Dying fish, lots of details, please read.

[Octoberfest]

When there is a velvet or brook outbreak doesn't it usually go through all the fish, or at least most of them? Especially if the two clowns are constantly next to each other?

Only reason I'm asking is I would think if it was either brook or velvet that killed the other two fish that at least one of the remaining fish would be showing signs or dead by now.

 

[Floowid]

How long were the clown and angel together before this happened? Disease likes stressed fish, and by your description, the angel and the larger clown may have been trying to establish a pecking order, or the clown (if it is anything like my large female clown) could have been striking out at the angel any time it came near her anemone, which would be all the time in a 60 gallon tank. It may have been brook or velvet, and it may have only affected the two fish who were stressed and weakened from continual skirmishes. Just a theory.