"Pete" wrote:
My blend doesn't say anything
I bought it from www.homebrew.com
There website doesn't say anything either.

Assume .15 then.

Looks like 5.85 teaspons per carboy

Or six. ;-)

I will add this tonight

I guess I should take another reading tomorow?

If you plan to take another reading, why not add 1/2 the acid now, and see
how that affects the measurement. Then you will know if your calculations
are good, and whether the acid is .12 or .15 tsps per gallon. (The
difference will be whether or not it is powder or granules, and the
percentages of each acid in the blend). And you won't add to much if there
is a (small) mistake in your calculations. You can take the second reading
after you've stirred the acid into the must. You don't have to wait until
tomorrow.