1981; Vergara et
al., 1998) or a competition of ammonium and nitrate uptake
mechanisms for energy resources, leading to the preferential uptake
of ammonium (Terry, 1982a; Terry, 1982b).
. Obviously, if there is ammonium the zooxanthelae and bacteria will use it preferentially as agreed earlier : not just zooxanthellae. Either bactreri8a or zooxanthelae will use all of the dissolved N whether it comes from ammonium or nitrate unitl the law of "the law of the minimum" applies in regard to other nutrients. As long as the ammonium is there it will be used preferentially limiting the need for nitrate by either zooxantheal or bacteria. However, by using the ammonium, nitrate creation via ammonia oxidation is reduced since there is less ammonia to transform to nitrate.
I disagree with the extropolation from the study to a point where sodium nitrate is noted as a preferred source to aspartate or other ammino acids. I don't think anything in the study or discussion supports that notion.
We could go back and forth with studies all day and confuse the issue if you like.
For example, here are two ,found in a few minutes, which present a different view on nitrate uptake by zooxanthellae than your view:
http://www.aoml.noaa.gov/general/lib/CREWS/Cleo/St. Croix/salt_river47.pdf
http://onlinelibrary.wiley.com/doi/10.1002/iroh.19740590102/abstract
Or keep it simple and agree to disagree. I do not agree that there is a reason to think ammonium limits zooxanthellae's uptake of nitrate anymore than it does denitrifying heterotrophic bacteria. Both will use available N to exhaustion unless another limiting nutrient comes into play. Therefore, the notion sodium nitrate is prefered to other sources like aspartate for a source of N assuming only bacteria will use it vs zooxanthellae doesn't work for me.
BTW, this thread concerning organic carbon may be of interest to some reading this thread:
http://www.reefcentral.com/forums/showthread.php?t=2134105&highlight=organic+carbon+dosing
The study cited in this post in the thread gives a good overview of denitrification processes including those performed by heterotrophic bacteria fed with orgnanic carbon:
This study gives an overview ,which was very helpful to me, of 3 major nitrogen pathways including: photoatuotrophic removal via photosynthetic activity: chemoautrotrophic activity by ammonia oxidizing bacteria producing nitrate and the activity of facultative heterotrophic bacteria supported with organic carbon. Though these pathways can occur in combination, the effects of increasing organic carbon content does likely reduce the level of activity by the other two.
The paper asserts the facultative heterotrophs take ammonia directly and may out compete the ammonia oxidizers as the former grow about 5 times as fast. It doesn't deal with amanox bacteria though but those obligate anaerobes are about 14 times slower in growth than the oxidizers ,conditions which make it unlikely ,IMO, that they play any significant role in a typical reef tank.
http://ag.arizona.edu/azaqua/ista/IS...%20Ebeling.pdf
Also ,Wikepedia notes most denitrifying bacteria are facultative, btw.
Nitrate reduction can take months when organic carbon dosing is started per many anecdotal reports . Maybe the bacteria take the N out at the front end of the process using the ammonia which cuts down the nitrate production to a point where they need to use a bit more energy to get at the N in the nitrate and/ or maybe anaerobic activity activity of the bacteria removes it eventually.
alexander_ktn
New member
Yes we can go back and forth or I could start yelling at the brick wall in front of me. Both will be about equally unpleasant and both will have the same effect.
oceanarium
New member
I have been using a nitrogen source for a number of years, mixing the dosing rates and testing the results within our 4 separate systems for a number of years. I can clearly see a NO3 consumption deficit in the way i manage my water with very positive results meeting this deficit with manual additions.
Observations are adding more NO3 allows us in being able to add more carbon source lowering PO4 further.
More importantly to me my NO3 can be so limited corals are suffering from the lack of nitrogen. With the addition I can clearly see increased growth and vitality in my observations this can be especially obvious with some species as chalice corals.
I can add significant amounts of NO3 to my systems 6ml / mixed at 100g CaNO3 / ltr per 1000ltrs added daily in two doses, yet testing results for NO3 can be as low as 0.002mg/ltr.
I generally aim to keep adding NO3 till the levels start to rise to no more than 0.03 this allows me to keep good colors in some of my more sensitive sps i have here, whilst supplementing the NO3 deficit.
