You only need enough powder to change color -- it doesn't even have to be a dipper full.

BUT, the dipper quantity is MUCH less than 1/8 teaspoon. If you have some dry popsticks, and can whittle that down to about 1/4" wide, and then dip out enough to cover the tip of the stick, that should be more than enough.

However, you should call an request a new bottle. That dipper is a fairly critical item.

Regarding bleach dose: with a 30K gallon pool, your PF is 4, so each gallon of 6% bleach will add about 2 ppm. 10 gallons will add 20 ppm.