Yeah these instructions are totally bizarre.
Let's start with some basic formulas (based on the internet conversion chart supplied with the package instructions in the original post). We'll use these for the examples given.
0.25oz = 7.087g
0.50oz = 14.174g
1oz = 28.349g
2oz = 56.699g
Let's just bypass the Tablespoons for the moment and use only measurements in grams (mass weight).
Calculating both 400mg and 800mg solutions to figure out how many gallons a package will make.
Starting with the bad (package instructions):
400mg: 181g divided by 28.349g (1oz) = 6.38 gallons of solution per package
800mg: 181g divided by 56.699g (2oz) = 3.19 gallons of solution per package
What the package should read:
400mg dose = 1/2 Tbls (.25oz) per gallon of water
800mg dose = 1 Tbls (.5 oz) per gallon of water
Then the math works after you convert ounces to grams
400mg: 181g divided by 7.08g (1/4oz) = 25.53 gallons of solution per package
800mg: 181g divided by 14.174g (1/2oz) = 12.76 gallons of solution per package
I haven't worked that out in Tablespoons yet. Volume and Mass don't always mix and since the package instructions are wrong .
Of course you don't have to convert anything to grams ounces work to:
800mg: 6.4oz divided by .5oz = 12.8 gallons
Edited by Free Spirit - 11/18/15 at 3:11pm