Convert Grid You can add grid lines, alter the position of grid lines, or even create an entirely new grid for an existing model within Grid mode. The Convert Grid window has option buttons for selecting the status of cells outside the old grid and Retain Previous Grid, Cancel, and Convert buttons. The Retain Previous Grid command takes you back to Model mode without making any changes to the grid. The Cancel command takes you back to Grid mode where you can make further modifications to the grid. The Convert command takes you back to Model mode and transfers data from the old grid into the cells of the new grid. How Graphic Groundwater accomplishes the conversion depends on the type of data.