I purchased a Watts ZRO-4 on ebay and the label on the Aquatec pump shows the pump was manufactured on 3/27/03. Everything is new and still factory sealed though the box shows its age from warehouse storage.
I am assuming that the RO membrane in this system must be at least 5 years old. Do dry membranes have a shelf life for this long? Would it be safer just to replace the membrane? Does Filtersfast sell this one? Any help on this one greatly appreciated.