Thales
Active member
I lost almost 95% of SPS in 2011. In December I added several SPS pieces/frags including a pale Red Dragon that has since colored up nicely.
Guess the Phosphate level
- Thread starter Thales
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I lost almost 95% of SPS in 2011. In December I added several SPS pieces/frags including a pale Red Dragon that has since colored up nicely.
Thales
Active member
I am using the Kalk/Vinegar as top off, but it is a fixed amount. There are float switches to a DI only reservoir as well.
I don't know if I buy the idea of high sensitivity of a reef tank to small doses of a carbon source...I spray down my loc line manifold a couple time a week with vinegar as well and it goes into the tank. Where does the highly sensitive idea come from?
Thales
Active member
Here are my results from AWT - quite a difference in the NO3 (regardless if they are testing nitrate-nitrogen or nitrate ion). Gotta see if I can get a retest at work soon.
01-27-2014 - Home Display - 2 of 6
Ammonia (NH3-4) Good 0 0.000 - 0.050 mg/L
Nitrite (NO2) Good 0.013 0.000 - 0.100 mg/L
Phosphate (PO4) High 1.34 0.000 - 0.250 mg/L
Nitrate (NO3) Good 13.4 0.000 - 25.000 mg/L
Silica (Sio2-3) High 1.5 0.000 - 0.500 mg/L
Potassium (K) Low 313 350.000 - 450.000 mg/L
Ionic Calcium (Ca) Good 152 100.000 - 300.000 mg/L
Boron (B) NA NA 3.000 - 6.000 mg/L
Molybdenum (Mo) High 0.3 0.000 - 0.120 mg/L
Strontium (Sr) Good 8.1 5.000 - 12.000 mg/L
Magnesium (Mg) Good 1188 1100.000 - 1400.000 mg/L
Iodine (I) Good 0.05 0.030 - 0.090 mg/L
Copper (Cu) Good 0.03 0.000 - 0.030 mg/L
Alkalinity (meq/L) Good 3.8 2.500 - 5.000 meq/L
Total Calcium (Ca) Good 440 350.000 - 450.000 mg/L
Iron (Fe) NA NA 0.000 - 0.010 mg/L
01-27-2014 - Home Display - 2 of 6
Ammonia (NH3-4) Good 0 0.000 - 0.050 mg/L
Nitrite (NO2) Good 0.013 0.000 - 0.100 mg/L
Phosphate (PO4) High 1.34 0.000 - 0.250 mg/L
Nitrate (NO3) Good 13.4 0.000 - 25.000 mg/L
Silica (Sio2-3) High 1.5 0.000 - 0.500 mg/L
Potassium (K) Low 313 350.000 - 450.000 mg/L
Ionic Calcium (Ca) Good 152 100.000 - 300.000 mg/L
Boron (B) NA NA 3.000 - 6.000 mg/L
Molybdenum (Mo) High 0.3 0.000 - 0.120 mg/L
Strontium (Sr) Good 8.1 5.000 - 12.000 mg/L
Magnesium (Mg) Good 1188 1100.000 - 1400.000 mg/L
Iodine (I) Good 0.05 0.030 - 0.090 mg/L
Copper (Cu) Good 0.03 0.000 - 0.030 mg/L
Alkalinity (meq/L) Good 3.8 2.500 - 5.000 meq/L
Total Calcium (Ca) Good 440 350.000 - 450.000 mg/L
Iron (Fe) NA NA 0.000 - 0.010 mg/L
Again, Rich, these numbers are suspiciously precise. What is the Method Uncertainty (read: Margin of Error) for each of the analysis methods employed? Almost certainly, they are significantly greater than the precision implied.
I'm 99.28237372381% certain that these numbers are more precise than the ability of the method to precisely quantify the amount of each substance.
Thales
Active member
Again, Rich, these numbers are suspiciously precise. What is the Method Uncertainty (read: Margin of Error) for each of the analysis methods employed? Almost certainly, they are significantly greater than the precision implied.
I'm 99.28237372381% certain that these numbers are more precise than the ability of the method to precisely quantify the amount of each substance.
Beats me Jim. I don't really look at the preciseness of the numbers in these or any test, but look instead for generalities. In other words, I agree with you. If our water quality people like the idea of doing math out to several decimals, I am not going to argue with them or try to get them to change. Too much work for too little pay off
Perhaps though, I will round up when posting them here.
I think my point goes directly to the general topic of your upcoming article, *if* I understand it correctly.
