Real science isn't that hard....

One of the ways in which you can know or suspect that you are dealing with pseudoscience is that you encounter overly complicated or jargon-filled gobbledegook in place of clear and concise language. Nowhere is this more prevalent than in nutrition.
A particular area in which the food faddists and poorly educated "nutritionists" excel at the practice of obfuscation-for-fun-and PROFIT is in the area of fluid and electrolyte balance. If it were as complex as these quacks make it we wouldn't have evolved beyond the single cell stage.
We need about 3-4 liters of pure water each day, more if we are active. Our body will tell us if we are "dehydrated" or salt-and-water depleted and we just need to pay attention. "Dryness" of membranes, low urine output (less than a liter/24 hours), lightheadedness (especially with a change in body position) all MAY indicate we need more fluids. In order to hang on to free water and replenish the salt water that makes up our body fluid we need to take in a defined array of minerals, most of which are contained in a balanced diet. So-called "electrolyte drinks" need to be considered carefully, as they often contain too much of one thing or another--often glucose, which we need but which in excess brings in too many calories. It's not exactly "common sense" but it is pretty easy,
and if it costs a lot of money it's highly unlikely to have a positive cost/benefit.
Take it easy! Your body is your friend, not an enemy to be conquered.
Salt and water to taste!