add a bit of salt to your tap water - it helps to retain water and doesn't flush out your deposits.
too much water and too much salt are both bad! had a dude in my village die after drinking around 5 liters on a dare - nervous system failure. it was so severe that he couldn't be saved.
Take a half full water bottle. Add some salt. See if it is salty yet, then keep adding until it is just barely salty. Then fill the bottle to the top. If you taste salt you added too much.
Note that with kcl, you start with less water, more like a quarter of the bottle, because the salty flavor is much weaker.
Basically I don't consume sugar or alt-sugars so I make my own version of gatorade.
Start by making sure you're eating enough. Adequate salt quantity starts by getting it from your food and getting enough to eat. Second just (slowly) add small amounts to your food and see if that addresses the problem. If you're exercising or doing physical activities and sweating a lot while also drinking a lot of water, you likely need to add some salt to food. As others have said, it should not be such an amount that tastes overly salty. Start really small.