API Nitrate Kit Failure

[tackful]

Hi,
Even though the expiration dates on the two bottles are 10/2019 and 11/2019, my kit no longer measures nitrates. Even when I saturate the test tube with a high concentration of kno3, it still reads 0. Is this a common problem, or maybe just a bad batch? Thanks.

 

[tanker]

You need to shake the chemicals before adding. I MEAN REALLY shake them, and shake for about 30secs to a min.

 

[tackful]

Yes, am quite familiar with the process, having used the API kit for several years. This is the first time I've ever had one that failed.

 

[Rbishop]

Bottles can become contaminated at times...not saying it happened, but always a possibility.

 

[dougall]

Maybe just give API a call.. I imagine they will help you out.

 

[FreshyFresh]

High concentrations may not read properly with these test kits as well. I have had an over-range high reading indicate "zero ppm" for the API nitrite kit.

What are the specifics and water change regimen of the tank you are testing? I'm not saying you have an issue there, just trying to help troubleshoot your concern.

 

[tackful]

My tank is usually P=2 and N=10 or 20 with a 50% WC every two weeks. Recently I fell behind and on maintenance and experienced a green slime algae outbreak, which I believe is caused by low nitrates. Tank is back to normal now, but I want to avoid low N in the future.

 

[tackful]

You need to shake the chemicals before adding. I MEAN REALLY shake them, and shake for about 30secs to a min.

Turns out you were right. I learned elsewhere that if Bottle #2 is allowed to sit for too long undisturbed, the solution can settle to the point where previous shakings are no longer adequate. Was very vigorous with the bottle this time, and obtained complete agreement with the results of a new kit. Thanks.

 

[tanker]

Glad to be of help.