Most drink mixes will make either 10 or 12 quarts, and for the purposes of turning this into a soda "syrup," a quart is close enough to a liter. The Sodamixes originally came with 500 ml of syrup to make 12 liters. If your mix makes 12 quarts, fill your empty Sodamix bottle with 500 ml of water. If your mix only makes 10 quarts, then fill the empty Sodamix bottle with 420 ml of water. Now add all of the mix packets to the water, put the cap on, and shake until it's all dissolved.