Severum bullying

[duanes]

I believe cichlids (including oscars and severums) need at least a minimum of 10 gallons per inch of adult fish to keep aggression down. Aggression is all about too big a fish in, in essence, what is a puddle.
So as and example 3 ten inch severums, need at least 100 gallons.
Oscars will reach 14-15" as adults. A pair need minimum 150 gal tank.
Anything less and you are bound to have unchecked aggression.

 

[Skalper666]

Your issue with aggression is cause by the small space they are confined in. A 75g is barely doable for a single oscar only. You'd have a tough time keeping one alive in that. A 20g for all of those fish is crazy even at their current size. Unless you do extreme water changes they will not live long.

 

[smjack]

Yes, if you bought a pair, its asking for trouble, esp if m/f. Return 1 of the oscar or rehome. Also had trouble with severum ( I had 4). I bought driftwood with lots of branches. Peace at last.

 

[BadBrad]

You may want to upgrade to a bigger aquarium. You have two Oscars so you may think of something around the size of 90 gallons plus.

 

[Audaxcity]

65g is too small for an Oscar considering they can get absolutely HUGE. I'd say you're pushing your luck with just a single pair of Severums.

Might I interest you in another species? A group of 4 Festivums OR 5-6 Keyhole Cichlids OR 5-6 Angelfish would work in 65g and they kind of have that Severum look and behaviour.