Unfortunately Dr. Joseph Mercola is spreading a great deal of bad information to his audience about water filtration. Whoever he is consulting with is giving him old and bad information. I suggest you ignore everything he says about water.
Also…the systems he sells are junk and do not perform as claimed. Mercola’s Pure and Clear Whole House Water Filter does not perform as claimed. If you want to see the best whole house water filter, then check out my Urban Defender.
Dr. Mercola, if you’d like to do a better job with water issues, I invite you to call me. I give you credit and presume that you do not know the information you’re spreading is wrong. I’d be glad to speak with you.