One of my Oscars skin in coming off and I just did a water change yesterday !! And. It's got worse??? Today!!! What do I do its a 60 gallon tank?? 3 filters and one round bubbler!!!
Fins don't look torn to me, they look to be deteriorating from poor water quality. Which is probably the cause of the skin condition as well. Tank is small for this fish, so without exceptional maintenance water quality can easily slip.
How often do you do water changes on this tank, how large are the changes, do you test your water and if so what are parameters for nitrite, nitrate, ammonia?
Looks like another Oscar is biting its side, his pectoral fins are ripped up also. I had a couple Ocars that did that when I wasn't around. I spied on em one day and seen the bigger one kind of like punching the other in the side with his mouth leaving a ton of scales missing. your water does look a little cloudy but if your parameters were that far off to burn him that bad he would probably be a bit lethargic. More info on tank and tank mates will help a lot.
One of my Oscars skin in coming off and I just did a water change yesterday !! And. It's got worse??? Today!!! What do I do its a 60 gallon tank?? 3 filters and one round bubbler!!!
Assuming you only have two oscars and they are both in the same tank,that gives each Oscar 30 gallons. Probably less with water displacement from gravel,rocks etc.
Whatever the issue is with your oscars side I can not say for sure but I will assume it is a water quality issue that is the route of the problem.
To properly maintain 1 adult Oscar healthily in 60 gallons takes dedication, two or more I believe will ultimately suffer.
I don't mean to be negative but I would find smaller fish to keep in your tank,two or more?will be very cramped and restricted in your current set up.
I agree with stanzzzz7, a 60 gal tank is too small for just 1 oscar, much less 2.
So it could be a combination of all the above reactions to your post.
With 2 oscars in a 60 gal tank, you should be changing a significant amount of water every day, no matter what the amount of filtration to keep them healthy(at least 40%, as long as you keep them in that tank). They are swimming in fish urine soup now.