An ink jet printer includes an ink feed apparatus. The ink feed apparatus includes an ink feed channel for conducting discrete substantially solid ink sticks along a feed channel path, a plurality of ink sticks in the ink feed channel, each of the ink sticks comprising an ink stick body having an ink stick sensing feature on an external surface of the ink stick body that is located between a first end and a second end of the ink stick body, and each of the ink stick bodies has substantially the same mass as the other ink stick bodies in the plurality, a detector positioned at a fixed position proximate the ink feed channel and configured to be triggered by an ink stick sensing feature on an ink stick in the ink feed channel as the ink stick moves along the ink feed path past the detector, and a counter configured to accumulate the number of times the detector is triggered.