I don't pretend to be any expert in chemistry, but have run commercial coral facility's one one type or another the past 20 years. The current facility running 5 years a dedicated coral farm of 4 separate systems some 20,000ltrs and 10,000 corals of all types, so i do get to do some considerable observations.
I have began using carbon and nitrate dosing as the principle form of PO4 and NO3 reduction in the current facility. I don't run any GFO or DSB water tests are usually <0.04 PO4 and <0.03 NO3.
To toss in a curly I also run a trickle tower on each system the past few years.
I will add my experience as well. I have been dosing nitrate for quite a while now. The purpose was not exclusively for phosphate control as I use carbon dosing for feeding filter feeders, but my corals would pale, in just a few days after dosing nitrate for the 1st time the colors came back, I was surprised how fast it was. So now I don't let it get that far and test nitrate every week. A little bit of color in the salifert test is my goal, no color and I add a little bit of sodium nitrate. This has been working well to prevent the fading colors I experienced.
Yes we can go back and forth or I could start yelling at the brick wall in front of me. Both will be about equally unpleasant and both will have the same effect.
That type of comment is not necessary or warranted.
It's the third time you have tended to attempt move this discussion toward a personal argument; it's not. I simply disagree that the following statement is supported by the arguments presented made so far:
So if one wants to add a nitrogen source that does not directly end up in the corals and rather feeds the bacteria, nitrate might be the better choice.
Disagreement doesn't have to be unpleasant or disrespectful.
That type of comment is not necessary or warranted.
It's the third time you have tended to attempt move this discussion toward a personal argument; it's not. I simply disagree that the following statement is supported by the arguments presented made so far:
So if one wants to add a nitrogen source that does not directly end up in the corals and rather feeds the bacteria, nitrate might be the better choice.
Disagreement doesn't have to be unpleasant or disrespectful.
Pete, Hart,
Thankyou for the information.
I think nitrogen additions can be helpful . Nitrogen deficiencies are possible ,particualry when dosing organic carbon.. I kept my NO3 reading to a slight tinge of pink on the Salifert test; didn't observe the results you are getting with either aspartic acid or sodium nitrate. In my case discontinuing gfo and nitrate dosing and boosting organic C a little enhanced coral vibrancy particularly for the chalice corals. These tanks get a lot of food though. If I get to point with clear water on the test. I might dose a little again from time to time.
I think it's a matter of balance of the nutrient elements the animals need ; deficiencies in a specific nutrient will will vary from aquarium to aquarium.
Are either of you dosing other nutrients: iron, potassium, ammino acids,btw etc?
Thankyou for the information.
I think nitrogen additions can be helpful . Nitrogen deficiencies are possible ,particualry when dosing organic carbon.. I kept my NO3 reading to a slight tinge of pink on the Salifert test; didn't observe the results you are getting with either aspartic acid or sodium nitrate. In my case discontinuing gfo and nitrate dosing and boosting organic C a little enhanced coral vibrancy particularly for the chalice corals. These tanks get a lot of food though. If I get to point with clear water on the test. I might dose a little again from time to time.
I think it's a matter of balance of the nutrient elements the animals need ; deficiencies in a specific nutrient will will vary from aquarium to aquarium.
Are either of you dosing other nutrients: iron, potassium, ammino acids,btw etc?
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oceanarium
New member
I have at times fed quite heavily to achieve 'better results' in correcting the nitrate deficiency. Though extra feeding was working with the corals it also had other consequences in the form of to much could lead to cyno or algae. It also resulted in increasing PO4 leading to further exasperating the situation with more carbon needed.
Now i have found a balance that works well for me, nitrate dosing twice daily alongside the carbon dose with the extra coral feeding reduced from daily to twice weekly amino's have remained a daily dose to help compensate for nitrate deficiency.
I add potassium and have experimented with iron, though always a bit careful with iron my water is not polished as well as it might be and careful not to spur any algae out breaks.
I agree with Hart, its quite obvious from the coral colors when they are not getting enough nitrate and the response can be within days once corrected.
Chalice are my indicator coral if I can see pale or through the flesh I know i am not providing enough nitrate.
When I set up the idea was to use clams sponges etc to help create a more natural type balance, these filter feeders reducing the bacteria load from the carbon dose. So skimmers are under size for the water volume. Sponge and clam growth is phenomenal, but possibly this is causing the nitrogen deficit?
