Acurate NO3- test for low density measurments?

[Pszemol]

I've been using Aquarium Pharmaceuticals test til now
since I had high nitrate levels, in my reef...
Over 20mg/l - After incorporating a refugium with algae
and fast growing Pulsing Xenia lowered down my nitrates
fall far below 10mg/l and made my NO3 measurements with
my tests very difficult. The test scale shows
only three yellow bands for NO3 levels 0, 5 and
10mg and then two orange for 20 and 40mg...
It is very hard to tell which yellow it is, when
I take tests - I can tell is more orange than Zero,
but less then 10mg, maybe 5mg... It is not acurate!

Do you know any more acurate test for nitrates in
the lower range? Is there a easy way to tell how
much NO3- I have with the acuracy to a single mg/l
and better? Or is it not doable with aquarium tests?

[Boomer]

Yes there are, HACH makes one for $50 that goes down to .02 NO3-N

NI-14
cat # 14161-00

--
Boomer

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If You See Me Running You Better Catch-Up
"Pszemol" > wrote in message ...
: I've been using Aquarium Pharmaceuticals test til now
: since I had high nitrate levels, in my reef...
: Over 20mg/l - After incorporating a refugium with algae
: and fast growing Pulsing Xenia lowered down my nitrates
: fall far below 10mg/l and made my NO3 measurements with
: my tests very difficult. The test scale shows
: only three yellow bands for NO3 levels 0, 5 and
: 10mg and then two orange for 20 and 40mg...
: It is very hard to tell which yellow it is, when
: I take tests - I can tell is more orange than Zero,
: but less then 10mg, maybe 5mg... It is not acurate!
:
: Do you know any more acurate test for nitrates in
: the lower range? Is there a easy way to tell how
: much NO3- I have with the acuracy to a single mg/l
: and better? Or is it not doable with aquarium tests?

[Pszemol]

Thanks.
What is the difference between Hach test and AP test I am using?
Are they just more precise or do they use different principle?
Is it possible at all to catch precisely this color difference?
Or I would have to use electronic colorimeter? :-)))

"Boomer" > wrote in message ...
> Yes there are, HACH makes one for $50 that goes down to .02 NO3-N
>
> NI-14
> cat # 14161-00
>
> --
> Boomer
>
> Want to talk chemistry ? The Reef Chemistry Forum
> http://www.reefcentral.com/vbulletin/index.php
>
> Want to See More ?
> Please Join Our Growing Membership
> www.coralrealm.com
>
> If You See Me Running You Better Catch-Up
> "Pszemol" > wrote in message ...
> : I've been using Aquarium Pharmaceuticals test til now
> : since I had high nitrate levels, in my reef...
> : Over 20mg/l - After incorporating a refugium with algae
> : and fast growing Pulsing Xenia lowered down my nitrates
> : fall far below 10mg/l and made my NO3 measurements with
> : my tests very difficult. The test scale shows
> : only three yellow bands for NO3 levels 0, 5 and
> : 10mg and then two orange for 20 and 40mg...
> : It is very hard to tell which yellow it is, when
> : I take tests - I can tell is more orange than Zero,
> : but less then 10mg, maybe 5mg... It is not acurate!
> :
> : Do you know any more acurate test for nitrates in
> : the lower range? Is there a easy way to tell how
> : much NO3- I have with the acuracy to a single mg/l
> : and better? Or is it not doable with aquarium tests?
>
>

[Boomer]

I don't know what reagents the AP uses. The HACH uses what is called the Cadmium method
and a color wheel. It has two ranges 0-1 and 0-10. The color disk is about 4" in dial and
has a slow progressive color change from very light brown to dark brown. Some kits with
the same method have a change from a light pinkish purple to dark pinkish purple, such as
the La Motte. Most good test kits use this method. They work by a diazotization coupling
reaction, after reduction to nitrate by cadmium.

You can't use a electronic colorimeter, they work off of light and light
refraction/reflection. Seawater is not FW. Light does not travel through it the same. None
of these kits are acceptable for seawater, as there is no std to compare them to.
--
Boomer

Want to talk chemistry ? The Reef Chemistry Forum
http://www.reefcentral.com/vbulletin/index.php

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Please Join Our Growing Membership
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If You See Me Running You Better Catch-Up
"Pszemol" > wrote in message ...
: Thanks.
: What is the difference between Hach test and AP test I am using?
: Are they just more precise or do they use different principle?
: Is it possible at all to catch precisely this color difference?
: Or I would have to use electronic colorimeter? :-)))
:
: "Boomer" > wrote in message
...
: > Yes there are, HACH makes one for $50 that goes down to .02 NO3-N
: >
: > NI-14
: > cat # 14161-00
: >
: > --
: > Boomer
: >
: > Want to talk chemistry ? The Reef Chemistry Forum
: > http://www.reefcentral.com/vbulletin/index.php
: >
: > Want to See More ?
: > Please Join Our Growing Membership
: > www.coralrealm.com
: >
: > If You See Me Running You Better Catch-Up
: > "Pszemol" > wrote in message ...
: > : I've been using Aquarium Pharmaceuticals test til now
: > : since I had high nitrate levels, in my reef...
: > : Over 20mg/l - After incorporating a refugium with algae
: > : and fast growing Pulsing Xenia lowered down my nitrates
: > : fall far below 10mg/l and made my NO3 measurements with
: > : my tests very difficult. The test scale shows
: > : only three yellow bands for NO3 levels 0, 5 and
: > : 10mg and then two orange for 20 and 40mg...
: > : It is very hard to tell which yellow it is, when
: > : I take tests - I can tell is more orange than Zero,
: > : but less then 10mg, maybe 5mg... It is not acurate!
: > :
: > : Do you know any more acurate test for nitrates in
: > : the lower range? Is there a easy way to tell how
: > : much NO3- I have with the acuracy to a single mg/l
: > : and better? Or is it not doable with aquarium tests?
: >
: >