The American Civil Defense Association - PDF - rehydration forumlas http://www.tacda.org/pdf/tacda/medical_ ... ilings.pdfthree different forumlas. one for rehydration to quickly restore levels during sickness. one for maintenace. and one for exertion, during highly physical activities.
i like this one as it also contains morton lite salt for the potassium. this document
goes into the specifics as to what and whys. good one to learn from.