nitrates phosphates redfiled ratio

Hi everybody, It’s been some time my nitrates are at zero and PO4 at 0,1-0,12 (Hanna checker). My tank is 75G sps dominant. I run a skimmer and an Ats. I wonder if the combination of the two is too much, as NO2 at zero is not considered advisable and I’m thinking to shut down the ats. But before...