Poll, What do you keep you NitrAtes at.
- Thread starter nfored
- Start date
johnptc;2098074; said:
Ah, but doesn't 4.4 x 0 still equal 0 ?? Sorry, just felt like being cheeky...
Not meaning to completely hijack the thread, but I would be curious to learn more about the difference between nitrate-nitrogen and nitrate. Is there anywhere that you can point me towards for some reading? If it wasn't important, I don't think you would have mentioned it.
-Eric
SoCalDiscus;2098420; said:Ah, but doesn't 4.4 x 0 still equal 0 ?? Sorry, just felt like being cheeky...
Not meaning to completely hijack the thread, but I would be curious to learn more about the difference between nitrate-nitrogen and nitrate. Is there anywhere that you can point me towards for some reading? If it wasn't important, I don't think you would have mentioned it.
-Eric
a teaser [SIZE=+2]Understanding the Different Nitrate Units[/SIZE]
[SIZE=-1]by Ellen Campbell[/SIZE] Nitrate is reported in different terms (units) depending on where you live and your field of use. For example, 2 parts per million (ppm) nitrate-N in New YOrk would be reported as 9 ppm nitrate in California.
- To convert from ppm nitrate-N to nitrate, multiply the nitrate-N value by 4.4 (10ppm nitrate-Nx4.4=44 ppm nitrate).
- To convert from ppm nitrate to ppm nitrate-N, multiply the nitrate value by 0.23 (50 ppm nitratex0.23=11.5 ppm nitrate-N).
more depth
NOTES ON NITROGEN TESTS (Dustin Laurence, laurence@alice.caltech.edu)
Tests for nitrogen compounds (ammonia or NH3, nitrite or NH2--, and nitrate
or NH3-) measure the substance in question on one of two scales; ion
concentration or nitrogen-ion concentration. Concentration is generally
expressed in ppm (parts per million). Ion concentration is then written as
ppm NH3, ppm NO2--, or ppm NO3-, and nitrogen-ion concentration is written
as ppm N-NH3, ppm N-NO2--, or ppm N-NO3-. (When these symbols are typeset
in a book or instruction sheet, the number are written as subscripts below
the letters and the minus signs which follow NO2 and NO3 are written as
superscripts; the charges (minus signs) are often omitted entirely.)
The difference between these measures is not difficult to understand, but it
can cause a lot of confusion because it is often not obvious which measure
that a particular author or test kit refers to. First, the bottom line for
those who don't want to know the details:
[N-NH3] (ammonia-nitrogen) = 0.8 [NH3] (ammonia ion)
or
[NH3] = 1.3 [N-NH3]
[N-NO2--] (nitrite-nitrogen) = 0.3 [NO2--] (nitrite ion)
or
[NO2--] = 3.3[N-NO2--]
[N-NO3-] (nitrate-nitrogen) = 0.23 [NO3-] (nitrate ion)
or
[NO3-] = 4.4 [N-NO3-]
Where [] indicates concentration in parts per million (ppm).
Ammonia and nitrite concentrations should be too low to measure with hobby
equipment in a cycled aquarium, so the distinction between the two measures
is rarely useful to the amateur hobbyist; 1.3 times zero is still zero!
However, nitrate concentrations will in general not only be nonzero but
increase over time, and it is important for the aquarist to monitor their
levels as necessary and to know what levels are acceptable for her tank.
Therefore, you can usually buy relatively cheap ammonia and nitrite kits and
spend more on a good nitrate kit.
One general rule of thumb is never buy a kit that asks you to compare the
color of a clear liquid to a color on an opaque chart; comparisons of colors
of vastly different optical depths are very hard to estimate. Good kits
give you a colored transparency for the comparison.
You can't trust the zero of many kits! Do a test on distilled, reverse
osmosis, or de-ionized water; often you will get a false reading. Subtract
this reading from each test of your aquarium water for a somewhat better
estimate of what the true levels are.
