I dont have micro weight, but took a 1 gram vit c capsule and emptied it in a tea spoon. All are approx measures as spoons are different sized. I wouldnt worry about the dosage; I did overdose borax on purpose just for a test a couple of years ago. If I only have learned to keep these posts at hand ..
But as far as I remember I took 6 full 00 capsules a day, approx 6 grams of borax daily for 10 days.
Side effect was a dry, crusty nose and dry skin. When I discontinued these symptoms was gone in 2-3 days.