I flush when I re-fill after flushing for 25 mins flushed water comes out at 47.
Is that the reading While you flush or After? Assuming that it's the reading after finishing flushing, I dont think there's much you can do to reduce it, after all the tds has to go somewhere, and you'd rather have it going out through the waste than through your pure water!!
Does your tds change on the pure side of your ro, that is Before your di, if you have a di vessel?
Tim