Hi i am using two di vessels at the moment, Just had to change my first one as my tds went to 2 .It was pulling it from 90 to 50 then the second from 50 to 2 .Would there be much of a benefit in getting a third one ??? so it would be from say 90 to 50 to 2 to 0 .As its seem a waste to throw out resin that still has a bit of life in it still . hope you understand what I'm getting as , Cheers G