Anyone familiar with seawater knows it is not acidic, nor anywhere close. Similarly, inland dry lakes (places like mono, great salt lake, salton etc) are not acidic. But the ph is not relevant to why they can't sustain life. Its a lot more complicated than that.
No, the water in the above examples will not sustain life if you put 'acid' in it to neutralize tested ph. The real core of the issue is the disolved mineral content of the water and how healty or not that is. That ph correlation is neither fundamental nor fully reliable. Its a gross oversimplification.
The fact specific exercise is: not {all acids} introduced into {all alkaline solutions} make for end-state simple (ie, potable) water. The result is often, water with residual mineral content. And often that is, in fact, quite toxic. EG,
Another definition of a basic salt would be a salt that contains amounts of both hydroxide and other anions. White lead is an example. It is basic lead carbonate, or lead carbonate hydroxide. These salts are insoluble and are obtained through precipitation reactions.