api vs salifert nitrite testing wild difference

[ghill]

I am getting wildly differing results measuring nitrites (NO3) in my 20 gallon reef cycling tank (now 3 weeks in). API says 5.0 Salifert says 0.1. Ammonia going to "0" overnight for 3 nights. Boost back to 1-2. This am boosted to 2.0 and dropped to 1.0 seven hours later. Suspect I am getting close to the end of cycling, but this API vs Salifert delta bothers me. Who to believe?

 

[Dan_P]

I am getting wildly differing results measuring nitrites (NO3) in my 20 gallon reef cycling tank (now 3 weeks in). API says 5.0 Salifert says 0.1. Ammonia going to "0" overnight for 3 nights. Boost back to 1-2. This am boosted to 2.0 and dropped to 1.0 seven hours later. Suspect I am getting close to the end of cycling, but this API vs Salifert delta bothers me. Who to believe?

Are you testing nitrite NO2 or nitrate NO3?

 

[ghill]

NO2 nitrite... sorry

 

[Dan_P]

NO2 nitrite... sorry

Your system has a big enough population of ammonia consuming bacteria but the nitrite consuming bacteria maybe not yet. Most folks don’t wait though. As for the test result difference, did you measure nitrite at the seven hour point?

 

[ghill]

Yes... both were measured at the same time. Nitrates, NO3, are running about 20. Calcium at 400. Alkalinity at 1100. PH at 8 and salinity at 1.025. Been cycling since 23 January 24.

 

[Dan_P]

Yes... both were measured at the same time. Nitrates, NO3, are running about 20. Calcium at 400. Alkalinity at 1100. PH at 8 and salinity at 1.025. Been cycling since 23 January 24.

The nitrate test gives high results when nitrite is present.

As for nitrite, I would tend to use the Salifert results.

 

[twentyleagues]

If you have 20 nitrate you are cycled. Sounds like its doing what it should. I dont know which test is at fault if either for the difference between them.

 

[taricha]

I dunno. If you are adding 1-2ppm ammonia 3 days in a row in a newly cycled tank, I might believe the high NO2 number more than the near zero.
"5ppm" NO2 really just means more color than you can easily measure.

Mix up a little new clean salt water, test both new salt water and tank water side by side with the API NO2-nitrite and post a picture. (If you really want to know. It's not that crucial)

 

[Randy Holmes-Farley Verified Community Expert]

Mix up a little new clean salt water, test both new salt water and tank water side by side with the API NO2-nitrite and post a picture. (If you really want to know. It's not that crucial)

That sounds like a good plan to me.

In the end, it likely doesn't matter what the nitrite is, but if you want to know which kit, if either, is more accurate, I'd do that.

 

[ghill]

will do.... this morning API says 2.0 and Salifert says 1.0. Perhaps I should blame testing/er error on the 5.0!