The worst was/is yet to come
Whatever is going on with our water parameters, it seems that the serpent star deaths were just the beginning. I did a water change yesterday and 40 minutes later, all the inverts and my flame angel were dieing. This evening we pulled out every snail, crab, starfish, queen conch that we had. all dead. The flame angel had looked like it might pull through, but did not. The naso tang died the day before, the rabbitfish and lawnmower blennie started swimming at top speed, crashing into things, the rabbit cleared the tank but is now back in it and sorta ok. The lawnmower blennie got moved to a 10 gallon quarantine tank.
I am sure that the creatures that died overnight, did not help the situation any, but we think we have gotten them all out of the tank.
All in all, so far, forgetting emotional attachment, we have lost about 300.00 in inverts and fish.