"Austin's Clear Ammonia" purchased from Tractor Supply at $4 per gallon.
Active ingrediant is ammonium hydroxide.
Patrick
Dosing Nitrate to reduce Phosphate
- Thread starter 2hands
- Start date
"Austin's Clear Ammonia" purchased from Tractor Supply at $4 per gallon.
Active ingrediant is ammonium hydroxide.
Patrick
Aquarist007
New member
Quote:
<table border="0" width="100%" cellpadding="5" cellspacing="0"> <tbody><tr> <td class="alt2" style="border:1px inset"> Originally Posted by tmz
I disagree with the last sentence. Depending on the ration of N to P in the bacteria removed, it is very relevant to the discussion of the thread.
Skimmers remove organics including bacteria. Individual orgniac compounds and organisms have variable Nratios. En masse ,why would the content of skimmate have a different ratio of N and P than the tank? Seems it wouldn't; I don't think GAC would efffect the ratio either, overall. Not exporting organics likely wouldn't effect the ratio either;just the overall volume.
</td> </tr> </tbody></table>
If the individual organisms and organics have different ratios then the tank and are concentrated in the skimmate then it is it not conceivable that the skimmate could have a different ratio to the tank?
Scott, I'm late in answering ; been distracted with family health issues.
Anything is possible but there isn't any plausible reason I can imagine to think the C:N
Organisms have protein which is attracted to the air water interface ,that is why a skimmer is called a protein skimmer,btw. .
Overall ratios in skimmate are very likely to be similar in C,N,P composition as the source tank water ,IMO.
A little organic chemistry regarding solubility shows why I think so.
Molecules in water range from hydrophyllic to hydrophobic:
Those that love water,(hydrophylic) and are bound to it (solubles like salt,sugar, ethyl alchohol, glycol ammonia ammino acids ,many inorganic compounds ). These are not attracted to the air water interface at the surface of the water in a tank or the the air water interface in a bubble of air in a skimmer's water column.
Hydrophobic molecules,those that are repelled by water( fats, oils, gasoline ,etc) are squeezed out of solution by the attraction water molecules have for one another and go to the air water interface forming surface films.
Like most distinctions the differences between hyrophobic molecules an hydrophylic molecules fall on a continuum .
In the middle are amphipatic molecules which have both hyrdorphylic and hydrophobic components ;proteins and most organic molecules in a reef tank fall into the amphipathic category.
The amphipatic molecules are attracted the air water interface.
" ...In actual practice, most organic molecules found in a marine tank will be amphipathic, with the bulk of the remainder being hydrophilic. There will be relatively few purely hydrophobic molecules (e.g., fat) in the tank. Most very hydrophilic molecules will not be removed by a skimmer, so understanding how amphipathic molecules react in a skimmer is the key to understanding how a skimmer works. One reason that skimmers are often referred to as protein skimmers is that most proteins are amphipathic. They often have an interior made from hydrophobic amino acids, and an exterior made of hydrophilic ones. When dissolved in water, only the hydrophilic exterior portions contact the water molecules. When placed in contact with an air interface (or something that is hydrophobic) the proteins will alter their shape, and present the hydrophobic portion to the interface. In this fashion they are readily attracted to an air/water interface..."
The above is per an article by Randy H. Farely
http://web.archive.org/web/20010309054900/http://home.mweb.co.za/jv/jv79/reef/skimmers2.html
So why would a skimmer select amphipathic molecules with C:N
Missed you Tom
Hope all okay with you and your family
Thanks for the detailed and very understandable post...much appreciated
herring_fish
Crazy Designer
Ok common, off the shelf ammonia. Thanks
My tank is down right now as I am outfitting the new tank. I have my rock in a trash container with just a bubbler aerating it. I think that I might get the scrubber working on the bucket. That way, if I have left over phosphate in the rock, I can get the algae growing full blast and draw it off while I wait.
Since the rock isn't illuminated much, I can play around without hurting anything. I MIGHT even get some calcareous algae growing in the bucket. Water canges are easy with such a small volume.
