The package weighs 40 grams and the label says it will make 250 gallons medicated at 64mg, so it's 40 grams divided by 250 gallons = 0.16 grams per gallon. One teaspoon probably weighs 2.5 to 3.3 grams. It's your lucky day, 'cause I happen to have a pack of this that I acquired for my powder weighing experiment, so I will go weigh some. Best guess is that the per gallon dose will be about 1/16 teaspoon per gallon, but I'll go weigh it right now.
40 g in 250 gal is indeed 0.16 g/gal, but that's 160 mg, not 64 mg, so something is not adding up.
2.5 to 3.3 grams is a 33% difference! That's a large error to be working with, but it probably won't make any difference in the end unless it's a very powerful med.
It's not adding up because there are only 16 grams of lincomycin in that 40 grams. Just weighed it, and it's much denser than the other powders that I've weighed, it's 3.6 grams per teaspoon.
Edited by casportpony - 2/18/16 at 11:03am