One more question: why so much ice water? Are you using it as bath to keep the mix cold?
Don't worry about the water. Just use as much as you want to just to make it easier to stuff in the casings. Nothing here is an exact science. Your bound to make mistakes and will learn about how much water, which spices you like, how spicy you like it. Its all in the learning curve. This recipe is just the one I like. You can add or delete items to your liking. Nothing is written in stone.