Now i have found a balance that works well for me, nitrate dosing twice daily alongside the carbon dose with the extra coral feeding reduced from daily to twice weekly amino's have remained a daily dose to help compensate for nitrate deficiency.
I add potassium and have experimented with iron, though always a bit careful with iron my water is not polished as well as it might be and careful not to spur any algae out breaks.
I agree with Hart, its quite obvious from the coral colors when they are not getting enough nitrate and the response can be within days once corrected.
Chalice are my indicator coral if I can see pale or through the flesh I know i am not providing enough nitrate.
When I set up the idea was to use clams sponges etc to help create a more natural type balance, these filter feeders reducing the bacteria load from the carbon dose. So skimmers are under size for the water volume. Sponge and clam growth is phenomenal, but possibly this is causing the nitrogen deficit?
I also have prolific sponge growth with organic carbon dosing. They seem to benefit from the bacteria; zoanthids also do better .maybe from sponge cells , maybe from the bacteria . The sponges take up inorganic nutreints and convert them to organics;so, they might have a significant impact on dissolved nitrogen levels.
I feed a lot since I keep a lot of fish and corals. . Food adds a variety of nutrients including phosphate . If PO4 is an issue in a particular tank ; food increases it. Some find they need a little more phosphate ;most are focused on reducing it .
I feed a lot since I keep a lot of fish and corals. . Food adds a variety of nutrients including phosphate . If PO4 is an issue in a particular tank ; food increases it. Some find they need a little more phosphate ;most are focused on reducing it .
Guys thanks for the post and discussion. My order of KNO3 is on the way and I'd consider giving it a try, starting with making some NO3 standards to first test my salifert NO3 kit, which has always given me 0 reading (or far less than its 0.2ppm limit, I couldn't see any hint of color even looking from the side of the vial). I'd like to see what known concentration of KNO3 will give my salifert a slightest hint of pink or any color, or have you guys done this, home made standards against salifert NO3 kits?
Question for you regarding "bio indicator" for trace NO3, if salifert can't really help on this, at what level will NO3 become limiting for micro algae, and what level for macro? The green / brown powder-ish film on my glass sometimes takes a week to develop, but sometimes visible on the same day I wipe the glass, I have some macro in the sump most of the time not quite growing merely surviving but sometimes suddenly double in 2 weeks.
Asking because my PO4 has always been high, very high, and I'm dosing organic carbon at double the usual recommendation (75ml vinegar equivalent in 50G), these conditions (high PO4 and high carbon dosing) are quite consistent, the only changing condition is probably my NO3 which salifert kit always tells me to be 0, but I know it shouldn't be.
Question for you regarding "bio indicator" for trace NO3, if salifert can't really help on this, at what level will NO3 become limiting for micro algae, and what level for macro? The green / brown powder-ish film on my glass sometimes takes a week to develop, but sometimes visible on the same day I wipe the glass, I have some macro in the sump most of the time not quite growing merely surviving but sometimes suddenly double in 2 weeks.
Asking because my PO4 has always been high, very high, and I'm dosing organic carbon at double the usual recommendation (75ml vinegar equivalent in 50G), these conditions (high PO4 and high carbon dosing) are quite consistent, the only changing condition is probably my NO3 which salifert kit always tells me to be 0, but I know it shouldn't be.
oceanarium
New member
I use a photometer and low range reagent to test, the test kits always read clear.
Spslvr
New member
http://scholar.google.com.au/schola...a=X&ei=xetjVZjTCojh8gWI4oPABg&ved=0CAgQgQMwAA
I found the first article quite usefull, as i have stated in other threads, specific plant fertilisers are awsome and cover all spectrums needed. What i find interesting is the rate of which scleractinians uptake ammonium we all go on about nitrate and phosphate but ammonium is very much ignored yet just as important....
Its almost as if these are another big three... Cal,Alk, Mag... and nitrogen, phosphorus, ammonium.
Apologies tmz i just realised you already posted this article....
I found the first article quite usefull, as i have stated in other threads, specific plant fertilisers are awsome and cover all spectrums needed. What i find interesting is the rate of which scleractinians uptake ammonium we all go on about nitrate and phosphate but ammonium is very much ignored yet just as important....
Its almost as if these are another big three... Cal,Alk, Mag... and nitrogen, phosphorus, ammonium.
Apologies tmz i just realised you already posted this article....
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