I know their is an article on this but I cant seem to find the answer for my question there.
I have had an Albino Oscar and a Tiger Oscar for about a month now. Bought them together and have had them in the same tank. Up until about yesterday they were doing fine. Yesterday I noticed that the water was getting a little cloudy. Not sure if it has anything to do with the fact that I added some Topfin conditioning salt about 3 days ago because I was told that it helps with the nitrate. Not really to worried about the cloudy water because I know that happens I added the 24 feeder minnows I have been giving them every Sunday for the past few weeks.
Now the two of them are gasping all of a sudden. They havent eaten any of the feeders that I cant tell. And they havent eaten any of their normal pellet food. which is truly odd because they normally eat alot. Not really sure if I should try changing out the water?
Please help, Nate

This could certainly be a serious matter which needs attention ASAP. Fish shouldn't gasp like this. The fact that both fish are doing it points to water conditions. The first three things you should do straightaway is check ammonia, nitrite and then address the oxygen. The ammonia and nitrite should be zero and no higher. However, if they are above zero, it won't necessarily mean the fish will gasp, they will probably only do it if it is very high. Fish can also breathe heavily if there is not enough oxygen in the water. Have a look at where the water comes back into the tank, make sure there is plenty of disturbance on the surface of the water with bubbles being created. Please check these three things first. If they are okay, we'll have to look little further afield to see what could be wrong.

I would also suggest taking whats left of any feeders out of the tank immediately.

Working on getting the feeders out now. Am going to have to run to the pet store and get a test kit. The tank is pretty new and I havent purchased one yet.

Where are the fish gasping, if its at the surface or at the filter outlet then it is lack of oxygen, adjusting the filter outlet to ripple the water or getting an air pump should cure this. If they are gasping generally anywhere in the tank then it is serious and needs immediate attention, water quality would be the obvious problem, so post the test results

Try some filter aid to remove the cloudyness of the water, the cloudyness may be cause by excess bacteria and filter aid clumps them together to make them bigger which means they then get trapped by the filter

Feeding feeder fish can introduce illness to the tank, its not necessary, but if you will feed feeders to your oscars breed your own so you know they will be disease free

Well the results from the initial test's on the Nitrate and Nitrite were high. So I have since did a 75% water change and gravel vac. I added a air pump and bubble bar and modified my filter so it has more of an "ripple" effect at the surface. I just preformed another test on the water and the levels are where they should be, Nitrite is at 0 and Nitrate is less than 20. I also will not be feeding them feeders anymore and will be feeding them krill now on occasion. Thanx for the help guys. So far everything seems to be back to normal. Any other advice you could give would be great.

Thanx again, Nate

Did you check your ammonia as well?

It would be a good idea to try and work out why this happened. Keep an eye on those nitrite levels, they could start creeping up again. Take a look at your cleaning regime, have you clean your filters lately? If so, how did you clean them?