I had no idea about that, but some cursory Googling seems to indicate this property is only really true of fully purified water - either via distillation or tur

I had no idea about that, but some cursory Googling seems to indicate this property is only really true of fully purified water - either via distillation or turning it into steam first. I suspect that all but the most impressive water filters are still going to give you conductive water, but regardless it’s an easy thing to test.