hi all i noticed when i last changed the resin in the van the tds went up instead of down.i normally get 4-6 ppm out of ro and polish it with a di vessel in the van.but the tds went up to 1-12ppm on a new resin.when i say new it's still unused from a bag i purchased 2 1/2 years ago.Does resin has a time that has to be used? as this is the only bag of resin i used and was ok when i used first use to get 0 ppm all the time.