When it comes to doing analyses to quantify the measurement of some analyte in a sample, there are two factors that it is important to understand the real meaning of. They are the "accuracy" of the analysis method, and the "precision" of said method.
The "accuracy" describes the ability of the method to return a result that reflects the "true" result. In other words, how close is the result to the actual amount of the analyte in the sample?
The "precision" describes the ability of the method to return the same result over and over again with repeated tests of the same sample. In other words, how much, plus or minus, is the difference between repeated analyses of the same sample material with the test method?
This is commonly illustrated by the "target" model. Pretend the accuracy and precision of a test method were to be represented, metaphorically, as a set of several arrows shot at a target. A method that was accurate but not precise would be shown as a bunch of arrows loosely grouped such that the "average" of them would be centered on the target, but with wide spacing between the shots. A method that was precise but not accurate would be a tight group of shots, but somewhat away from the bullseye, e.g., high and to the left. A method that was both accurate and precise would be tightly grouped very near the bullseye. A method that was neither accurate nor precise would be all over the place.
It makes no sense, and is actually counterproductive, to pay any attention to numbers in analytical results that are more precise than the given method is able to deliver. If, for example, the method used to determine Total Calcium is only able to determine the result to a precision of +/- 5 PPM, then it is really meaningless to report 426.4 PPM. The only honest answer in this context is 425 PPM.
The "accuracy" may be affected by some kind of bias that causes the value returned to be skewed by some value "X", which may be either positive or negative. For example, a titration test may be biased by the degradation of the pH of the titrant over time by the effect of atmospheric CO2. That means that it took more of the titrant to reach the color change at the end point, which makes the test return a value higher than the "true" amount of the analyte being tested for.
If a method is sufficiently precise, then an inaccurate value, due to some consistent bias, can still be useful to determine changes over time, as Rich has previously said, if the change over time is the important thing to pay attention to. If, on the other hand, the absolute "true" value is required, then accuracy can be more important than precision (as long as the precision of the method is "fit for purpose").
When it comes to doing analyses to quantify the measurement of some analyte in a sample, there are two factors that it is important to understand the real meaning of. They are the "accuracy" of the analysis method, and the "precision" of said method.
The "accuracy" describes the ability of the method to return a result that reflects the "true" result. In other words, how close is the result to the actual amount of the analyte in the sample?
The "precision" describes the ability of the method to return the same result over and over again with repeated tests of the same sample. In other words, how much, plus or minus, is the difference between repeated analyses of the same sample material with the test method?
This is commonly illustrated by the "target" model. Pretend the accuracy and precision of a test method were to be represented, metaphorically, as a set of several arrows shot at a target. A method that was accurate but not precise would be shown as a bunch of arrows loosely grouped such that the "average" of them would be centered on the target, but with wide spacing between the shots. A method that was precise but not accurate would be a tight group of shots, but somewhat away from the bullseye, e.g., high and to the left. A method that was both accurate and precise would be tightly grouped very near the bullseye. A method that was neither accurate nor precise would be all over the place.
It makes no sense, and is actually counterproductive, to pay any attention to numbers in analytical results that are more precise than the given method is able to deliver. If, for example, the method used to determine Total Calcium is only able to determine the result to a precision of +/- 5 PPM, then it is really meaningless to report 426.4 PPM. The only honest answer in this context is 425 PPM.
The "accuracy" may be affected by some kind of bias that causes the value returned to be skewed by some value "X", which may be either positive or negative. For example, a titration test may be biased by the degradation of the pH of the titrant over time by the effect of atmospheric CO2. That means that it took more of the titrant to reach the color change at the end point, which makes the test return a value higher than the "true" amount of the analyte being tested for.
If a method is sufficiently precise, then an inaccurate value, due to some consistent bias, can still be useful to determine changes over time, as Rich has previously said, if the change over time is the important thing to pay attention to. If, on the other hand, the absolute "true" value is required, then accuracy can be more important than precision (as long as the precision of the method is "fit for purpose").
Sorry Jim, I know your intentions are good, but this is incorrect. If the test kit can resolve a tenth of a ppm, but has a reproducibility at one standard deviation of plus or minus 5.0 ppm, and the worker obtains a result of 426.4 ppm, then the correct reporting of the value is 426.4±5.0 ppm (1σ). That means there is a 68.2% chance a replicate measurement will be within 5.0 ppm of 426.4 ppm.
That is precisely what I question.
