The sample line was in the aquarium water and I disconnected the other end where it enters the KHD. I manually ran the dosing pump until I had water coming out. I then took the end that was in the aquarium water out of the water, put the opposite end that connects to the KHD into the graduated cylinder and then manually ran the dosing pump until all the water was out of the tube.when you emptied the tube of the doser head 1 for calibration , did you remove the tubes from the machine and emptied into the graduated cylinder , or did u just tell the doser to empty everything into the graduated cylinder , haven't gotten mines yet, just trying to understand better