There is one unit of syrup for every six units of water. Therefore, 1/7 of the mixture will be syrup and 6/7 will be water.
With 4564 milliliters, there will thus be 652 milliliters of syrup and 3912 milliliters of water.
The difference between these is 3260 milliliters, so 3260 more milliliters of water will be used than syrup.