The benefits of regular testing
 

Had this happened 6 months ago, my tank would have been toast.

I noticed one of my stags was starting to STN up from the base for no reason, so I did a water change a few days ahead of schedule and collected a water sample, but I didn't have time to test it so I put it in the fridge for a couple of days until my "normal" tank maintenance day.

dKH: 4.4

A quick examination of my dosing unit revealed that the airline tubing I use to bring the alk up from the container to the peristaltic pump had cracked where it slipped over the pump's connector nipple thingy, so there was no suction. It must have happened last week when I was re-progamming one of the pumps.

I replaced it, but thank goodness for a routine testing schedule or I'd have lost every coral in the tank.

I agree.
Sometimes the outlets of my dosing tubes plug up and nothing gets into the tank.

Haleluyah, brother! My Alk line occasionally plugs up at the outlet. Now I know to check it regularly. Another time one of the peristaltic dosing pumps was coming on, but the rotor wasn't turning. I had to take it apart, re-jig it and put it back together, then it worked fine. Etc, etc. You don't catch these accidents unless you test your params regularly....