Dude, your kidneys don't excrete a liter per hour, that would be 24 liters or more than six GALLONS per day. More like a deciliter. And just seasoning your food with some sea salt will deal with the electrolyte loss just fine, no need to buy little baggies of chemicals from anyone.
Sorry, should have been more clear. They are only capable of excreting a liter or so an hour. So your intake/output levels need to be balanced otherwise you are diluting your salt balance.
