How on earth do you interpret nitrate tests?

[Dkeller_nc]

None of the non-digital kits are going to give you highly accurate nitrate readings. It's basically going to be "best guess" or "open to interpretation" based on how well you view the color palette. I think the whole idea is to let you know whether you're in the ballpark so you can gauge and plan accordingly.

Red Sea: 0, 2, 5, 10, 20, 50
Salifert: 0, 2, 5, 10, 25, 50, 100
Nyos: 0, 1, 3, 5, 12, 25, 40, 65, 95, 160

One addition to this. The Salifert kit gives you an option to either read through the top of the vial or through the side. The path length when reading through the side of the cuvette is 10 times the path length when reading through the top. That allows interpretation of the nitrate level as 0, 0.2, 0.5, 1.0, 2.5, 5 and 10 ppm, thus in theory giving you a low level/high sensitivity option. However, you still have the color/density interpretation challenge inherent in all eyeball colorimetric nitrate tests.

 

[blaxsun]

One addition to this. The Salifert kit gives you an option to either read through the top of the vial or through the side. The path length when reading through the side of the cuvette is 10 times the path length when reading through the top. That allows interpretation of the nitrate level as 0, 0.2, 0.5, 1.0, 2.5, 5 and 10 ppm, thus in theory giving you a low level/high sensitivity option. However, you still have the color/density interpretation challenge inherent in all eyeball colorimetric nitrate tests.

I think most people like the Salifert test as it's only 3 minutes.

 

[Dkeller_nc]

Yeah, it's convenient and easy to use, though not so easy to interpret as are all eyeballed test kits. I suppose this will vary depending on the particular reefer's personality, but I don't use nitrate tests very often - perhaps once every 2 or 3 weeks on well established tanks.

 

[RocksNStuff]

I had the same problem with pH tests. I finally broke down and got a digital pH probe and calibration powder.

 

[blaxsun]

I had the same problem with pH tests. I finally broke down and got a digital pH probe and calibration powder.

I have the Hanna digital ones, but I still picked up the Nyos nitrate and phosphate tests because they're very easy to use and read. And accurate.

 

[PeterC99]

Is it just me or is this impossible?

Are you viewing these results under leds? LEDs have red tones in them and will skew your results.

Try to review results under natural sunlight.