Thales
Active member
As was stated earlier in the thread, it ramped up over time when I stopped using GFO. It was also tested by various methods, that produced similar results on multiple tests. Not trusting the perfectness of the numbers is fine, but the generality of them seems pretty solid.
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Thales
Active member
Jim,
Maybe I should have said 'preciseness and accuracy' in my earlier reply. That said, it looks like we may mostly agree.
For instance, people use their hanna checker phosphates devices are report that their phosphate is .04 ppm. Leaving aside the probable practical testing errors, the accuracy of the test, according to the manual, is +- .04 ppm at 25c (no idea how much more it drifts away from 25c). So a test result right in the range that most people are looking for....
I see no practical reason to worry about the difference in you Ca example. Worrying about 426.4 and 425 would fall for me, squarely into the chasing numbers morass.
I translate test results, no matter where they come from, into generalities that make them more practical for me. I find a one off test to be inherently suspect, while tests using the methodology by the same person more useful in trending, but still suspect.
Results by the lab:
Alk = 3.377
Ca = 452.4
Mg = 1337.5
NO3- = 100.7
PO43- = 1.392
How I read them:
Alk= 3 ish, maybe 3.3ish
Ca = 400ish, could be as low as 350
Mg = somewhere between 1200 and 1500
NO3 = seems high
PO43 = seems high
NO3 and PO43 get a 'seems high' translation because I am still not really sure what is the practical problem with these 'high' values. Most likely, I would make an effort to try to bring them down, based mostly on 'because'.
A quick word on the high N03 - I think a whole lot of reefkeepers with successful tanks don't often, if ever test NO3. I know some that when they do test it, it reads off the charts, but everything looks fine. We don't often hear about this on public forums because most people really don't want to get into this kind of discussion.
Maybe I should have said 'preciseness and accuracy' in my earlier reply. That said, it looks like we may mostly agree.
For instance, people use their hanna checker phosphates devices are report that their phosphate is .04 ppm. Leaving aside the probable practical testing errors, the accuracy of the test, according to the manual, is +- .04 ppm at 25c (no idea how much more it drifts away from 25c). So a test result right in the range that most people are looking for....
I see no practical reason to worry about the difference in you Ca example. Worrying about 426.4 and 425 would fall for me, squarely into the chasing numbers morass.
I translate test results, no matter where they come from, into generalities that make them more practical for me. I find a one off test to be inherently suspect, while tests using the methodology by the same person more useful in trending, but still suspect.
Results by the lab:
Alk = 3.377
Ca = 452.4
Mg = 1337.5
NO3- = 100.7
PO43- = 1.392
How I read them:
Alk= 3 ish, maybe 3.3ish
Ca = 400ish, could be as low as 350
Mg = somewhere between 1200 and 1500
NO3 = seems high
PO43 = seems high
NO3 and PO43 get a 'seems high' translation because I am still not really sure what is the practical problem with these 'high' values. Most likely, I would make an effort to try to bring them down, based mostly on 'because'.
A quick word on the high N03 - I think a whole lot of reefkeepers with successful tanks don't often, if ever test NO3. I know some that when they do test it, it reads off the charts, but everything looks fine. We don't often hear about this on public forums because most people really don't want to get into this kind of discussion.
dkeller_nc
New member
Sorry, I should've been more specific. What I mean by "sensitive" is that the actual mass of acetic acid (or ethanol, if one chooses to use vodka) is extremely small relative to the tank/system total volume to get the desired effect. For example, the eventual recommended dosage for a 100 gallon tank after the gradual ramp-up is 66 mL of 5% acetic acid, or 3.4 grams of acetic acid. That works out to 9 ppm, and many of us, including myself, don't use anywhere near that amount.
My dosing, for example, works out to 1 mL of vinegar per 10 gallons, or 1.4 ppm, and that's sufficient to keep the nitrate concentration in my tank water to below the detection limit of the Salifert test.
Hah!
Thanks for the reply.
To be clear:I agree it would not be at all likely;not necessarily "silly" or frivolous or imbecilic,foolish , irrational ,etc..
Setting that characterization aside,the question was meant to illustrate the usefulness of the test results posted for PO4 for this discussion and to imply veracity and competence in the testing overall . I don't expect anyone to make a case to the contrary.
As stated in my earlier post I'm not skeptical about the results you have posted .
Exactness, is not likely with hobby grade test kits and equipment but in the hands of a knowledgeable and disciplined aquarist they provide useful information.
