Boise-Effective Feb. 1, major industrial customers like the J.R. Simplot Co.’s Don phosphate fertilizer plant west of Pocatello must pay a 5.62 percent increase in Idaho Power Co. electricity rates. The utility originally requested a 15 percent increase for industrial users, but the Idaho Public Utilities Commission on Jan. 30 trimmed Idaho Power’s rate increase request for five rate classes, which on average will see a 3.1 percent increase in their rates.