I just got a couple liters of neutral saline drip [I keep them around for using as an emergency eye wash here on the farm] and was wondering other than the taste, would they keep one alive if you didn’t have regular water available to drink? [sort of a locked in a vault scenario]
In a similar question, could you stretch the available water supply in a lifeboat by adding salt water to the pure water supply until it is at the same concentration as neutral saline?
If by “neutral” you mean isotonic, then sure. It’s basically Gatorade, you could survive on it indefinitely.
Yeah, sure. Once again, you are basically creating Gatorade.
You could, of course, dilute it much less than that and survive on it indefinitely. Humans kidneys can handle surprisingly brackish water provided we have enough food to eat. We’ve had several past threads on how little you can dilute seawater and still survive, and nobody seems to know the answer. The idea of mixing one part saltwater with three, or even two, parts fresh water part seems reasonably sound.