When we had the outbreak, I quickly searched here on BYC and found the common ratios were Dawg's and others who said 1/3 teaspoon per gallon. I saw some search quotes that said 1/4 teaspoon per gallon and a couple that said 1/2 teaspoon per gallon. This was for the 20% powder, btw.
I said "Bah!" All I knew is chicks were dying and the precise formula wasn't important to me. I realized that there isn't THAT much difference in any of them. I didn't have time to sweat the details. Close enough for hand grenades and horseshoes.
It saved the rest of the chicks virtually within hours. Within days they were completely normal. That's is what was important to me. What I learned? Even after 50 years of husbandry? I'll never ever put chicks on the ground without it. These birds we have now are not $2 feed store chicks. They are priceless.
Others can do what they wish. I know precisely what I shall do in the future. I learned a painful but important lesson.
Best regards.