I use Pedialyte and Liquid IV. At work (I’m a firefighter) I use them daily in the summer. I limit myself to one or at most two servings, spread throughout the day.
I have heard stories of people getting messed up from drinking too much of this stuff. Last year, a Captain from a neighboring department told me one of her firefighters developed a messed up heart rhythm after drinking nothing but Pedialyte for 24 hours. Seemed like a dumb idea to drink nothing but Pedialyte anyway.
Fast forward to a few months ago I was talking to a Doctor who works with one of the regional Urban Search and Rescue teams, and he said one of his guys got messed up in Miami at the apartment building collapse from drinking nothing but Liquid IV. I asked him about the intelligence of drinking nothing but electrolyte replacement drinks, he said it was so hot that guys were drinking a gallon and a half of fluids a day and still only urinating once every 24 hours. He said they switched to DripDrop and cut the dose in half, and nobody else had ill effects but thought any of those drinks would probably have negative effects if that’s all you drank.