Nothing yet, but this is what I've done so far and what's happening today:
I took the leather out and put it in a holding tank (last night). It started to look better but I'm not taking any chances. If I could measure for terpenoids, I'm sure the tank was over it's limit. I put the kick-ich off temporarily (decided to double-dose garlic in the meantime, the fish look a little better) and started running carbon last night. I moved the digi out of the direct blast of a powerhead (which I heard they don't like) and placed it lower in the tank by about 3". It was starting to 'fuzz' this morning (through the magnifying glass

, kind of looks promising). I moved the pink poci lower also but still nothing.
I'm installing two check valves today which means I need to empty about half the tank, and while I'm at it will do a good water change. I realized that I've only done one (about 2 gallons) since the new tank was set up exactly a month ago; and with that leather not doing well, the 'kicking and screaming' it's been doing was not a good thing. Going to check all parameters after the change.
Interesting, though, the monti cap is doing excellent. And, now that I think of it, the poci did show some polyp extention when I first put it in the tank.....hmmm. So it's more likely the water.
I have one more thing to check, on a hunch, and will post that later.
Sorry this is so long, but with all of the issues going on, I'll look back on this thread some day knowing I've learned a hard lesson.....
Thanks for 'hanging' in there with me!
Well now I feel like an idiot, just found out my water temp was at 78 and not 80! Good grief.....I'm sure that didn't help!!!!!