I would crank up that temp to at least 30°C and ad salt. I can't tell what it is in the picture, but it is in the slime coat and that definetely helps.How do you all suggest I proceed?
Water changes are 30-50% or more every 3 days at the moment. Temp is at 77F
Plecos and salt are gambling, so maybe try to remove and treat him seperately, the other fish all can take it, and I would try to focus on them.
There is "science" behind salt and higher temps aswell, and you will find plenty to tell you how good and when it works, and when it doesnt, its just as proven. Rid Ich contains malachitgreen/copper, that will get rid of the Stingray aswell.I wouldn't mess with salt or any other treatments. There's science behind this stuff, and the formulation in Rid Ich or Ich-X is what is proven to actually work.
I personally treat Ich just with temps and tannins, and had no loss since.