Not so great update, unfortunately- I lost the Gramma a couple days ago. He took a turn for the worst and was struggling to breathe. I did look at his gills immediately after he passed and they were pale white, so on par for the labored breathing. There's no way the QT tank wasn't aerated enough either, as I have two air stones and a small powerhead, plus daily water changes to bump up salinity & make sure ammonia didn't cause any issues. There was a small amount of ammonia in the QT since it wasn't cycled previously, but under 0.25 ppm. Was using Prime and stability to keep that low, and I'm sure the slight ammonia didn't help at all, but it shouldn't have been enough to make him completely unable to breathe... I got the salt up from 12ppt to 27ppt in the QT over 15 days, so not like I was raising it too quickly. No more than 2ppt per day (usually a little less), and I took some break days where I didn't raise it if he looked off, so I don't believe I shocked him.
In the DT, I turned down the filter so there aren't microbubbles everywhere now, but the clown and puffer are still obviously being bothered. Still flashing occasionally, and I saw the puffer puff up today which he does when his gills are bothered. Clown yawns occasionally as well. Both are still eating like pigs, and still no physical signs of anything on anyone (including the Gramma).
It's almost time for me to start raising the salinity in the DT now, but I can tell I'll still have whatever gill issue is going on. So I guess not flukes and not ich at this point. And still 0 ammonia in the DT.
I was looking at Brook, but there's no extra slime or anything on anyone and never was, even prior to meds or hypo. Maybe velvet? But I feel like that would have taken them out quicker, and even the Gramma never showed any spots or anything after I began raising salinity... The only issue seems to be that they can't breathe right and that isn't helping me narrow anything down
Maybe a bacterial gill infection? I'm just trying to have a planned course of action for once I get the salinity back up since this is still an issue. Any ideas on where to go next?