My tank is down right now as I am outfitting the new tank. I have my rock in a trash container with just a bubbler aerating it. I think that I might get the scrubber working on the bucket. That way, if I have left over phosphate in the rock, I can get the algae growing full blast and draw it off while I wait.
Since the rock isn't illuminated much, I can play around without hurting anything. I MIGHT even get some calcareous algae growing in the bucket. Water canges are easy with such a small volume.
I use the ACE brand ammonia. Janitorial strength.
You just don't want any sent or surfactants in it. Give the bottle a shake and if it foams and stays foamy. You don't want it.
slavetonet
New member
Continuing my experiment......
Day 1 ) Reading of 5ppm Nitrate, Phosphate 0.2ppm - No visual sign of diatoms and algae on rocks looking pale for reference.
Day 2 ) Initial reading 2.5ppm Nitrate - re-dosing 10ml to bring it up to + 5ppm Nitrate, Phosphate 0.1ppm - Diatoms starting to appear all over my sand substrate and algae on rocks looks like greening up.
Day 3 ) Nitrate reading 2.5ppm - Diatoms took off and is all over my sand substrate. Phosphate about the same 0.1 ppm and algae on rock s turn dark brown. I think I have brown hair algae. Will take a photo for CP to id.
Day 4 ) Nitrate reading undetectable - Diatoms disappear on sand substrate. Phosphate about less than >0.1ppm - RedSea test kit sux.. can't read lower. I will order a Hanna Checker + regent.
Re dose again 5ml KNO3 this time.
Day 5 ) Nitrate reading 2.5ppm - Diatoms is back again. Phosphate is less than >0.1ppm almost yellow reading with test kit. Brown Algae continue to be healthy brown, but not really growing to my eyes.
Day 6 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate less than > 0.1ppm. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour. Note -I have no fish in the aquarium to eat algae and minimum clean up crews to affect the algae.
Day 7 ) Same as Day 6 results, waiting for my Hanna Checker.
Day 1 ) Reading of 5ppm Nitrate, Phosphate 0.2ppm - No visual sign of diatoms and algae on rocks looking pale for reference.
Day 2 ) Initial reading 2.5ppm Nitrate - re-dosing 10ml to bring it up to + 5ppm Nitrate, Phosphate 0.1ppm - Diatoms starting to appear all over my sand substrate and algae on rocks looks like greening up.
Day 3 ) Nitrate reading 2.5ppm - Diatoms took off and is all over my sand substrate. Phosphate about the same 0.1 ppm and algae on rock s turn dark brown. I think I have brown hair algae. Will take a photo for CP to id.
Day 4 ) Nitrate reading undetectable - Diatoms disappear on sand substrate. Phosphate about less than >0.1ppm - RedSea test kit sux.. can't read lower. I will order a Hanna Checker + regent.
Re dose again 5ml KNO3 this time.
Day 5 ) Nitrate reading 2.5ppm - Diatoms is back again. Phosphate is less than >0.1ppm almost yellow reading with test kit. Brown Algae continue to be healthy brown, but not really growing to my eyes.
Day 6 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate less than > 0.1ppm. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour. Note -I have no fish in the aquarium to eat algae and minimum clean up crews to affect the algae.
Day 7 ) Same as Day 6 results, waiting for my Hanna Checker.
slavetonet
New member
Continuing my experiment......
Day 1 ) Reading of 5ppm Nitrate, Phosphate 0.2ppm - No visual sign of diatoms and algae on rocks looking pale for reference.
Day 2 ) Initial reading 2.5ppm Nitrate - re-dosing 10ml to bring it up to + 5ppm Nitrate, Phosphate 0.1ppm - Diatoms starting to appear all over my sand substrate and algae on rocks looks like greening up.
Day 3 ) Nitrate reading 2.5ppm - Diatoms took off and is all over my sand substrate. Phosphate about the same 0.1 ppm and algae on rock s turn dark brown. I think I have brown hair algae. Will take a photo for CP to id.
