tds meter

So I have a inline TDS meter hooked up to my RO unit which is then hooked up to an auto topoff float valve to the tank. My question is...in order to get a proper reading from my TDS meter does the output flow have to be fast? It seems as though if I decide to fill a bucket with fresh RO my readings seem to be at 0 or 1. When I just allow it to topoff the readings are around 711. It doesn't make much sense. The topoff is fairly new, same thing goes for all of my filters. Any toughts?

Since R/o units are not running continuous. as they set the water in the canisters becomes degraded and as the life of the filter medium depletes the degrading becomes even more pronounced for the water that 1st comes out of the filter after sitting for a day or more. The water in the filter that was left when the filter shut off needs to be discarded 1st and then only fresh water just filtered used. one way to do this is to fill up a large sump or container with makeup water and use that for make up. run the r/o for 10 minutes and discard all output before using. there are several ways to approach this, just make sure you discard enough water initially to completely cycle the filters before adding to your system. hope this helps.