Hi guys, new poster long time in the hobby. I am trying to find information on what types of carbon sources may be more beneficial to the consumption of phosphates over nitrates. For instance lets say your tank has near zero nitrates, (meaning undetectable levels), but has po4 at .15-.20ppm. Dosing vodka or vinegar in my experience seems to do little to reduce phosphates as compared to the drastic reduction in nitrates most achieve. I am well aware of gfo and other chemical means to accomplish this but would like to see if it is possible biologically. Again, this is not a noob question, I am well aware of how the cycle operates, I am just trying to see if anyone has experience in using different carbon sources to target specific areas. Thanks
Which carbon source for po4 reduction?
- Thread starter RJL55
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HighlandReefer
Team RC
Phosphate is used much slower than nitrate by the bacteria & other organisms. The Redfield ratio provides the approximate average rate & is the molecular ratio of carbon, nitrogen and phosphorus in plankton. The stoichiometric ratio is C:N
= 106:16:1. From this on average for every 16 parts of nitrogen used, the organisms will only use around 1 part phosphorous.
Some bacteria will use a higher percentage of phosphate vs other forms of phosphorous.
So to try and answer you question, the source of carbon to stimulate bacterial growth would not be as important as perhaps the species of bacteria present in your system. Regardless of the bacteria present, phosphate will still be used much slower than nitrate. Hence the recommendation to use GFO when nitrates are low and phosphate is high.
= 106:16:1. From this on average for every 16 parts of nitrogen used, the organisms will only use around 1 part phosphorous. Some bacteria will use a higher percentage of phosphate vs other forms of phosphorous.
So to try and answer you question, the source of carbon to stimulate bacterial growth would not be as important as perhaps the species of bacteria present in your system. Regardless of the bacteria present, phosphate will still be used much slower than nitrate. Hence the recommendation to use GFO when nitrates are low and phosphate is high.
HighlandReefer
Team RC
You're welcome.
I'd think the best for PO4 reduction would be the one that drives the most cyano growth. This is because cyano can continue to grow once nitrate has been delpeated via nitrogen fixation.
I'm not sure if tmz was serious or not about liking cyano, in the vinegar thread. However, while I sure don't want it in my display, I do actually wonder if it would be worthwhile to encourage cyano in our sumps or maybe biopellet reactors even. I think this could be done by tweaking the lighting. As long as they cyano in the sump or biopellet reactor is out competing the cyano in the display for nutrients, it should stay in the sump.
Of course it's probably safer to just run GFO :lol:
I'm not sure if tmz was serious or not about liking cyano, in the vinegar thread. However, while I sure don't want it in my display, I do actually wonder if it would be worthwhile to encourage cyano in our sumps or maybe biopellet reactors even. I think this could be done by tweaking the lighting. As long as they cyano in the sump or biopellet reactor is out competing the cyano in the display for nutrients, it should stay in the sump.
Of course it's probably safer to just run GFO :lol:
I think using a phosphate binder when NO3 is low is a good course.
How variable strains of bacteria interact with various carbon sources in variable tank conditions is idiosyncratic and much is unknown.
I don't know of any reliable information on one type of organic carbon being more effective than another in encouraging bacteria that would use relatively higher proportions of phosphorous vs carbon and nitrogen.
How variable strains of bacteria interact with various carbon sources in variable tank conditions is idiosyncratic and much is unknown.
I don't know of any reliable information on one type of organic carbon being more effective than another in encouraging bacteria that would use relatively higher proportions of phosphorous vs carbon and nitrogen.
Just an update: I have been dosing Brightwell Florin Gro for about 3 weeks now, (For those not familiar it is a sodium nitrate product). While I did get a little cyano, both green and red on my sand bed, they have subsided. My Po4 has gone from roughly .20 to .08 and is still droping daily with no water changes and no gfo since I started this experiment. It took about a week to see any results, started at 5 drops per day, now at 15, maybe I will go to 20. Just a reminder, my tank had zero and I mean 0 detectable nitrates to start with, now its about .5, so this could be a large factor in my positive results. I figure I'll dose for another 2 weeks and see what happens. DISCLAIMER: I am just having a little fun with this and posting some preliminary results. I do not want to debate the science behind it, IT WORKS FOR ME, BUT MAY NOT WORK FOR YOU, its that simple. Thanks, Rich
I too use a phosphate binder with organic carbon dosing.
IMO, organic carbon dosing is not a balanced export method, since some of it may be used anaerobically where nitrate is used in place of O2. So such methods may drop nitrate more than would be expected from the phosphate drop, potentially requiring another unbalanced method that uses more phosphate, like a binder.
That said, adding a nitrogen source (nitrate, amino acids, etc) is also a solution to this issue.
IMO, organic carbon dosing is not a balanced export method, since some of it may be used anaerobically where nitrate is used in place of O2. So such methods may drop nitrate more than would be expected from the phosphate drop, potentially requiring another unbalanced method that uses more phosphate, like a binder.
That said, adding a nitrogen source (nitrate, amino acids, etc) is also a solution to this issue.
sahin
Ultimate Reefer
Interested in this thread as I have the same issue:
Before I started to dose vinegar, I had about 20ppm of nitrates...weeks later and my nitrates are unreadable. I have since started to use GFO to take up the phosphates. Ordered a Hanna Phosphorus meter today, so hopefully I can fine tune the rowaphos reactor.
Before I started to dose vinegar, I had about 20ppm of nitrates...weeks later and my nitrates are unreadable. I have since started to use GFO to take up the phosphates. Ordered a Hanna Phosphorus meter today, so hopefully I can fine tune the rowaphos reactor.
aculross
Member
I too use a phosphate binder with organic carbon dosing.