Day 4 ) Nitrate reading undetectable - Diatoms disappear on sand substrate. Phosphate about less than >0.1ppm - RedSea test kit sux.. can't read lower. I will order a Hanna Checker + regent.
Re dose again 5ml KNO3 this time.
Day 5 ) Nitrate reading 2.5ppm - Diatoms is back again. Phosphate is less than >0.1ppm almost yellow reading with test kit. Brown Algae continue to be healthy brown, but not really growing to my eyes.
Day 6 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate less than > 0.1ppm. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour. Note -I have no fish in the aquarium to eat algae and minimum clean up crews to affect the algae.
Day 7 ) Same as Day 6 results, waiting for my Hanna Checker.
Day 8 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate is 0.03ppm with Hanna checker. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour.
The theory of dosing nitrate + carbon source + phosphate as food for bacteria in the environment when N limited = Success! Redfield ratio works great.
I am not sure if it is 16:1 or 20:1 but I am very happy I have experimented on this and I thank members of RC to trying it out.
Next few days I am going to see if I keep dosing nitrate at 5ml every second day. Will my phosphate hit 0.00 or my nitrate starts to rise due to no phosphate to feed on.
Algae in theory should die off or turn white if that was the case.
Day 1 ) Reading of 5ppm Nitrate, Phosphate 0.2ppm - No visual sign of diatoms and algae on rocks looking pale for reference.
Day 2 ) Initial reading 2.5ppm Nitrate - re-dosing 10ml to bring it up to + 5ppm Nitrate, Phosphate 0.1ppm - Diatoms starting to appear all over my sand substrate and algae on rocks looks like greening up.
Day 3 ) Nitrate reading 2.5ppm - Diatoms took off and is all over my sand substrate. Phosphate about the same 0.1 ppm and algae on rock s turn dark brown. I think I have brown hair algae. Will take a photo for CP to id.
Day 4 ) Nitrate reading undetectable - Diatoms disappear on sand substrate. Phosphate about less than >0.1ppm - RedSea test kit sux.. can't read lower. I will order a Hanna Checker + regent.
Re dose again 5ml KNO3 this time.
Day 5 ) Nitrate reading 2.5ppm - Diatoms is back again. Phosphate is less than >0.1ppm almost yellow reading with test kit. Brown Algae continue to be healthy brown, but not really growing to my eyes.
Day 6 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate less than > 0.1ppm. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour. Note -I have no fish in the aquarium to eat algae and minimum clean up crews to affect the algae.
Day 7 ) Same as Day 6 results, waiting for my Hanna Checker.
Day 8 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate is 0.03ppm with Hanna checker. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour.
The theory of dosing nitrate + carbon source + phosphate as food for bacteria in the environment when N limited = Success! Redfield ratio works great.
I am not sure if it is 16:1 or 20:1 but I am very happy I have experimented on this and I thank members of RC to trying it out.
Next few days I am going to see if I keep dosing nitrate at 5ml every second day. Will my phosphate hit 0.00 or my nitrate starts to rise due to no phosphate to feed on.
Algae in theory should die off or turn white if that was the case.
I've been off the thread for a while . Glad to see more anecdotal accounts of NO3 dosing vs more arcane tangential discussion on nutrients which drifted away from the central point of the thread.
Nice detail in your report slavetonet.
Unfortunately, There are ,however, a few tangential points which were introduced earlier were introduceed that need a little iteration and clarification , IMO, if you are more interested in the anecdotal accounts which are more interesting to me anyway just skip this:
First, skimming:
It's a useful tool ;not a necessity for every tank. It is not unnatural, foam fractionation occurs in the sea.
I use heavy skimming on my main displays but run a couple of other tanks skimmerless where mostly leathers ,mushrooms octorals and gorgonia do very well.
Some points of clarification on what skimming does may be helpful :
I am interested in any scientific study that documents the amount of oxygen added due to skimming. Considering that surface tension promotes nutrient export at the bubble air interface, imo, this same surface tension interfers with water/air gas exchange. For my money the water/air interface in the display tank is a much bigger player in gas exchange.
