One tablespoonful (3 tesapoonsful) per gallon of water is the ratio that is needed--whatever amount you want to give your hen in a day is fine. If she drinks a quart a day, use 1/4 of a tablespoonful. The next day if she drinks less that that, mix 1/8 of a tablespoonful per pint. Chickens will drink more in hot weather than in winter, so the dosage will vary during times of year. Also, sick chickens will not drink well usually, so oral dosing may work better.What I can't figure out is how to get the right amount for A chicken?! My hen certainly isn't going to drink a gallon of medicated water 2x daily. Am I missing something here or does this info seem to be all about treating a flock rather than a single sick chicken? I suppose you could just do the math for a lesser amount of water but also how are you all measuring by the mg?