Today I was topping up my brute with RODI water and noticed my TDS netter went up to 1ppm before returning to zero.  I have the Vertex Puratek and have had the unit for approximately a year.  I’m just wondering if I should replace my DI resin? Should I replace the carbon block and prefilter as well?  I have read the RO membrane is good for a year, is this correct?  The DI resin is the original that came with the vertex unit and it appears that it is changing colors.  
I have attached a photo of the puratek and the DI chamber to assist in identifying if I should swap it out. 
 
