api nitrate test kit

[ihavtats29]

mine is way off , with the api kit i get a consistant reading of 80 ppm in all my tanks and 40 ppm in NSW , i rechecked it with my backup redsea test kit a get 20 ppm in the new tank , 5 in my 90 and 5 in my 10, 0 in NSW, has anyone else had this issue?

 

[Mako Shark II]

That's weird. Did you re-test??

 

[ihavtats29]

multiple times

 

[mempho reefer]

is it an old test kit? that can have an impact on the results. api kits seem to have a limited shelf life. i think salifert test kits are much more reliable than the api kits.

 

[ihavtats29]

it was a free kit , but only 4 months old