I just got a BRS 4 stage rodi system this past friday. I let it run for an hour pouring the good and bad water down the drain like they said to do. Already made 5 gallons of good water today and making my 2nd 5 gallons. I noticed the far left filter is brown now. Whats this mean? I am on a well that is prefiltered. Also i tested the good water with a portable tds meter i got from awi. It reads 41. But the inline tds meter reads 0 for the output. Help!