Patrick
That's not correct,IMO. Organics with mixed polarity(amphpathic molecules, which are most of them ,are attracted to the air water interface ,one side pulling toward the water and the other away from .When the bubble rises to the surface it pops releasing the the amphipathic molecules stuck in the air water interface.
I already noted the Borneman "Right to Breathe" articles in which he measure oxygen levels with and without skimmers in use.
There are also references to significant gas exchange by skimmers and it's benfits in The Reef Aquirum 3 by Sprung and Delbeek,when one reads the whole story :
pg 308....protein skimmers also serve another very useful task, The injection of air into the skimmer helps to bring the seawater into equilibrium with carbon dioxide in the atmosphere by expelling excess carbon dioxide from the water ;resulting in more stable pH.......Gas exchange is also improved in the aquarium since the skimmer removes surfacants form the water which would otherwise coat the aquarium water surface and slow gas exchange ....."
and two articles on protein skimming by Randy Farely.
Then if all that isn't enough, there is the obvious geometry in terms of the greater surface area in a sphere vs a flat surface and the fact that bubbles occupy 6 inches or more of water depth vs a single layer of surface water in a tank.
Further, adding low CO2 air to skimmer intakes raises pH in an aquarium . This has been tested hundreds of times by aquaist by running airlines to skimmer air intakes or using CO2 scrubbers even in the presence of rippling surface and in some cases trickle down filtration. None of those fresh air approaches would work without substantial gas exchange.
Rippled water trumps air bubbles Patrick
I say:
"Rippled surface water increases water surface volume exponentially ,bubbles even more so."
Patrick , pay attention to the coma,there is no intent to exagerrate as you accused me .
.... Conveiniently, air bubbles provide an excellant air-water interface for surfactants to adhere."
Now, let us focus on "surfactants to adhere". This would be scum or skimmate. Be assured that this scum does not promote good gas exchange. ...
Patrick
The amphipatic molicules form a monolayer which may be permeable to gas exchange . The air itself in the bubbles enters the water column in the skimmer without any organic film and dwells there. It is free of any adherning orgnanics for a portion of that time so gas exchange is unimpeded by any surfacants till near the end of the life of the bubble .
Nice detail in your report slavetonet.
Unfortunately, There are ,however, a few tangential points which were introduced earlier were introduceed that need a little iteration and clarification , IMO, if you are more interested in the anecdotal accounts which are more interesting to me anyway just skip this:
First, skimming:
It's a useful tool ;not a necessity for every tank. It is not unnatural, foam fractionation occurs in the sea.
I use heavy skimming on my main displays but run a couple of other tanks skimmerless where mostly leathers ,mushrooms octorals and gorgonia do very well.
Some points of clarification on what skimming does may be helpful :
I am interested in any scientific study that documents the amount of oxygen added due to skimming. Considering that surface tension promotes nutrient export at the bubble air interface, imo, this same surface tension interfers with water/air gas exchange. For my money the water/air interface in the display tank is a much bigger player in gas exchange.
Patrick
That's not correct,IMO. Organics with mixed polarity(amphpathic molecules, which are most of them ,are attracted to the air water interface ,one side pulling toward the water and the other away from .When the bubble rises to the surface it pops releasing the the amphipathic molecules stuck in the air water interface.
I already noted the Borneman "Right to Breathe" articles in which he measure oxygen levels with and without skimmers in use.
There are also references to significant gas exchange by skimmers and it's benfits in The Reef Aquirum 3 by Sprung and Delbeek,when one reads the whole story :
pg 308....protein skimmers also serve another very useful task, The injection of air into the skimmer helps to bring the seawater into equilibrium with carbon dioxide in the atmosphere by expelling excess carbon dioxide from the water ;resulting in more stable pH.......Gas exchange is also improved in the aquarium since the skimmer removes surfacants form the water which would otherwise coat the aquarium water surface and slow gas exchange ....."
and two articles on protein skimming by Randy Farely.
