Each soap recipe needs an exact amount of Lye in order for it to turn into soap. The suggested water amount is used to dissolve your lye in, and to help incorporate the lye evenly into the oils. When your soap is fully cured, the lye water fully evaporates and is no longer and active ingredient. People usually discount water so it will speed up cure time, and allows your batch to set up quicker so you can cut it easier and use it sooner. I usually do a 30% lye solution (when using the soap calc), I believe the soap calc defaults to a 26% lye solution, but you can change it. This percentage is telling you how strong your lye water is, 26% lye to 74% water. The less water you use, the higher the lye percentage goes. But your actual lye amount never increases, only the water decreases. If going by the MMS lye calculator, I usually use the middle range of water they suggest. Some people have done a 33% solution or use even less water, but with my recipe, it traces too fast and doesn’t give me enough play time to mix colors and FOs.