Bob 10 should be ok but it would be nice if you can get 0.
As Franky says, unscrew all fliters and check they are all ok.
Take a reading of the water after RO only, if its coming out at 10 then the trouble is with the di vessel.
I had this prob a couple weeks back, it kept coming out at 13 after DI, stupid me screwed the cylinder the wrong way round ie it was upside down