Then if all that isn't enough, there is the obvious geometry in terms of the greater surface area in a sphere vs a flat surface and the fact that bubbles occupy 6 inches or more of water depth vs a single layer of surface water in a tank.
Further, adding low CO2 air to skimmer intakes raises pH in an aquarium . This has been tested hundreds of times by aquaist by running airlines to skimmer air intakes or using CO2 scrubbers even in the presence of rippling surface and in some cases trickle down filtration. None of those fresh air approaches would work without substantial gas exchange.
Rippled water trumps air bubbles Patrick
I say:
"Rippled surface water increases water surface volume exponentially ,bubbles even more so."
Patrick , pay attention to the coma,there is no intent to exagerrate as you accused me .
.... Conveiniently, air bubbles provide an excellant air-water interface for surfactants to adhere."
Now, let us focus on "surfactants to adhere". This would be scum or skimmate. Be assured that this scum does not promote good gas exchange. ...
Patrick
The amphipatic molicules form a monolayer which may be permeable to gas exchange . The air itself in the bubbles enters the water column in the skimmer without any organic film and dwells there. It is free of any adherning orgnanics for a portion of that time so gas exchange is unimpeded by any surfacants till near the end of the life of the bubble .
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Your welcome Scott. Thanks for your kind words.
I do view leaving out details and dismissing data as less than an exchange of ideas and more as you establishing your superiority on the subject matter.
Patrick
Missed that
I view those things that way but I haven't done any of that. Suffice to say I think you have been looking in a fun house mirror lately.
Patrick
Missed that
I view those things that way but I haven't done any of that. Suffice to say I think you have been looking in a fun house mirror lately.
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slavetonet
New member
Continuing my experiment......
Day 1 ) Reading of 5ppm Nitrate, Phosphate 0.2ppm - No visual sign of diatoms and algae on rocks looking pale for reference.
Day 2 ) Initial reading 2.5ppm Nitrate - re-dosing 10ml to bring it up to + 5ppm Nitrate, Phosphate 0.1ppm - Diatoms starting to appear all over my sand substrate and algae on rocks looks like greening up.
Day 3 ) Nitrate reading 2.5ppm - Diatoms took off and is all over my sand substrate. Phosphate about the same 0.1 ppm and algae on rock s turn dark brown. I think I have brown hair algae. Will take a photo for CP to id.
Day 4 ) Nitrate reading undetectable - Diatoms disappear on sand substrate. Phosphate about less than >0.1ppm - RedSea test kit sux.. can't read lower. I will order a Hanna Checker + regent.
Re dose again 5ml KNO3 this time.
Day 5 ) Nitrate reading 2.5ppm - Diatoms is back again. Phosphate is less than >0.1ppm almost yellow reading with test kit. Brown Algae continue to be healthy brown, but not really growing to my eyes.
Day 6 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate less than > 0.1ppm. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour. Note -I have no fish in the aquarium to eat algae and minimum clean up crews to affect the algae.
Day 7 ) Same as Day 6 results, waiting for my Hanna Checker.
Day 8 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate is 0.03ppm with Hanna checker. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour.
Day 9 ) Nitrate tested at 2.5ppm, Phosphate I didn't bother to test with Hanna Checker.
Diatoms have gone away in mass, but it is still traces on the sand bed. Looks like algae starting to die off a fair bit now, I am getting alot of algae floating in the water column with only wavemaker running and zero fish to eat algae. Under just the blue lighting, I can see the algae as redish colour. I have seen that before when I dose hydrogen peroxide to get rid of algae. It's the same sign that they are dying.
I have re-dose another 5ml of potassium nitrate - which should bring it up to about 5ppm Nitrate.
Day 10 ) I will not test anything tomorrow, but will report back on Day 11 to see if my nitrate reading have lower or stay at 5ppm. I will test phosphate on Day 11 with Hanna Checker.
If it is staying at 5ppm, I know I am Phosphate limited. WOW.. first time right. HAHA.
I have continue to feed my corals with Reef-Roid food daily while I am doing this experiment.
