Recently i bought a new membrane for my RO/DI filter, as well as a TDS meter. I disconnected the Resin chamber, inserted the new membrane and flushed it for around an hour or so. I then tested the water which was coming out and it gave me a 0ppm reading. I then connected the Resin chamber and started filling a drum, which i filled halfway. When i tested the water in the drum , it gave me a 14ppm reading... What would be the cause of this, is it perhaps something to do with the resin, or maybe the drum i used was not rinsed and still had some salt/dirt inside?