So, I was removing my 2 membranes for the season and believe I have the O-rings in the right way, but when I pulled one of the membranes up and out of the 4" housing where the O-ring was at the bottom where the inlet is, there was some really stinky water/sap left in the space between the housing and membrane? I did a wash, rinse, acid and let sit for few days. Then did another wash and rinse.

So, wondering why the stinky water was still in this space? It only seemed to be outside the membrane and not inside it. Does this area not process the sap when it is running? I have the O-rings facing the inlet with the wide shoulder facing the same. I thought this was supposed to stop any sap from getting around the membrane. Maybe I have a leaky membrane? The other that had the O-ring at the other end seemed fine. Maybe with the o-ring at the bottom, it can't drain out? It was a few weeks after we pulled taps before I got to this, but I had done a wash and rinse after we got done.

Any insight?

Thanks