Line two baking sheets with parchment or waxed paper.
Combine the water and sugar in a large nonstick heavy-bottomed saucepan over medium-high heat. Stir to dissolve the sugar, 4 to 5 minutes. Add the corn syrup, cane syrup, and salt, and stir constantly and slowly with a wooden spoon until the mixture comes to a gentle boil, about 12 minutes. Continue stirring until the mixture reaches between 225 and 230ºF on a candy thermometer.
Add the nuts and continue stirring until the mixture reaches 290ºF. Remove the pan from the heat. Add the butter and baking soda and stir until the butter is completely melted, about 1 minute. Pour the mixture onto the baking sheets, being careful as it is very hot, and spread evenly with rubber spatula. Let cool completely.
Break into pieces and store in an airtight container. Will keep for up to 2 weeks.
Yield: 4 pounds