Oscar Illness - Cloudy Eyes

Question
Not only does 1 of our Oscars have both eyes clouded over (if he was human, I'd swear he had cataracts# but over the past couple of weeks he's been very lifeless, staying in the corners by the filter tubes and not interested in eating. I'm praying that it's not from the nasty goldfish feeders we've been feeding them. Now ... one more of our Oscars is displaying signs of melancholy as well. Her eyes still look ok, but she's once again not interested in eating #I'm not positive of the sex of both fish, that's just what we are guessing at this point#. We have 4 Oscars in our 75 gallon tank, along with a plecostomous & small cat. We perform water changes about 1x per week because they're such dirty fish #and they're my babies!). When we have the water tested it comes out ok. Do you have any suggestions? We are also concerned that there may be "hole in the head".

Answer
hello,

This sounds like a common disease among fish. I would suggest adding aquarium salt to your tank. It well tell you on the back of the package for how much salt you should put into your tank. Also make sure you only feed your fish once a day to keep eating diseases away from your fish.