I have to thank all the people that have contributed here. If it wasn't for your experiment, I wouldn't have been able to fix it.
Day 1 ) Reading of 5ppm Nitrate, Phosphate 0.2ppm - No visual sign of diatoms and algae on rocks looking pale for reference.
Day 2 ) Initial reading 2.5ppm Nitrate - re-dosing 10ml to bring it up to + 5ppm Nitrate, Phosphate 0.1ppm - Diatoms starting to appear all over my sand substrate and algae on rocks looks like greening up.
Day 3 ) Nitrate reading 2.5ppm - Diatoms took off and is all over my sand substrate. Phosphate about the same 0.1 ppm and algae on rock s turn dark brown. I think I have brown hair algae. Will take a photo for CP to id.
Day 4 ) Nitrate reading undetectable - Diatoms disappear on sand substrate. Phosphate about less than >0.1ppm - RedSea test kit sux.. can't read lower. I will order a Hanna Checker + regent.
Re dose again 5ml KNO3 this time.
Day 5 ) Nitrate reading 2.5ppm - Diatoms is back again. Phosphate is less than >0.1ppm almost yellow reading with test kit. Brown Algae continue to be healthy brown, but not really growing to my eyes.
Day 6 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate less than > 0.1ppm. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour. Note -I have no fish in the aquarium to eat algae and minimum clean up crews to affect the algae.
Day 7 ) Same as Day 6 results, waiting for my Hanna Checker.
Day 8 ) re-dose 5ml KNO3 as Nitrate was 0ppm undetectable. Phosphate is 0.03ppm with Hanna checker. Diatoms still on sand bed, but have somewhat lessen. Looks like algae starting to thin out a bit, but still looking brown and green lush colour.
Day 9 ) Nitrate tested at 2.5ppm, Phosphate I didn't bother to test with Hanna Checker.
Diatoms have gone away in mass, but it is still traces on the sand bed. Looks like algae starting to die off a fair bit now, I am getting alot of algae floating in the water column with only wavemaker running and zero fish to eat algae. Under just the blue lighting, I can see the algae as redish colour. I have seen that before when I dose hydrogen peroxide to get rid of algae. It's the same sign that they are dying.
I have re-dose another 5ml of potassium nitrate - which should bring it up to about 5ppm Nitrate.
Day 10 ) I will not test anything tomorrow, but will report back on Day 11 to see if my nitrate reading have lower or stay at 5ppm. I will test phosphate on Day 11 with Hanna Checker.
If it is staying at 5ppm, I know I am Phosphate limited. WOW.. first time right. HAHA.
I have continue to feed my corals with Reef-Roid food daily while I am doing this experiment.
I have to thank all the people that have contributed here. If it wasn't for your experiment, I wouldn't have been able to fix it.
Originally Posted by Subsea
… When N is required I dose with ammonia.
Patrick
I've thought about doing that as it is suggested in a number of studies that organisms take ammonia preferentialy to nitrate, particulary denitrfying heterotropic bacteria .
However, my personal sense of caution proscribes dosing ammonia in significant amounts to a tank with living organisms like fish and inverts which may suffer from ammonia toxicity vs nitrate addtions.
Another difference between nitrate additions and ammonia additions is that ammonia degradation will deplete alkalinity ; the nitrate does not ;it adds bicarbonate alkainity.
For phototrophic nitrogen processing( eg. algae systems) these are the reactions:
Ammonia +CO2+phosphate +water + bicarbonate = algae + O2
Nitrate + Co2 + phosphate + water = algae + O2 + bicarbonate.
… When N is required I dose with ammonia.
Patrick
I've thought about doing that as it is suggested in a number of studies that organisms take ammonia preferentialy to nitrate, particulary denitrfying heterotropic bacteria .
However, my personal sense of caution proscribes dosing ammonia in significant amounts to a tank with living organisms like fish and inverts which may suffer from ammonia toxicity vs nitrate addtions.
