Nitrates Tested Salifert vs. API

[DRC]

It is not just about the accuracy of the tests. It's the interference with other ions such as chloride. Like the common expression, take the nitrate test result with a grain of salt

I have no problem people checking out water quality by any means they have. It means they care. It is just that there are better ways

That was some serious nerd humor

 

[Coryloach]

Several techniques have been developed that can detect nitrate down to 1.5 nanomolar in seawater. If I did the math correctly, that's 0.000412023 ppm nitrate. I don't think interference from chloride is that big of a problem...

Care to share the technology they used to test the nitrates in your quoted example?
It is the home test kits that aren't accurate. The most accurate method as far as I am aware is high performance liquid chromatography. It is not something you can do at home.

 

[Coryloach]

So a little HLLE on a Tilapia, or Bluegill, may be of little consequence when the fish is packaged and ready to cook.
So those high acceptable nitrate numbers for aquacultured fish, might mean something totally different to an aquarist that wants a stunning specimen in a tank, for an extended period of time.

Definitely a valid point and something to keep in mind. However, what I find interesting in these studies is that high nitrates are accompanied by elevated nitrites and their suspicion falls on denitrification in such systems also raising the nitrite levels. Almost every study on high nitrates has detected elevated chronic nitrite.
In fresh water we know nitrites are way more toxic than nitrates and the symptoms on fish can be attributed to either as they cause the exact same damage, nitrates being converted to nitrites in the fish's gills.

One thing to keep in mind though is that an efficient biofilter will be an efficient nitrate producer only if oxygen levels are high, because it is mainly nitrification that occurs. This is the scenario one wants actually. The alternative is denitrification and production of byproducts such as hydrogen sulfide, nitrite and ammonia.

 

[tiger15]

Lot of misinformation !!!

Almost every study on high nitrates has detected elevated chronic nitrite.
. . . . nitrates being converted to nitrites in the fish's gills.

In a fully cycled tank, due to fast conversion to nitrate, ammonia and nitrite are non detectable by home testing kits even at high nitrate levels. Fish gills excrete ammonia and do not convert nitrate back to nitrite.

The alternative is denitrification and production of byproducts such as hydrogen sulfide, nitrite and ammonia.

Anaerobic condition can generate hydrogen sulfide in the presence of sulfide, not a by product of denitrification. Nitrite and ammonia aren't generated by denitrification. Ammonia is excreted by fish gills or bacterial digestion of protein. Nitrite is an intermediate by product of nitrification process and should not be detectable in a cycled tank.

 

[Coryloach]

Lot of misinformation !!!


In a fully cycled tank, due to fast conversion to nitrate, ammonia and nitrite are non detectable by home testing kits even at high nitrate levels. Fish gills excrete ammonia and do not convert nitrate back to nitrite.


Anaerobic condition can generate hydrogen sulfide in the presence of sulfide, not a by product of denitrification. Nitrite and ammonia aren't generated by denitrification. Ammonia is excreted by fish gills or bacterial digestion of protein. Nitrite is an intermediate by product of nitrification process and should not be detectable in a cycled tank.

Sorry mate,but the misinformed one is you.

 

[esoxlucius]

I must say i'm very interested in this now. I certainly didn't know that if your nitrate is very high you will also start showing nitrite on your tests. I've always thought that in a settled and healthy tank, unless all of a sudden you altered the bio load drastically, then your ammonia and nitrite are 0ppm on a home testing kit, whatever your nitrate reading.

What ppm nitrate figure are we talking about here that will also mean you will have nitrite as well? I don't suppose any of us have let our nitrate get that out of hand that nitrite is showing too, unless the boffins have proved it in lab conditions.

 

[Coryloach]

See,aquariums are not a static point in time when one happens to test their water. The microbial activity and production and reduction of toxins is an ongoing process that fluctuates as we speak and can be influenced by other factirs as simple as what you fed your fish today.

In relation to nitrate and nitrite,I posted a link to an old discussion about it on the first page here. I have quoted a ton of studies there and their findings.

tiger15 I am not going to go into a battle proving my every word to someone that doesnt bother elaborate themselves.

Majority of the information I have shared with my own words can be found in studies on Recirculating Aquaculture systems and Biofloc Technology,also microbiology studies in relation to fish and shrimp farming,years of reading...

 

[LBDave]

I have used both API and Salifert test kits. When API is fresh and you shake solution2 hard, it will give comparable results to Salifert. Over time as API solution2 is aged, the test concentration is off due to non uniform dispensing in the past, API test results are no longer comparable to Salifert. Salifert uses powder for the second test agent, so the concentration won’t change as long as you measure a correct level cup full of the agent. So Salifert will give you consistent results throughout.

API color chart is a joke. If 10-20 and 40-80 have identical color, why not label with two colors instead of lying with four colors. Salifert doesn’t lie about the color resolution, and has a refined option to read lower concentrations. So my conclusion is Salifert gives more consistent results and is not sensitive to shaking and aging. Without comparison to lab results, I am not able to assess which one is closer to the true nitrate concentration, just one is more consistent and thereby more reliable than the other.

As to nitrate harm to fish, don’t be alarmed to see high nitrate concentration if you have a heavily stocked tank as long as you do frequent WC. Nitrate is a proxy indicator of general pollution of many unknown and untested pollutants. Nitrate up to 100 ppm has been demonstrated to be harmless to fish in planted tanks where the source of nitrate is principally from dosing nitrate fertilizer. I dose about 20 ppm of nitrate after each weekly 75% WC in my planted cichlid tank. The stocking is so heavy that the pre WC nitrate is in the 40 ppm range despite plants stripping nitrogen.

I agree...when the Nitrate reading is lower the Salifert seems more accurate. Both can show you if you are having issues with Nitrates. Which is really as far as I take this. Not a chemist.

 

[LBDave]

Seems my thread was awaken from the dead by the biology crowd.
I'll just watch.

 

[squint]

Care to share the technology they used to test the nitrates in your quoted example?
It is the home test kits that aren't accurate. The most accurate method as far as I am aware is high performance liquid chromatography. It is not something you can do at home.

https://www.sciencedirect.com/science/article/abs/pii/S0165993607002671





Seems like just about all the methods are included. It may not be the method that's limiting.