Hi, I'm new to the forum but I've had tropicals for all my life off and on (40yrs). I never had health issues with oscars before,they always were hardy. Recently I had a bout with Ich in my tank and treated successfully with Aquari-sol which worked great. But I noticed that since I've treated the tank one of my Oscars has acted very different. He sulks on the bottom of the tank with his fins clamped. He eats fine and is the first one to the top of the tank when i approach but then he immediately goes back to his corner and sulks. I also noticed that he looks like his skin has a thin gray film over it. he's not breathing heavy, no missing fins, no other symptoms other than clamped fins and sulking on the bottom. The water has been changed over at least 7 or 8 times since i treated for Ich (this was two months ago) and I've put the carbon back in the filter. The water quality is good, ammonia 0,ph 7,nitrites 0, nitrates 40 (a little high but its the best I can do without adding more chems to the water,it comes out of my tap at that rate).Temp is 78 degrees and NO ONE ELSE in the tank is affected, hes been like this about three weeks now. i just hope whatever it is doesnt spread to his tankmates (small red devil,small monkeyface flowerhorn, med albino oscar (4 inches) and two small convict cichlids.
Thanks in advance,
C

When fish clamp their fins, this can often be a sign that the fish is experiencing irritation. Often this is water conditions but you say your water is okay. However, I suspect your fish may have a parasitic infestation of the skin. Obviously this is just a suggestion as I haven't seen your fish. Does it look slimy at all? If this continues for much longer, try a parasitic medication and see if it helps

thanks for the quick reply. I thought it might be parasitic as well but i would hate to treat the whole tank if just one fish is experiencing the symptoms.
I did a 50% change today and he perked up alot. im gonna try another water change tomorrow and see how he reacts. he's eating readily now, more than ever!

He may just be sulking but the clamped fins doesnt sound good. As said it may be a parasite. also make sure he isnt being bullied, red devils and flowerhorns can be really aggresive

If your tap water has nitrates of 40 think about buying a RO machine. The water comes out nearly pure. You will have to mix it with tap water or add minerals to get the PH and water chemistry stable. I use a RO for my discus tank and i mix it with tap water and it works great