IMO, organic carbon dosing is not a balanced export method, since some of it may be used anaerobically where nitrate is used in place of O2. So such methods may drop nitrate more than would be expected from the phosphate drop, potentially requiring another unbalanced method that uses more phosphate, like a binder.
That said, adding a nitrogen source (nitrate, amino acids, etc) is also a solution to this issue.
Could someone explain a bit more about this for me? I have a 120 that I started using WM biopellets on 1/1/11 - Nitrates have gone from 70 to rock-solid 0. I still have a phosphate issue (.08 on a hanna checker) and I'm dosing some BrightWell Phosphate product (lanthium cloride ?) to reduce phosphates. Is what is mentioned above a better alternative?
The lanthanum will provide a similar effect as a binder as I suggested, yes.
aculross
Member
The lanthanum will provide a similar effect as a binder as I suggested, yes.
I was under the impression that you were not overjoyed with lanthanum. You mentioned that you do use a binder - is it lanthanum or something else?
sahin
Ultimate Reefer
I think Randy uses GFO.
The issue with Lanthan is that you need some form of mechanical filtration - ie very very fine filter floss material to get the stuff out of the water. Otherwise it is reported to stay in the water and can cause gill irritation for fishes.
I think without some nitrates present corals will lose colour and become pale. And you can still have phosphate present at high levels in the tank. Hence why alot of poeple who dose carbon end up with pale corals. It happened to me in my last tank. I finally got phosphates down to reasonable levels via the use of GFO and it seems thats what I am having to do now.
Its frustrating because carbon dosing is very effective at reducing nitrates, but due to the ratio of uptake of nitrate to phosphate, the damn phosphate still remains an issue.
The other way is to dose some form of nitrates.
I'm going to stick to GFO and may dose vinegar and and again.
The issue with Lanthan is that you need some form of mechanical filtration - ie very very fine filter floss material to get the stuff out of the water. Otherwise it is reported to stay in the water and can cause gill irritation for fishes.
I think without some nitrates present corals will lose colour and become pale. And you can still have phosphate present at high levels in the tank. Hence why alot of poeple who dose carbon end up with pale corals. It happened to me in my last tank. I finally got phosphates down to reasonable levels via the use of GFO and it seems thats what I am having to do now.
Its frustrating because carbon dosing is very effective at reducing nitrates, but due to the ratio of uptake of nitrate to phosphate, the damn phosphate still remains an issue.
The other way is to dose some form of nitrates.
I'm going to stick to GFO and may dose vinegar and and again.
At the moment I'm using up some old (15 year old) X-phosphate, but I just bought some pelletized GFO from BRS.
Cecil, quick specs: 75g mixed reef with approx. 70g total water volume, SWC160 skimmer, 4 bulb t5, Profilux doser, mp20 and mp10 for circulation. Daily dosing consists of
10ml ESV 2-part, 4ml Brightwell Bio-Fuel, 15 drops Florin-Gro, and .5ml Mb7. In addition my make-up water is buffered with ESV liquid carbonate approx. 7ml per day. Water changes 10g, are done every 2 weeks with RO and ESV salt mix. Please note I have not done a water change for a few weeks (testing purposes), but plan on doing so this weekend. Rich
eli,
Actually, the ratio of N to P depleted when organic carbon dosing is likely much greater than 16 to 1. as Randy alluded to earlier.
Different strains of bacteria may have variable ratios ;the 106C:16N:1P does,however, give a good general view for discussion. The 16 approximately accounts for the N the bacteria consume along with 1 part of P and 106 parts of C; it does not account for the N not consumed but depleted as N2( nitrogen gas) from anaerobic bacterial activity.
FWIW,I still use gfo but much less ( less than a third ) than before carbon dosing to maintain low PO4 levels in a well fed system.
When I feed ,the food is typically adding N and P in the approximate 16 to 1 ratio too. So if your goal is to balance import and export of these nutrients organic carbon dosing may not do it all for P export but can come very close, ime.
M2,
I like cyanobacteria because I think the way it makes nitrogen gas(N2)likely formed in a star available for life is fascinating. I don't like it in my tanks. A little in a fuge doesn't bother me too much but even there I prefer macroalgaes.
I don't really know if the cyano strains in reef tanks would bother to form the anoxic structures( heterocysts) and the nitrogenase enzyme needed to break the N2 bond enabling nitrogen fixation but I suppose some strains in our tanks could if need be.
Actually, the ratio of N to P depleted when organic carbon dosing is likely much greater than 16 to 1. as Randy alluded to earlier.
Different strains of bacteria may have variable ratios ;the 106C:16N:1P does,however, give a good general view for discussion. The 16 approximately accounts for the N the bacteria consume along with 1 part of P and 106 parts of C; it does not account for the N not consumed but depleted as N2( nitrogen gas) from anaerobic bacterial activity.
FWIW,I still use gfo but much less ( less than a third ) than before carbon dosing to maintain low PO4 levels in a well fed system.
When I feed ,the food is typically adding N and P in the approximate 16 to 1 ratio too. So if your goal is to balance import and export of these nutrients organic carbon dosing may not do it all for P export but can come very close, ime.
M2,
I like cyanobacteria because I think the way it makes nitrogen gas(N2)likely formed in a star available for life is fascinating. I don't like it in my tanks. A little in a fuge doesn't bother me too much but even there I prefer macroalgaes.
I don't really know if the cyano strains in reef tanks would bother to form the anoxic structures( heterocysts) and the nitrogenase enzyme needed to break the N2 bond enabling nitrogen fixation but I suppose some strains in our tanks could if need be.
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