I also agree chasing particular numbers rather than ranges and results is a poor strategy( sometimes made worse by inaccuracy and imprecision)often resulting in interventions that are useless or harmful;using buffers to raise pH and chasing PO4 to zero are good examples ,imo. It really doesn't matter to me whether the calcium is 400 or 45oppm if satisfactory alk can be maintained .
Just noticed you edited out silly. Thanks.
To be clear:I agree it would not be at all likely;not necessarily "silly" or frivolous or imbecilic,foolish , irrational ,etc..
Setting that characterization aside,the question was meant to illustrate the usefulness of the test results posted for PO4 for this discussion and to imply veracity and competence in the testing overall . I don't expect anyone to make a case to the contrary.
As stated in my earlier post I'm not skeptical about the results you have posted .
Exactness, is not likely with hobby grade test kits and equipment but in the hands of a knowledgeable and disciplined aquarist they provide useful information.
I also agree chasing particular numbers rather than ranges and results is a poor strategy( sometimes made worse by inaccuracy and imprecision)often resulting in interventions that are useless or harmful;using buffers to raise pH and chasing PO4 to zero are good examples ,imo. It really doesn't matter to me whether the calcium is 400 or 45oppm if satisfactory alk can be maintained .
Just noticed you edited out silly. Thanks.
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Allmost
New member
if I am not mistaking, you have mentioned on this thread multiple times, that you did not observe any changes to the tank, and its inhabitats when N and P raised to above values.
so either test results are off, or the observation ? high road or low road
or maybe you meant no significant changes were observed ? like no massive die off ... but corals were effected negatively in terms of color and growth and ...
FWIW ... I see my corals looking different depending on my import and export changes ... in every tank I have owned.
PS. I should note again ... as mentioned in page one. I do not test my water ... I do weekly tests for KH [as its easy] and rely on how my corals look ... I try to make them look colorfull and keep growing. if that is happening in my tank with no3 of 100 PPM, then that is fine. it possibly can be cause I do not test. but I do see difference in how they look, following a couple days of overfeeding. or following couple days on underfeeding and skimming more. this also increases the growth of algae [on front glass for example] which proves to me nutrient levels [N and P] were increased.
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Thales
Active member
if I am not mistaking, you have mentioned on this thread multiple times, that you did not observe any changes to the tank, and its inhabitats when N and P raised to above values.
so either test results are off, or the observation ? high road or low road
No reason to think anything is binary. It could easily be, and most likely is, that the tests are generally right and the observations are generally right. Or a million other things.
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Allmost
New member
ok well being a scientist ... I do not think that way. There are laws governing everything ... things dont happen randomly. but thats how I feel
my point, which I am sure you did get, was that change in nutrients = change in corals appearance. yet u have mentioned on here that corals do not react to change in nutrients, which is against everyones observations...
thanks for letting me participate in your thread.
my point, which I am sure you did get, was that change in nutrients = change in corals appearance. yet u have mentioned on here that corals do not react to change in nutrients, which is against everyones observations...
thanks for letting me participate in your thread.
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Thales
Active member
ok well being a scientist ... I do not think that way. There are laws governing everything ... things dont happen randomly. but thats how I feel
But it isn't only a choice between two laws or two outcomes. Reef tanks are complex systems and I think the human tendency to try to boil things down to two choices hurts the overall discussion and learning.
I am almost always leery of whenever someone says 'everyone says' or 'everyone knows', as it is almost never the case. It is not the case that everyone thinks that corals react to a change in nutrients, especially regarding coral coloration, nor is it clear what you mean by 'react' or 'change'.
thanks for letting me participate in your thread.
Allmost
New member
I never said everybody knows or everybody says
I said " which is against everyones observations"
lets not change each others words as that hurts overall discussion and learning.
so please teach us ... are we all seeing things ? or could it be that the gradual changes was not noticed in your tank ? ORRR .... rather corals that need higher nutrients started growing more than the SPS in your tank ? the overall results, looks amazing, your tank is really nice, but we are trying to find relations between nutrients and SPS here, and not overall tank health. [or at least I was lol ]
I said " which is against everyones observations"
lets not change each others words as that hurts overall discussion and learning.
so please teach us ... are we all seeing things ? or could it be that the gradual changes was not noticed in your tank ? ORRR .... rather corals that need higher nutrients started growing more than the SPS in your tank ? the overall results, looks amazing, your tank is really nice, but we are trying to find relations between nutrients and SPS here, and not overall tank health. [or at least I was lol ]
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