I posted a few months back about electrolytes and being chronically depleted bythe end of summer. I got several great recommendations. I ended up with generic electrolyte tabs found at: www.readykor.com/medicine/electrolytes. The tabs have 250mg of sodium, 15mg of potassium and 18 mg of calcium carbonate. Two tabs come to a pack. The final regiment that works best for me is to take a pack the night before I ride, one that morning and then one every hour. I drink only water and may use a cliff gel per hour as needed. Also I avoid caffiene(sp) the day I ride. This has really helped and I highly recommend it to anyone who has problems with dehydration.