Oscar - Breeding Behavior?

Question
My Oscar, Jaws, is approximately 3 years old.  Started one weeks ago, moving rocks around, very skittish, huddling in the corner of the tank in an area he/she has made devoid of rocks.  ? is how long will this behavior go on, he/she is exhausted due to the nervous breakdown he/she is having.  Anything I can do to make he/she more comfortable, turn off tank lights, cover tank, remove Jaws 3 small goldfish friends, etc.????? I've treated water w/shock guard, removed any sharp shells/rocks, fed only fav foods (dried shrimp), stayed away from tank to give Jaws some quiet time, etc. Seems like last time we only "nested" for a few days.

Answer
Hi Lisa,
It is normal for Oscars to move things around in a tank.  I have some, and they change the decor daily.   Oscars must have big tanks.  One Oscar needs 60 gallons of water just to himself, Two Oscars you must double that, and so on.  The ideal water temperature for Oscars is 77 degrees.  Water changes of 25% should be made every week, sometimes more depending on your Ammonia level.  The ammonia level should be zero, the nitrates zero, and nitrates very low.  You can buy these test kits at your pet store, and they are handy to have.  Ammonia is the number one killer of fish, so make sure your water chemistry is right.   He should have a varied diet to keep him healthy, and happy.  Oscars do best in neutral water which means a PH of about 7.0.  Goldfish need cooler waters, and alkaline waters.  They really shouldn't be with Oscars.  Shells make the water alkaline, which is not very good for Oscars.  
His diet must consist of insects, crickets are very good for him, and most Pet Stores sell them.  Sometimes you can find ants, and other insects.  Never feed him crickets or insects that you find on the ground, they may have pesticides in them, and that would kill your Oscar.  He should also have worms that you can buy at the bait store.  Clean the worms first by leaving them in oats for about a week.  They too must be bought.  You may also find minnows at your bait store, which is also very good for him.  Frozen fish that come from rivers, and lakes are also a very good source of food for your Oscar.  Unfreeze the fish before giving this to him.  (Fish from salt water lakes, you must avoid)  Feed him green beans, broccoli, peas, spinach, and carrots.  Now and then give him fruit, such as mangoes, or bananas, and apples.   Avoid citrus fruit.   Oscar pellets, and sticks, a good quality flake, bloodworms, and other frozen food that you find at the pet store is excellent for him.  You must vary his diet.  I would recommend the frozen veggies that you find at your market.  Blanch the veggies first before giving them to your Oscar.  Never feed him feeder fish.  They have no nutritional value, and are very often full of disease.  Oscars who do not have the right diet, and aquarium space do get sick.  They need all the vitamins they can get to stay strong, otherwise, they will get very weak, and sick.
I would remove the goldfish, and leave her/him alone in the tank.  
He may also be constipated.  Feed him cooked frozen peas with the first layer removed, and nothing else for a day or two.  This should help him.  Peas clean out their system, and they should have peas one day a week.  On the day you feed peas, feed nothing else.  Do not worry about him moving things around in the tank.  It surprises me that he has not done this until now!!  Make sure he cannot hurt himself on anything in the tank.
I hope this helps, and if you have any other question, please to not hesitate to write me.  I love Oscars, and they make great pets.
Lynda