I guess I spoke too soon. This morning I took a KH measure and got 9.2 which was 2 higher than any previous readings. I quickly pulled my other test kit and came back with a 7.5 reading which was in the ball park of the KHD as of midnight. I reran the KHD again and got an 8.3 reading and then remeasured and recalibrated the sample tubing. Then I renan the measurements 3 more times and now am at 8.7. So I'm not sure what is going on. Some differences I'm seeing:
- I am now getting the 10ml in the initial waste and the waste tubing remains full. Before, I was getting only 8ml and the tube was completely empty be the end of the initial waste
- By moving the sample tube to the display, I can now see that the clearing of the tube for a the next sample doesn't completely clear there is about 2ml still in the tubing. If I remove the tubing from the water whil it clears, it all comes out.

Please help. I want to be able to trust these readings...

Something to note, is that this is an AIO tank and doesn't have a sump, so sample tubing runs 6 feet to the tank and goes about 6 inches into the tank. I started dosing Triton which should increase KH, but have seen only about a .2 increase in KH since starting dosing from Saturday. I also did a 10% water change on Sunday which didn't increase KH, it was still at a steady 7.