Yesterday I winterized a house. I had several jugs of RV anti freeze that I introduced into p-traps and when I poured it into the toilets I noticed the pink anti freeze turned bright yellow. I noticed today it was clear again. whiskey tango foxtrot! Ever seen this before? Its artesian well. The house next door on the same well didn't do it. There is no water softener..I didnt see any tank bowl tablets. I'm baffled.