Most aquarium authors give recommendations for acceptable nitrate levels in
terms of nitrate ion concentrations. Recommendations for marine tanks range
from 10 to 40ppm nitrate ion for fish-only tanks and <5 to 10ppm nitrate ion
for reef systems, though many fish-only tanks run at much higher levels
(sometimes with no ill effects, and sometimes...). On the other hand, many
tests read in terms of nitrogen-ion concentrations, since this measure is
more commonly used by professionals. Trouble often occurs when the hobbyist
measures her nitrate levels in nitrogen-ion concentrations and unwarily
compares the resulting number with a recommendation in ion concentrations,
possibly resulting in nitrate concentrations up to four times that intended.
If a nitrate test does not mention which scale is being used, it may be
possible to determine this by testing an established, well maintained tank.
However, someone who has access to a well maintained tank usually already
knows the scale of his favorite test, and most often it is the person who
is trying to set up a tank for the first time that needs this information.
A list of common tests and their measure is included at the end of this
section as well.
If you absolutely must use a test that does not mention the scale, it is best
to be safe and assume nitrogen-ion concentration. However, one may
legitimately question the likely quality of a test which does not provide
this information, and a move to a better test is probably indicated.
Now the details: the measure of concentration used on both scales is parts
per million, abbreviated ppm, which means: units of mass of the measured
substance per million units of mass of the final solution. (For aquarist's
purposes, this is identical to milligrams per liter, or mg/l; one liter of
fresh water is almost exactly one kilogram, and a liter of salt water is
only a couple of percent more.)
On the ion scale we measure the mass of the complete ion which makes up the
substance, while in the nitrogen-ion scale we only measure the mass of the
nitrogen atom in that ion. The first scale measures the concentration of
nitrate ions, while the second measures the concentration of nitrogen in
the form of nitrate. In fact, it could be called the "nitrogen as nitrate"
scale.
Which scale is more natural depends on one's intent. Most aquarists are
interested in the toxicity of, say, nitrate ions in aquarium water, in
which case the ion scale is the most natural; it directly measures the
amount of the toxic ion present. On the other hand, a biologist may be
studying the nitrogen cycle in a particular system, and would thus be
interested in measuring the total amount of inorganic nitrogenous wastes
present in a water sample. Then the nitrogen-ion scale is most natural,
since the concentrations can be added directly. One could not add the ion
concentrations for this purpose; this would be exactly like adding apples
and oranges.
The conversions between the scales is easily derived as follows:
mass of the complete ion
[ion] = ------------------------ [nitrogen-ion]
mass of a nitrogen atom
And clearly 1 over this conversion factor is used when converting ion
concentration to nitrogen-ion concentration. The interested reader can
reproduce the above numbers with this formula and the following information.
Masses:
To within a percent, we can use mass of a hydrogen atom (H) = 1, mass of a
nitrogen atom (N) = 14, and mass of an oxygen atom (O) = 16.
Chemical Species Formula Mass
Nitrate ion NO3- 14+3*16=62
Nitrite ion NO2-- 14+2*16=46
Ammonium ion NH4+ 14+4*1=18
Ammonia molecule NH3 14+3*1=17
The calculation for the ammonia conversion factor is complicated by the fact
that in solution ammonia exists in two forms. In a given sample of water,
part of the ammonia will be in the form of ammonia (NH3) and part in the form
of ammonium ions (NH4+). Further, the ratio of ammonia to ammonium is pH
dependent. However, even if we assume that the ammonia present is all in
one form or the other, the difference between the resulting numbers is not
significant for our purposes (1.21 vs 1.29).
The commonly quoted figure of 1.3 probably results from the fact that if
the ratio of the two species was exactly 50%, the conversion factor would
be exactly 1.25. Since at the pH of most aquaria more of the ions are
ammonium than ammonia, the conversion factor must be more than 1.25 and
so we round to 1.3. [This last sentence is a guess on my part, since I
don't really know what the pH of the average freshwater aquarium is. It
should be true for all marine aquaria.]
