Digital BW, The Print

Question to the group: Epson 9600. I get the ink low warning, pull the 
cart and weight 210g. I get the ink out (printing stops) at weight of 
208g. A full cart weights 384g and a totally empty cart weights 160g. I 
know I do not want to go TOO low to suck air or settlement out of 
bottom of cart but 40g of ink in the trash. Does anyone know how to 
override this "feature"?
Thanks,
Mark