I have a oscar that is 3 inches long. and i just got a red belled pacus that is two inches long. the pet store said they are good tankmates but the oscar is nipping at the pacus. Will they get along alright or will the oscar kill and try to eat the pacus?. the little oscar will eat a good sized goldfish but it will only eat the head off and spit the rest out. should i leave them together or seperate them. I dont want to lose the pacus. I have them in a ten gallon tank right now but soon i plan on getting a bigger tank. I thank you for all your advice.