The following is an (incomplete) list of common tests, the measure used
by each, and comments be various people on the net.
DryTab ion
From Dustin Laurence:
These kits are IMHO almost completely worthless. Buy something
like the SeaTest kits instead for good, fairly inexpensive tests.
Dupla ion?
From Ken Koellner:
English instructions are translated from the German with European
conventions intact. American aquarists beware things like 0,2
for 0.2 .
HACH Saltwatermaster kit nitrogen-ion
From Mike Loughlin:
Designed for aquaculture, sensitive to low concentrations. Excellent
technical support. Cost: $35.75 in the 1992 catalog.
HATCH low range nitrate nitrogen-ion
From Greg Smith:
Range: 0-1ppm N-NO3 in .02 increments. Smallest readable
increment: .02ppm. Cost: ~55. Comments: repeatable, consistent, kit
uses colorwheel. This is the best kit I have used, better than
lamotte, seatest, kordon. Number of tests: (30, 50? not sure).
Keith Rogers Adds:
Note that you get erroneous results in salt water unless you get the
proper SW version of NitraVer 6 (one of the reagents used). They will
*not* substitute the SW reagent in place of the FW one. So, if you
need the kit for SW you also need to buy the other reagent for an
extra $18.50. Shipping cost is $8. The up side to this is you get a
FW and SW nitrate kit which is better than all the rest bar none.
Kordon low range nitrate nitrogen
From Greg Smith:
Range: 0-55ppm NO3. Smallest readable increment: 5ppm. Cost ~10.
Number of tests: (10 or 20 not sure). Comments: good kit.
Lamotte nitrogen-ion?
SeaTest nitrogen-ion
From Dustin Laurence:
Good kits for average aquarists. Reef aquarists will want a better
(and more expensive!) nitrate kit after their reef has matured.
From Ray Wallace (on nitrate kit):
Range: 0-12 mg/L (ppm) and 0-100 mg/L (ppm) Nitrate-Nitrogen (NO3-N)
scales. Uses a slide with gradual color scales. Smallest numbered
increment is 1.2. 25 tests using premeasured powder in packets.
NOTES ON NITROGEN TESTS (Dustin Laurence, laurence@alice.caltech.edu)
Tests for nitrogen compounds (ammonia or NH3, nitrite or NH2--, and nitrate
or NH3-) measure the substance in question on one of two scales; ion
concentration or nitrogen-ion concentration. Concentration is generally
expressed in ppm (parts per million). Ion concentration is then written as
ppm NH3, ppm NO2--, or ppm NO3-, and nitrogen-ion concentration is written
as ppm N-NH3, ppm N-NO2--, or ppm N-NO3-. (When these symbols are typeset
in a book or instruction sheet, the number are written as subscripts below
the letters and the minus signs which follow NO2 and NO3 are written as
superscripts; the charges (minus signs) are often omitted entirely.)
The difference between these measures is not difficult to understand, but it
can cause a lot of confusion because it is often not obvious which measure
that a particular author or test kit refers to. First, the bottom line for
those who don't want to know the details:
[N-NH3] (ammonia-nitrogen) = 0.8 [NH3] (ammonia ion)
or
[NH3] = 1.3 [N-NH3]
[N-NO2--] (nitrite-nitrogen) = 0.3 [NO2--] (nitrite ion)
or
[NO2--] = 3.3[N-NO2--]
[N-NO3-] (nitrate-nitrogen) = 0.23 [NO3-] (nitrate ion)
or
[NO3-] = 4.4 [N-NO3-]
Where [] indicates concentration in parts per million (ppm).
Ammonia and nitrite concentrations should be too low to measure with hobby
equipment in a cycled aquarium, so the distinction between the two measures
is rarely useful to the amateur hobbyist; 1.3 times zero is still zero!
However, nitrate concentrations will in general not only be nonzero but
increase over time, and it is important for the aquarist to monitor their
levels as necessary and to know what levels are acceptable for her tank.
