Salifert vs elos nitrate test kit

[Silverni2]

I finished a salifert nitrate test kit last week my nitrates were between 2-5ppm and have always been about that. Now that I have been using a new elos nitrate test kit I'm showing 0- 1ppm. I also have a skimmer that's about 3 weeks old and I'm finaly starting to break it in and a refugium that is maturing and I'm leaving lites on 24-7 over the past week. I guess I'm trying to figure out if my skimmer and fuge r doing there job or it's the test kit
thanks

 

[batt600]

To me elos was always more accurate then salifert. But thats my opinion.