Another difference between nitrate additions and ammonia additions is that ammonia degradation will deplete alkalinity ; the nitrate does not ;it adds bicarbonate alkainity.
For phototrophic nitrogen processing( eg. algae systems) these are the reactions:
Ammonia +CO2+phosphate +water + bicarbonate = algae + O2
Nitrate + Co2 + phosphate + water = algae + O2 + bicarbonate.
While I agree that adding nitrate and having it converted into tissue or N2 will add to alkalinity, I don't think it is correct that adding ammonia and incorporating it into tissues impacts alkalinity.
Think of it this way...
If you add ammonia and convert it into nitrate, you use up 1 unit of alkalinity per nitrogen atom:
NH3 + 2 O2 --> NO3-- + H+ + H2O
Then, when nitrate is used, you get it back exactly (1 unit of alkalinity per nitrogen atom):
138 CO2 + 16 NO3- + 154 H2O → organic + 175 O2 + 16 HCO3-
reefmutt
Active member
So, it could be said that nitrate additions will positively affect alkalinity while adding ammonia will not ultimately affect overall alkalinity?
I guess adding cano3 therefore has a dual positive effect by adding calcium as well as boosting alkalinity (probably, I assume to a rather small degree)
I guess adding cano3 therefore has a dual positive effect by adding calcium as well as boosting alkalinity (probably, I assume to a rather small degree)
Randy , Thanks.
Per your advice earlier in other discussions ,I know nitrate balances out any alkalinity taken as a result of ammonia oxidation.
I thought the nitrate only put it back via anaerobic activity as part of the conversion to N2.
If no nitrate is produced when ammonia is taken for assimilation of the N, I'm not clear on how or when the alk comes back.
I'm sure it does, absent any harvesting of organic matter which would take it's N with it, because you said so and I trust that.
I'm not clear on the process or timing in a tank as some N is incorporated in algae tissue at least until its degraded.
In an algae farming operation or an algal turf scrubber application it seems harvesting would limit alk put back . So ,suppose there is no harvesting and no degradation? How does the N move to nitrate, When it's assimilated into tissue is there a reaction affecting alkainity I'm unaware of?
Any help on nuances in the process would be appreciated. Do you think algae exudates play a significant a role in recycling N as NO3 from algae ?. Do algae toss off excess dissolved nitrogen or store it as some studies suggest?
Thanks again.
The reactions I cited come from this paper,fwiw:
http://ag.arizona.edu/azaqua/ista/ISTA7/RecircWorkshop/Workshop%20PP%20%20&%20Misc%20Papers%20Adobe%202006/7%20Biofiltration/Microbial%20Floc%20Systems/2006%20Roanoke%20-%20Understanding%20Trophic%20Systems%20%20Ebeling.pdf
Per your advice earlier in other discussions ,I know nitrate balances out any alkalinity taken as a result of ammonia oxidation.
I thought the nitrate only put it back via anaerobic activity as part of the conversion to N2.
If no nitrate is produced when ammonia is taken for assimilation of the N, I'm not clear on how or when the alk comes back.
I'm sure it does, absent any harvesting of organic matter which would take it's N with it, because you said so and I trust that.
I'm not clear on the process or timing in a tank as some N is incorporated in algae tissue at least until its degraded.
In an algae farming operation or an algal turf scrubber application it seems harvesting would limit alk put back . So ,suppose there is no harvesting and no degradation? How does the N move to nitrate, When it's assimilated into tissue is there a reaction affecting alkainity I'm unaware of?
Any help on nuances in the process would be appreciated. Do you think algae exudates play a significant a role in recycling N as NO3 from algae ?. Do algae toss off excess dissolved nitrogen or store it as some studies suggest?
Thanks again.
The reactions I cited come from this paper,fwiw:
http://ag.arizona.edu/azaqua/ista/ISTA7/RecircWorkshop/Workshop%20PP%20%20&%20Misc%20Papers%20Adobe%202006/7%20Biofiltration/Microbial%20Floc%20Systems/2006%20Roanoke%20-%20Understanding%20Trophic%20Systems%20%20Ebeling.pdf
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Aquarist007
New member
This article should be a required read for anyone interested in the role of bacteria in our tanks. I applaud you again Tom for offering up yet another great article.
