Saturday evening my Trident Alkalinity began dropping like a rock after days of a nice steady pattern. I narrowed it down to the peristaltic tubing on the DOS I am using as a test for feeding my calcium reactor. It was failing to push out even 50% the necessary water. No surprise, it had about 1600 hours on it! So, yesterday I changed out the head cap and did a 16% water change with 10dKh new fresh saltwater. Here is the graph that tells the story.
This is why the Trident is so awesome. And for those who want to say (have said) "Hey, you don't need to measure Calcium so frequently, you can just test manually once a week and sync your dosing to your alkalinity consumption" - What if this was my calcium dosing pump? Sure, both with Alkalinity and Calcium one would find this problem at the next infrequent test. But then you would fix the problem and have to do numerous retests to bring the tank back into stasis and then it would take the tank days to get back into full rhythm. If you can test all three with regularity, why wouldn't you want to?