Funny not funny. I just had this issue with my calcium. I got woken up to “calcium is 750.” I ran out to see a snowstorm and my tank looked normal. All other parameters were normal aside from a schism on the graph where magnesium suddenly dipped and calcium suddenly spiked.
Step 1: What’s your PH? Did it rise with your new high Alk? If it didn’t, it’s a trident error. Still do step 2.
Step 2: Test alkalinity. If it’s really that high I imagine your tank is in bad shape. If it’s normal. Move to step 3. If it’s not, begin the ancient dance of the major water change!
Step 3: Make sure the needle for your testing solution is sitting correctly in the container and the line isn’t pinched. Make sure the needle and hose are tightly on the 90deg elbow at the lid.
Step 4: Open up the little front gray cover above the reagent tray. Look at the cuvette with a flashlight. Does it look dirty? If yes, google how to clean it. It’s easy. This needs to be done every 6 months anyway.
Step 5: While it’s open, note the small circular device at the back of the machine with all the hoses going in and out. Each one has a small actuator that pinches the lines closed or opens them depending on the test. Make sure each button is pinching and releasing correctly. You can manually press each button to make sure it’s working.
Step 6: Clean your sample line by unplugging it and forcing water through it.
Step 7: Re-prime everything and run a test with the drawer open so you can confirm nothing is pinched.
I did all of this, reset and re-set it up, and it still gave insanely high calcium. I had to replace it.