I'm very happy to hear that most of your corals made it!
I have very bad news for this tank...
It has columnaris...
So far, I've lost: 2 female bettas, 1 von rio[gonna be 3 total], and 2 gold wcmms[believed to be patient zeros].
Last for sure fm betta is hanging in, babies are NOT happy...dk what to do...tank's wq is fine, fish just started dying and I didn't realize till I saw the fungus on her mouth while she was floating[yes, she was a dead]:
I bought coppersafe and gonna buy a uv sterilizer shortly...
if neither option works, I'm done with FW animals besides bettas -- this tank will be tore down, bleached, left to dry and then set up as the new reef[it has a t5ho light and will have 724GPH[~13x turn over].