Nitrate test

[zolta]

I recently bought a Seachem nitrate test kit and I am finding it difficult to determine the outcome.  I find the colour difficult to read in the 3 to 15 mg/l area.  It all looks the same to me.  I guess I am getting old and colour blind.  Has anyone have experience with a different test kit where the colour change is more pronounced?  Thanks in advance.

[wolfiewill]

I have trouble with this test too. I find an overhead, blue-white flourescent light and I take my glasses off and get real close with both in my field of vision is the only way. I've never tried the API test kit though. Perhaps someone else has tried it?

[Greatwhite]

I find holding white paper behind the test tubes helps a lot. But yeah - it's not a big variation in the color to get an "exact" reading.

I hate doing water tests... At least testing my pool water just uses a simple test strip.

[exv152]

I've tried hagen nutrafin, API and seachem, and prefer the API kit even though anything over 20ppm is similar in colour hue.

[wolfiewill]

I've tried hagen nutrafin, API and seachem, and prefer the API kit even though anything over 20ppm is similar in colour hue.

Yes, that's what I find with the Seachem test kit. But I'm targeting 10 ppm, so I really don't need to really know how much above target the result is, only that it is above. And when it is, I do a water change. And there's the advantage of PPS, eh. So I suppose it's a qualitative test for me, not a quantitative one. See, there are advantages to being lazy!

[zolta]

Thanks for the input guys,

With the Seachem, for me, the little palette used is what i have discovered difficult.  I will try Greg's method though.  To bad Hanna does not make a nitrate test.  Perhaps when he Seachem runs out, I'll try a different brand. 

[wolfiewill]

Thanks for the input guys,

With the Seachem, for me, the little palette used is what i have discovered difficult.  I will try Greg's method though.  To bad Hanna does not make a nitrate test.  Perhaps when he Seachem runs out, I'll try a different brand. 

I'm actually in the process of finding a more precise NO3 test kit but have only given it one attempt. Still, if anyone has an accurate one I'd appreciate knowing about it. I have a Hanna phosphate kit and they are terrific, but not cheap.

[exv152]

Have you tried the salifert nitrate test? Not sure if it's just for sw, but the colour chart is more detailed. I think David has them.

[Ron]

I'm actually in the process of finding a more precise NO3 test kit but have only given it one attempt. Still, if anyone has an accurate one I'd appreciate knowing about it. I have a Hanna phosphate kit and they are terrific, but not cheap.

I think I've tried just about every kit out there over the years, and settled on the ones from LaMotte. These aren't cheap either, but they work!

[wolfiewill]

Have you tried the salifert nitrate test? Not sure if it's just for sw, but the colour chart is more detailed. I think David has them.

Salifert is for salt water only.

[wolfiewill]

I think I've tried just about every kit out there over the years, and settled on the ones from LaMotte. These aren't cheap either, but they work!

Yes, I like the LaMotte test kit for phosphate, but the one I found online has a limit of 10 ppm. Does LaMotte have one for slightly higher levels? I would prefer the range of the Seachem kit, 0 to 40 or 50. At the moment the Seachem is reasonably good for the 1 to 20. As Zolta said, beyond 20 ppm it is very hard to differentiate.

[Ron]

Yes, I like the LaMotte test kit for phosphate, but the one I found online has a limit of 10 ppm. Does LaMotte have one for slightly higher levels? I would prefer the range of the Seachem kit, 0 to 40 or 50. At the moment the Seachem is reasonably good for the 1 to 20. As Zolta said, beyond 20 ppm it is very hard to differentiate.

If you are trying to measure levels higher than the top range of the kit, you can always cut your sample water by half (or two thirds or four fifths) with distilled water, then multiply your result by two (or three or five). You just have to be confident of the quality of your distilled dilutant.

[wolfiewill]

If you are trying to measure levels higher than the top range of the kit, you can always cut your sample water by half (or two thirds or four fifths) with distilled water, then multiply your result by two (or three or five). You just have to be confident of the quality of your distilled dilutant.

Yah, I hadn't thought of that. Good idea!