Okay, you need between 400 and 800 mg.....
400 mg=0.014109585 Oz=.085 tsp
800 mg=0.02821917 Oz=.169 tsp
So, lets take these numbers and see if we can get close to a few of the standard measuring spoons see how much to put in......
1/16 of a tsp = .0625
1/8 of a tsp = .125
1/4 of a tsp = .25...