I like the power point slides as reinforcement.. They really help someone like me who is ADDH
To put the article in perspective, what are the chemicals included in what we measure for alkalinity with our test kits? I was not aware that nitrates were, nor was there a relationship between alkalinity levels and nitrate levels
Yes, assuming the nitrate is consumed and not simply building up or being removed by water changes.
Calcium nitrate would be a balanced calcium and alkalinity additive.
It doesn't need to come back because it never went away. If the ammonia is converted to nitrate, you loose alkalinity, but converting ammonia into N2 or into most organic nitrogen compounds like proteins has no effect on alkalinity.
I'll have to read through that powerpoint later. I saw some things that I'm not sure I agree with, but I may be misunderstanding something.
Nitrate is not included in a total alkalinity titration.
Those that are include phosphate, borate, carbonate, hydroxide (both free and attached to magnesium), bicarbonate, silicate, and a subtraction of H+.
I see the issue (two actually) with the powerpoint article conclusion about ammonia.
Equation 1 seems to show that alkalinity is consumed, but that is not a correct conclusion:
16NH4+ + 92 CO2 + HPO42- + 92 H2O + 14 HCO3- → C106H263O110N16P + 106 O2
(1)
That is because they start with ammonium (NH4+), not ammonia (NH3), despite using the exact word "ammonia" in the slide.
If you start with ammonia, the same reaction now reads:
16NH3 + 92 CO2 + HPO42- + 92 H2O + 14 HCO3- + 16 H+ → C106H263O110N16P + 106 O2
So there is no net consumption of alkalinity.
The second issue I have is in the equation right after equation 5:
"The overall removal process can be described as (Ebeling et al., 2005):
NH4+ + 1.83 O2 + 1.97 HCO3- → 0.0244 C5H7O2N + 0.976 NO3- + 2.90 H2O + 1.86 CO2"
Not only does that "overall" process start with ammonium again, it leaves nitrate. Producing the nitrate consumed alkalinity as we know. If you process that nitrate into organics, the alkalinity comes back as we also agreed earlier). That accounts for the two equivalents of alkalinity consumed: one for ammonium issue and one for the nitrate produced.
So I agree that if you dose ammonium, such as ammonium chloride, you will deplete alkalinity by effectively adding a weak acid (the ammonium)
If you dose ammonia, such as ammonium hydroxide (ammonia solution) then alkalinity is not depleted when the nitrogen is converted into organics.
Equation 1 seems to show that alkalinity is consumed, but that is not a correct conclusion:
16NH4+ + 92 CO2 + HPO42- + 92 H2O + 14 HCO3- → C106H263O110N16P + 106 O2
(1)
That is because they start with ammonium (NH4+), not ammonia (NH3), despite using the exact word "ammonia" in the slide.
If you start with ammonia, the same reaction now reads:
16NH3 + 92 CO2 + HPO42- + 92 H2O + 14 HCO3- + 16 H+ → C106H263O110N16P + 106 O2
So there is no net consumption of alkalinity.
The second issue I have is in the equation right after equation 5:
"The overall removal process can be described as (Ebeling et al., 2005):
NH4+ + 1.83 O2 + 1.97 HCO3- → 0.0244 C5H7O2N + 0.976 NO3- + 2.90 H2O + 1.86 CO2"
Not only does that "overall" process start with ammonium again, it leaves nitrate. Producing the nitrate consumed alkalinity as we know. If you process that nitrate into organics, the alkalinity comes back as we also agreed earlier). That accounts for the two equivalents of alkalinity consumed: one for ammonium issue and one for the nitrate produced.
So I agree that if you dose ammonium, such as ammonium chloride, you will deplete alkalinity by effectively adding a weak acid (the ammonium)
If you dose ammonia, such as ammonium hydroxide (ammonia solution) then alkalinity is not depleted when the nitrogen is converted into organics.
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