what kind of fish can i put with oscars

Question
I have a 55 gallon tank with two 30 gallon filters.  I keep my water between 77 and 82 degrees.  I can't get the ammonia level down from .5-1.0.  I have tried pellets,
stress zyme to get the level down.  Water change, 25% twice a week.  but after every test, it reads .5-1.0 ammonnia.  I have in the tank a jack dempsey, a black convict and a oscar, with 3 goldfish... even before i put any fish in the tank, by ammonnia level was the same.  I washed everything off before i put in tank, including rocks someone gave me from there tank, they had lying around.  (gravel)..   Also, can the fish cohabitate with one another?  I want to put a buttakaferi in the tank with them, will there be a problem (talapia)

Answer
Hi Raymond,
You have to let a tank cycle before adding any fish to it.  The ammonia level must be zero, and nitrites must be safe before you add any fish.  Right now your tank is overstocked, which could be another reason for ammonia.  Ammonia is the number one killer of fish.
An Oscar needs a 55 gallon tank all to himself.  Two Oscars you must double that, three Oscar triple that, and so on.  If not given this space to grow, his internal organs will not have enough room to develop properly, he will get sick, and their is no medication for this, so the fish dies.  This is very sad.  Too many vendors don't tell you the truth on stocking tanks.  They do not care, all they are interested in is the almighty dollar.  The Oscar when kept in good conditions, is a wonderful little pet.  Right now, the Jack Dempsey, convict, and three goldfish are too many in this tank.  He should be alone.
The Oscar is not a bad fish, but will defend himself if he has too.  He is no match for the Dempsey who is true to his name, and sooner or later will attack your oscar with intent to kill, and will succeed.  Jack Dempseys also need big tanks, and should be kept alone.  They are killers, fighters...will eventually have their way, and the whole tank to themselves.  The goldfish live in cool waters, and should not be kept in 77 degree water.  We cannot change the way fish live.  This is impossible to change.  These fish do not belong together.  Forcing fish to live in conditions which are not good for them cause them stress, and sickness.  They also do not eat the same foods.  Goldfish are vegetarian, Oscars are carnivores.  Never feed your fish feeder fish, as they have no nutritional value, and are sometimes full of disease.  Oscars need insects such as crickets, bought at pet stores, worms, bought at bait stores, and then cleaned in oats.  They also must be fed fish like minnows, which you can also find in bait stores.  Make sure you buy the regular fish, and not the scented ones.  You can also buy him frozen fish at the market, which come from lakes, and rivers, no salt water fish.  Keeping an Oscar is wonderful, but keeping him in bad conditions is pitiful for the Oscar.  When we make a commitment to keep fish, we must think this over very very well.  Gets lots of information, as we just cannot force fish to live together who are not meant to live together.  We cannot change nature.  You decide which fish you want to keep.  If you want lots of fish in your tank, you will have to go with smaller fish.  If you want to keep the Oscar, all your fish must go back to the pet store, and ask for a credit.  If you decide to keep the jack dempsey, then he must be kept alone.  Is you want goldfish, then keep the goldfish, but remember goldfish have needs too, and each goldfish needs 10 gallons of water, which means no more than 5 goldfish in your tank.
This is a common mistake that many people make when adding fish.  The vendor who sells you these fish, should have known better if he knew what was into your tank.
To bring the ammonia level down, you must make small water changes everyday of 10%, get rid of some of your fish so that the tank will hold what it is suppose to hold.  Ammonia is the number one killer of fish, so you must deal with the ammonia issue before they all get sick.
I know this is bad news, but it is better to know the truth now, than later, and having all your fish sick, and die.
I hope you understand, and if you have any questions please do not hesitate to write me.
Lynda
Hi!
I thought I did give you more information, but I guess I was typing too fast.  The Jack Dempsey is a beautiful fish which grows to 10 inches.  He also needs a 55 gallon tank to himself.  He is very aggressive.  He eats mostly anything, quality flakes, pellets/sticks, frozen foods...he also needs a varied diet.  He likes minnows. much like the Oscar.  The convicts, are aggressive fish, you can keep a couple in a 30 gallon tank.  They too wiil eat flakes, worms, insects, pellets, frozen foods.  They are not hard to keep, but like the name says "Convicts"  this is an aggressive fish.  Goldfish are usually not aggessive.  They are vegetarian, need veggies, peas, frozen veggies, such as green beans, carrots, spinach, broccoli, and sometimes you should feed them bloodworms.  Pellets made especially for them may be found at your pet store.  One goldfish needs 10 gallons of water, so three needs 30 gallons...they do get quite big, and even in a 30 gallon tank, I would think that at some point, they would need a bigger tank.  You must always think of fish of the size they will reach when mature.  Even if a fish is small now, if the fish reaches 10 inches when mature, he must be put in a 55 gallon tank now, and not later...if you have two little fish that will grow to 10 inches, you will need a 110 gallon tank.  I think I explained to you the reason why.  If you don't, their internal organs will not have any place to grow, so the fishes growth will be stunted, he will get sick, and die.  If his kidneys have no place to grow, or his liver, or heart, this would be awful, and their death is a sad one.  I hope you understand.  I know it is lots to understand at the moment, but please just ask me another question if you are unsure.  Be precise, and I will do my best to answer you.
Thank you for your nice rating, I appreciate this very much.
Have a nice day
Lynda