I use as seasoning kelp on salads about each day for 4 months. Just guessing I use less then a teaspoon at a time. I use it out of a salt shaker
I did find this article on Kelp and how much
Nutrition Diva : Is Seaweed Good For You? :: Quick and Dirty Tips ™
"A serving or two per day of seaweed won’t cause a problem for most people. But just to be on the safe side, I suggest avoid eating large amounts of seaweed every single day, particularly kombu or hijiki, which are particularly high in iodine. Dried kelp granules, which are often sold as a salt substitute, are also a potent source of iodine. A quarter teaspoon can provide two or three times the suggested upper limit for iodine intake, so you don’t want to overdo that either."