[b[i]]Recently, we introduced some new fish to our 150 gallon tank. The Oscar and a few other fish have been living in this tank for at least a year. One of the fish that we introduced has a small "rubbed" spot on its side that we didnt see until we put it in the tank. We contacted the store that we got it from and they gave us a treatment (cant remember the name, for a possible bacterial infection), for this. They were aware the we had other fish and we were told that the it wouldnt hurt the others but in fact would help them if there was a bacterial infection in the water. Anyway, this was about a week ago, and since then, my Oscar has been changing colors. It will go from be very pale, as it was before the treatment, to now very dark in color. It has never gotten back to its pale color. It changes from one shade of darker to dark. It seems to have lost its appetite and will tilt to one side sometimes. I need some advice as my husband will be very upset if something should happen to Oscar. [/i] [/b]

Because you have treated the tank with a medication you may have killed the beneficial bacteria in your tank. You need to test your water for the ammonia, nitrite, and nitrate levels. It is possible that you have poor water quility.

Oscars get pale when they are stressed... i suggest you test your water as bowhunter suggested.

-Art

As art said, Oscars go pale when stressed, so your oscar was probably stressed before, they tend to have a darker colour so i wouldnt worry yet, but if you can, post your water readings ( ammonia, nitrite, nitrate and Ph).
also, what temp do you hav in your tank and is the temp constant or does it change alot.
this can stress the fish big time.

bowhunter wrote:


agree on this with bowhunter. kindly re-test your water.
usually, any injuries of fish would heal in no time if
you have pristine water in your tank without medication.