Water Testing

[Opathy]

I have an API master water testing kit and also an Aquarium Coop test strip kit.  
I’ve noticed there is quite a disparity in the Nitrate test results.  The nitrate readings with the strips are always in the safe zone but with the master kit the results are way higher.  I use RO water and add minerals back in with equilibrium.  Even changing 50% water twice a week I cannot get the master kit to test below 40 ppm.  The Co-op kit is showing fine.  I can go 2 weeks using the Co-op kit before a water change.

Any ideas?

[tolstoy21]

I also see differences between the test strips and the API master kit.

I have found the API results to be accurate when measured against a professional water test or my well/tap water.

I used the coop strips all the time, but if I need a nitrate reading, I break out the API drops.

Also, test your source water and see what the API kit says. My tap water has 40ppm nitrates, which has also been confirmed by professional lab testing. 

Also, also . . . you're probably doing this already, but just to check, make sure you're following the annoying API nitrate directions to the letter, which means lots of shakey-shakey of the solution.

Edited September 29, 2023 by tolstoy21

[Galabar]

I think the thing to look for is consistency in the tests.  I would use the API test kit as the actual value, but match the Aquarium Co Op test strip color to what the API test kit is reading.

In other words, re-write the value for the Aquarium Co Op colors to match the API test kit.  That way, you still have a convenient way to test (I hate shaking that API test kit nitrate bottle #2 🙂 ).

 

[Opathy]

Thanks for the comments.  I’ll think I stick with the strips because I’m tired of chasing 

those nitrate numbers with the master kit.

 

[tolstoy21]

On 9/29/2023 at 4:09 PM, Galabar said:

I think the thing to look for is consistency in the tests.  I would use the API test kit as the actual value, but match the Aquarium Co Op test strip color to what the API test kit is reading.

In other words, re-write the value for the Aquarium Co Op colors to match the API test kit.  That way, you still have a convenient way to test (I hate shaking that API test kit nitrate bottle #2 🙂 ).

 

I tend to do that as well.  Additionally, when I use the strips I'm just looking to see if the colors have changed from the last time I have checked. I know what colors equal water that my fish do well in, so when I see different colors, I know something is off and will either break out the API kit, or just do a water change.