Is this caused by my eel or HLLE?

[HAAAAAAAA]

Yeah the 3 eels I have are good with my tangs. My sailfin actually tries to bully my jeweled eel when he goes in his cave. But otherwise they get along no issues. I just wait until they are big enough to go in. I have a baby (tiny) Atlantic blue tang who is about the size of a quarter not including fins but she is in my coral tank until shes big enough that they wouldnt try to eat her.

That is a good suggestion! The grouper in my tank which is about 10 inches and fat just sits beside my fangtooth but even so I still do sometimes see some scars on the grouper

I've learned that with these wild animals there's just no certainty, they may get along fine for even a year but suddenly just bite back