Therefore, you can usually buy relatively cheap ammonia and nitrite kits and
spend more on a good nitrate kit.
One general rule of thumb is never buy a kit that asks you to compare the
color of a clear liquid to a color on an opaque chart; comparisons of colors
of vastly different optical depths are very hard to estimate. Good kits
give you a colored transparency for the comparison.
You can't trust the zero of many kits! Do a test on distilled, reverse
osmosis, or de-ionized water; often you will get a false reading. Subtract
this reading from each test of your aquarium water for a somewhat better
estimate of what the true levels are.
Most aquarium authors give recommendations for acceptable nitrate levels in
terms of nitrate ion concentrations. Recommendations for marine tanks range
from 10 to 40ppm nitrate ion for fish-only tanks and <5 to 10ppm nitrate ion
for reef systems, though many fish-only tanks run at much higher levels
(sometimes with no ill effects, and sometimes...). On the other hand, many
tests read in terms of nitrogen-ion concentrations, since this measure is
more commonly used by professionals. Trouble often occurs when the hobbyist
measures her nitrate levels in nitrogen-ion concentrations and unwarily
compares the resulting number with a recommendation in ion concentrations,
possibly resulting in nitrate concentrations up to four times that intended.
If a nitrate test does not mention which scale is being used, it may be
possible to determine this by testing an established, well maintained tank.
However, someone who has access to a well maintained tank usually already
knows the scale of his favorite test, and most often it is the person who
is trying to set up a tank for the first time that needs this information.
A list of common tests and their measure is included at the end of this
section as well.
If you absolutely must use a test that does not mention the scale, it is best
to be safe and assume nitrogen-ion concentration. However, one may
legitimately question the likely quality of a test which does not provide
this information, and a move to a better test is probably indicated.
Now the details: the measure of concentration used on both scales is parts
per million, abbreviated ppm, which means: units of mass of the measured
substance per million units of mass of the final solution. (For aquarist's
purposes, this is identical to milligrams per liter, or mg/l; one liter of
fresh water is almost exactly one kilogram, and a liter of salt water is
only a couple of percent more.)
On the ion scale we measure the mass of the complete ion which makes up the
substance, while in the nitrogen-ion scale we only measure the mass of the
nitrogen atom in that ion. The first scale measures the concentration of
nitrate ions, while the second measures the concentration of nitrogen in
the form of nitrate. In fact, it could be called the "nitrogen as nitrate"
scale.
Which scale is more natural depends on one's intent. Most aquarists are
interested in the toxicity of, say, nitrate ions in aquarium water, in
which case the ion scale is the most natural; it directly measures the
amount of the toxic ion present. On the other hand, a biologist may be
studying the nitrogen cycle in a particular system, and would thus be
interested in measuring the total amount of inorganic nitrogenous wastes
present in a water sample. Then the nitrogen-ion scale is most natural,
since the concentrations can be added directly. One could not add the ion
concentrations for this purpose; this would be exactly like adding apples
and oranges.
The conversions between the scales is easily derived as follows:
mass of the complete ion
[ion] = ------------------------ [nitrogen-ion]
mass of a nitrogen atom
And clearly 1 over this conversion factor is used when converting ion
concentration to nitrogen-ion concentration. The interested reader can
reproduce the above numbers with this formula and the following information.
Masses:
To within a percent, we can use mass of a hydrogen atom (H) = 1, mass of a
nitrogen atom (N) = 14, and mass of an oxygen atom (O) = 16.
Chemical Species Formula Mass
Nitrate ion NO3- 14+3*16=62
Nitrite ion NO2-- 14+2*16=46
Ammonium ion NH4+ 14+4*1=18
Ammonia molecule NH3 14+3*1=17
The calculation for the ammonia conversion factor is complicated by the fact
that in solution ammonia exists in two forms. In a given sample of water,
part of the ammonia will be in the form of ammonia (NH3) and part in the form
of ammonium ions (NH4+). Further, the ratio of ammonia to ammonium is pH
dependent. However, even if we assume that the ammonia present is all in
one form or the other, the difference between the resulting numbers is not
significant for our purposes (1.21 vs 1.29).
