My tap TDS reading is about 60. Im currently just going through a DI which is taking it to 000. I think by doing this, I will need to change resin more often, but I have got a RO sat in the garage doing nothing, just incase I need it. (due to having to change resin to often)
Id say if your tap reading is 80 +, you should use a RO first, before going through a DI. (Others might disagree with me, Im new to the WFP game so will be happy to hear others thorghts)
Ive noticed that first cleans do dislodge bits of dirt in the frames that you would never get to using the traditional methods, so if your results were poor, maybe try again once or twice with the pole, and see if the results have improved.
James