Gaza , i used to use my spent resin in the black box , i just whack new resin in it now , it lasts way longer than just using it in the van mount , a bag of resin used to last me 1 month , the last bag i bought since using my filter at home was 23/09/05 , mind you i did have a bit of the previous bag left , so i reckon a bag is now lasting me around 4 months , not bad for DI only is it !
Rich P @ F