For a reef fishtank, is it better to use old RODI filters or plain tap water?

My reef store is out of filters for my RODI unit right now and I really need to do a water change. My TDS meter is reading 0 ppm going into the Meyer, but 11 ppm comming out of the meter, which I believe means that most of my filters are good but the last stage filter must be bad. How bad is a TDS reading of 11?... show more My reef store is out of filters for my RODI unit right now and I really need to do a water change. My TDS meter is reading 0 ppm going into the Meyer, but 11 ppm comming out of the meter, which I believe means that most of my filters are good but the last stage filter must be bad.

How bad is a TDS reading of 11? I have spa, LPs, and soft corals. Oh and I am filtering well water.
3 answers 3