The commonly quoted figure of 1.3 probably results from the fact that if
the ratio of the two species was exactly 50%, the conversion factor would
be exactly 1.25. Since at the pH of most aquaria more of the ions are
ammonium than ammonia, the conversion factor must be more than 1.25 and
so we round to 1.3. [This last sentence is a guess on my part, since I
don't really know what the pH of the average freshwater aquarium is. It
should be true for all marine aquaria.]
The following is an (incomplete) list of common tests, the measure used
by each, and comments be various people on the net.
DryTab ion
From Dustin Laurence:
These kits are IMHO almost completely worthless. Buy something
like the SeaTest kits instead for good, fairly inexpensive tests.
Dupla ion?
From Ken Koellner:
English instructions are translated from the German with European
conventions intact. American aquarists beware things like 0,2
for 0.2 .
HACH Saltwatermaster kit nitrogen-ion
From Mike Loughlin:
Designed for aquaculture, sensitive to low concentrations. Excellent
technical support. Cost: $35.75 in the 1992 catalog.
HATCH low range nitrate nitrogen-ion
From Greg Smith:
Range: 0-1ppm N-NO3 in .02 increments. Smallest readable
increment: .02ppm. Cost: ~55. Comments: repeatable, consistent, kit
uses colorwheel. This is the best kit I have used, better than
lamotte, seatest, kordon. Number of tests: (30, 50? not sure).
Keith Rogers Adds:
Note that you get erroneous results in salt water unless you get the
proper SW version of NitraVer 6 (one of the reagents used). They will
*not* substitute the SW reagent in place of the FW one. So, if you
need the kit for SW you also need to buy the other reagent for an
extra $18.50. Shipping cost is $8. The up side to this is you get a
FW and SW nitrate kit which is better than all the rest bar none.
Kordon low range nitrate nitrogen
From Greg Smith:
Range: 0-55ppm NO3. Smallest readable increment: 5ppm. Cost ~10.
Number of tests: (10 or 20 not sure). Comments: good kit.
Lamotte nitrogen-ion?
SeaTest nitrogen-ion
From Dustin Laurence:
Good kits for average aquarists. Reef aquarists will want a better
(and more expensive!) nitrate kit after their reef has matured.
From Ray Wallace (on nitrate kit):
Range: 0-12 mg/L (ppm) and 0-100 mg/L (ppm) Nitrate-Nitrogen (NO3-N)
scales. Uses a slide with gradual color scales. Smallest numbered
increment is 1.2. 25 tests using premeasured powder in packets.
Ha Ha Ha, I had to ask! I'll get back to you in about a week with some questions!
By the way, Thank you John, I will do my best to digest all of it.
-Eric
By the way, Thank you John, I will do my best to digest all of it.
-Eric
SoCalDiscus;2098569; said:
the main thing is to know which test kit you have.....
eg on a nitrate kit maybe 40ppm is tops but if its nitrate-nitrogen it is only 9-10 ppm
easy to get it wrongJohn, that just went right over my head, whooosh!
i dont test anymore, just do my weekly waterchanges.
i dont test anymore, just do my weekly waterchanges.
wow thats was quite a post.
umm my nitrates are actually pretty high. i dont do enough water changes as i should (like none for the past year... maybe 1 i can't remember :O)
lol i tested them today at work (PetSmart) and i didnt look at the number but the strip thing was bright pink. darker than it should be i know. lol
umm my nitrates are actually pretty high. i dont do enough water changes as i should (like none for the past year... maybe 1 i can't remember :O)
lol i tested them today at work (PetSmart) and i didnt look at the number but the strip thing was bright pink. darker than it should be i know. lol
wow you work at petsmart and your water parameters are off the charts?? not surpising!!! lol kidding! but yeah you need to start getting back on track with the WCs. definately not good for your fish(the_squared_man)^2;2098595;2098595 said:
