So basically they add up there error range plus the error range of whatever kits your testing against , so if there error range is 50 ppm and salifert error range is 50 Ppm , that’s 100 ppm it could be off therefore they close the ticket , game over , oh you paid $600 for this and it’s off 100 ppm oh that’s nice have a nice day! I’m sitting here begging the guy for help as he’s telling me he’s closing the ticket , if my problem persists to open another ticket, my blood is boiling !!!!! Furious!!!