Well i got chuck's calculator and got that I should add 27 tbsp's to 1 liter of water to make it so 1 ml will give me 1ppm nitrAte in my 72 gallon. I did this and not all the fertalizer dissolved.. what is up? does it jsut take along time? 

yww that was myt next thign to try...And if that doesn't work then:
a) Add 27 tablespoons to 2l of water and dose 2ml for 1ppm