Nitrate question

[Jakef150]

Simple Q

Is swing 0-5ppm bad ? It happens some day it shows 0 and other time it shows 5ppm

I used new test kit API nitrate.

Thanks
Jake

 

[k1600]

I would look at the test kit and not the tank. I wouldn't use API to test nitrate. Try using something better like Salifert.
Ken