However,in yesterday,I found that one of his gill was injured,like the following photo:

Therefore,I used the Bacterioses and Fungi Pinnarum for four of them together,while the other three was OK.
Today,another one keep on open his mouth.Just now,the others was doing this also.Like the following photos:


What happen to my fishes?What should I do for them now?
I am only a little guy from Hong Kong,please forgive to my poor english.And I hope you would understand what I am talking about.