I bought a 4oz package of Durvet High Performance Poultry Pak (vitamins and electrolyte supplements). The instructions on the package were for an automatic watering system. So, I emailed Durvet and asked them how to dose a small flock using a waterer for chicks. They told me to use one teaspoonful to 5 gallons of water. I am using 1 quart waterers so, I just made it simple and I am using a quarter teaspoon.
I just thought I would share that info in case anyone else had that question.