Am I undertstanding this correctly from the QC doc? (1/2l of vinegar per 10 kg of sugar against nosema)

They are saying to add 1/2 litre (just over 1 pint) of vinegar in addition to the water (approx 7 quarts) to 22lb sugar to make a 2:1 syrup mix ??
Sound like an awful lot of vinegar, maybe my math is wrong.