[EandM]

http://www.pistonheads.com/gassing/topic.asp?h=0&f=10&t=1534091&mid=404476&nmt=bought+a+resin+vessel+online%2C+returned+it+now+they+wont+

[Smurf]

You plonker rodney springs to mind 
Sounds like the chap who brought it don't have a clue how a di tank works as if he had tested the ppm coming out of it would have know he had connected it up the wrong way.  Also most have the inlet & outlet marked up or at least and arrow to indicate the correct flow.  Not to mention having it connected up the wrong way will force the resin out so will be visable on whatever he is washing too.