Ever since owning our pup which we bought in the spring, and had antifreeze in the plumbing from the dealer (used), cycling water through the system I wind up able to drink nice clean water after a few cycles. Then it sits without any changes, and the next day the first couple cups of water from the sink not only tastes and smells of antifreeze but it literally has a pink hue to it, and it fizzes like it's carbonated. I've flushed the tank with bleach water twice now, this year. I've ran probably 15 gallons through the tap. When I last winterized last fall (same the year before) I never added it to the tank, just unscrewed the pump feed line and pumped maybe a quart or so into the pump and lines. To my knowledge the tank has never itself had antifreeze in it, as the tank when we received the pup from the deal initially was clean looking, not pink, etc. I don't understand how this can be. Like sure maybe some antifreeze might sit in some dip in the line somewhere and occasionally water fills the line solidly enough that it pulls some up with it. But like it's cups worth that are wholly undrinkable, and then maybe a few gallons of constant running the tap before we can no longer taste anti freeze. Only to have it return the next morning like nothing changed! I was thinking hell I'll just replace all the lines and that's GOT to do it...but then of course those lines are all gooped into place at every point that it goes through walls etc. ugh... Any advice?