Totally agree with using God given senses, but if you are thirsty logic might get compromised? This is one reason I like to use Chlorine on questionable water. Put in what is thought to be a appropriate amount shake and leave set. In 30 min to over night pop the cap and if you don’t smell chlorine (the swimming pool smell) do it again. If it smells strong chlorine pour it back and forth between two clean containers until it vapors off. No scientific testing technique just poke your nose into it. Carefully of course.