Here is our approach to mashing:
On the recipe page, enter temperatures, times, and rough amounts. The fields are all optional. From there, save the recipe, then click the 'brew' button. The system then uses your equipment profile to figure out exactly how much water your will need for the mash. (You can setup your equipment profile under the gear icon in the upper right.) Then go into the brew feature's Mash Calculator tab. From there you can adjust the mash ratio, grain temp, mash temp, and do infusions, etc. It saves every detail along the way. It also helps zero in on the target water volume for the brew.