Nitrate Pro Test Kit?

[WVReefJunkie]

I have a test kit that gives me a darker purple color than the highest reading on the color wheel doing a high reading range test. So I noticed the test kit expired in 2017. So my question is has anyone experienced this issue with their test kit or Am I doing the test wrong? Thanks

 

[Fudsey]

It most likely is because it has expired. I have had this issue in the past with a different test kit.

 

[garbled]

I have very recently with the red sea kit, but I'm reasonably certain I have high nitrates in the tank right now, so I assume it's correct.

 

[WVReefJunkie]

Api-zero nitrate
Salifert-25 ppm nitrate
Red Sea Pro-Over 64 ppm nitrate