Oh man, so sorry this is happening still Nate.
What I will suggest is going to be extreme so only do if you are ready.
Both you and Jason keep a much more "mixed" reef than I do.
I only keep montis and birds nests for sps. My wife hates the sticks haha
So I don't get all the coral warfare as much.
When all those new imports came in with bacteria and spread through the Hobby like wild fire, it was hard not to be a part of the carnage. That's probably where you got 1st introduced with the bacteria. Hard to pinpoint the exact time.
On top of that bacteria, you have a ton of coral warfare going on that you already know about. You have a gorgeous tank, but all that stuff has been added fairly fast over the last year or so.
You're trying to control all of that with carbon and other means of mechanical/chemical filtration....so that adds to the inconsistency of the tank.
You know this, but it's just part of the hobby lol
I know you know clams so this info is probably redundant lol
The clam could be a good indicator but also watch it's shell to make sure it's always white and growing. As you know the mantles should look like a flowing curtain, not just a small window covering.
As you said the clam is a good indicator and it will show some signs of being sick like staying shut, keeping mantle small and no growth on shell . If it has zero new white shell growth that is also a sign it is really not doing well. It will still open but then 1 day just melt in the shell. They are finicky buggers as you know! So if he doesn't want to open and does for a day or 2 , that shows that water is probably still harsh for it.
Ok so now to what I would do....and take this with a grain of salt as we all run our tanks differently.
You have established a certain type of eco system in your tank. Right now, it's naturally trying to go in 1 direction, and you are trying to "dose" or "clean" it into a totally different direction....You will never win this battle unfortunately unless you got POLOreef type of money and can basically just flush seawater through it daily lol. I'm exaggerating but you need to flush your system completely of the bacteria. That's almost impossible so we have to let it "die" off.
If you can, Let your tank go all natural....think of
@fishguy242 and his tank. But on your own level of comfort.
Stop dosing anything but alk, cal, and Mag to maintain stability in numbers.
Try to only use your skimmer and sock/filter roller.
Let the coral die that has to die due to infection and pull it out on the 1st sign of losing it.
Don't worry, down below I have another method that allows a different approach.
Unfortunately, the torches get bacteria into the skeleton, and it's so microscopic that it eventually reaches every head. Some take months to do, but it eventually happens. Even with cutting off bad heads.
The hardest thing to do is to stop adding anything new for at least 6 months to a year.
If you really want to get control of your tank, you gotta stop bringing in outside contamination.
With all that being said, I know it's not that easy.
So where to start....
If you don't want to, just let stuff die, which I completely understand!
I'd do weekly baths in cipro for all torches in a separate tub. 24, 48, or 72-hour baths. I was comfortable with 72-hour baths, but make sure the tub is set up for it with heater, powerhead low low flow just enough to move water and airstone.
Make this into a larger batch, but here's the sauce.
In a 1g tank water bath, I would use 250mg cipro and amoxicillin 250mg. Crush and dissolve
I also add restore 10ml, microbac7 10ml coral amino acid 10ml , with hazel 10ml.
Toward the last 4 or so hours, I add Iodine until the water turns brown/tea color.
repeat weekly or just give the torch as much time back in the tank as you did the bath for and then repeat.
At the same time, cipro the tank full dose.
Keep doing this, and you might pull them through and clear the tank.
It gets costly and monotonous but keep at it and you should see some change...in theory of course. Nature is never a sure thing.
It's seriously like a job haha
Definitely good luck!!!