are you 100% sure your tds meter is correct, 7pmm, am 20ppm and that is in scotland, and i thought i had it good, any way no point getting rid of resin, as you said it last for years like mine keeps your water at 000 is assurance that if something goes wrong, at least you can not blame the water,and so look at brush contamination, and so on, better to be safe than sorry, you know the old saying, preperation makes a good job, and 000 tds is that to us in wfp, where are you based,