need help reading Salifert nitrate kit/pictures

[rmcouvi]

Do you rinse the frozen cubes or do you just put them in the tank still frozen? If you don't rinse the food first, the liquid that the food is frozen in has very high nitrates.

 

[Angels 2010]

I agree with rinsing frozen foods, the level of no3 and po4 can affect your tank levels, but I don't feel that the no3 is all that high and your po4 will be affected greater than your no3

 

[Joezreef]

looks like I may have a defective kit>> I just measured the n03 of my water change water and it was darker than the water form the tank?(reefcrystals) It says on the top of the box 1/2010? what does this mean...whats the chances of me getting a bad kit?