Are you reading zero after your RO or after your DI? If the DI isn't spent, your output will always read zero. The risk is you may be using up the DI resin faster. You should try moving your sensors around and see what differences it might make for you.
Also not all membranes are created equal. The one I had before this one was awesome and never read above 10 (until it died). This one I have now has terrible TDS creep. I kept my old one so I know what brand to look for when this one is done.
Whether I put it somewhere where I can find it is a totally different matter but has nothing to do with YOUR thread here so I'll stop typing now.
