Problem with oscars

Question
Dear Nathan,

Really I am prity tensed with the violent behavior of my Oscars. I've a 18 gallon(UK) tank with a power filter and a HOB. I bought 4 Oscars one and half years ago at a age of 3 months probably. Recently after having seen their grouping tendency(my two black Oscars always tends to keep the rest two albino Oscars out of their site, at a corner of the tank) I replaced them in another tank(the albinos). Things were going fine but very recently everything have been changed. Though they were found to clean hard surfaces, slightly chasing each other, a bit fighting... as some pet shop owner told these as there breeding behavior, recently they are fighting violently and the female one hurting the male vigorously. After being badly injured, I separate them by a net partition which resulted in sorrow feeling in between them. All the time they are passing facing eachother of partition. Today they broke that one and again start fighting at a interval. Even they are not allowing any other Oscars in the tank.

What can I do now. I'm facing another problem with feeding them. Here in Bangladesh, pellets for Oscar are not available at all, hence I feed them small fishes usually and meets very occasionally. Though my black two grows about 6"+, growth of the albinos were not that much good and even they are not healthy alike them, the black tigers.

Thats all from me... eagerly waiting for your answer.

Sincerely,
Rakib

Answer
Hi Rakib,

The problem with your Oscars is due to the tank size. You see, Oscars can become very territorial and aggressive in small aquariums. It is usually recommended to keep at least 20 gallons per each individual Oscar. At any rate, the minimum tank size for an Oscar or a pair is 40 gallons. This way, the Oscars will have their own 'territory' and will not exhibit aggressive behavior.

You will have to get a larger tank for your fish, or you must remove one. You cannot keep two in a 18 gallon. They will become stressed, and may die prematurely. You can keep the Oscars together for a few more months, until you get a larger tank - by using a PLASTIC tank divider, one that they can't chew through.

If you have any more questions, feel free to ask again!

Good Luck, and Happy Fishkeeping!