There probably is a way but I don't know it. I wonder if there're any test kits you can buy? Filters are a great way to go; no waiting for the chemicals to do the job, no noxious tastes and no drinking 120 degree water. Short of a true test I guess the best tactic is probably to get the most reputable product and just give it a shot.
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“I'd rather have questions that cannot be answered than answers that can't be questioned.” —Richard Feynman