You can know your tank as well as you think you want to. But when you think you're having issues with a coral, and you tell me you don't test an important parameter like alk...that's gg.
The FIRST thing you do when you see anything wrong with a coral is test everything...it doesn't bother the coral, and eliminates that issue.
How are we or anyone supposed to say if something is wrong or not. A picture? I'm not gonna blow smoke. Picture looks fine to me, even under so much blue. Whether it is or isn't who knows. Do you know what happens to your parameters on day to day?
If you don't, you don't know your tank that well, and if you don't, nobody does. I'm not gonna sugar coat anything and I'm giving it like it is. Harsh or not.
For example, like clock work i can tell you
One day my alk is 163, with cal 485ish, mag 1350.
Then I can usually expect to see alk 161, 485, mag 1320 the next day.
For some reason it goes back and forth like that. It could be the test itself, but that's 7 days of testing it and 2 months of testing almost everyday.