I did test for PO4 and it was at 0.00 and that was using a Hanna colorimeter. Did not test for NO3 but will on the next batch I make up. BTW the salt that I am using is the Tropic Marin Pro.

How do you like the Hanna Colorimeter?

It's a bit finicky to use but once you get the hang of it not too bad. You just have to be very careful not to let any foreign material into the little curvette reader thingy (that's technical talk for all my fellow geeks). Definately scares me that I was taking the word of my Salifert PO4 test kit as I got multiple higher readings using the Hanna.