Cichlids Fighting, Help!

[JMeyer]

Hey all,
So I have had the same four cichlids for about a year now. There was of course some aggression at first but everything has been peaceful for a while now. Except, all of a sudden, my largest cichlid has starting going after my smallest one. I will say the largest one was always the most aggressive, but just here recently he has been targeting the small cichlid. It kind of just happened out of nowhere so I'm not really sure why they are suddenly fighting. Any help would be great. The tank is 29 gallons if that helps.
Here are some pictures for reference:

 

[mambee]

You have various Lake Malawi mbuna and maybe a hap. Mbuna are naturally aggressive and are usually intentionally overcrowded to spread out the aggression. I'm afraid that a 29 gallon tank is too small for them. You probably purchased them as juveniles and they have gotten more aggressive as they have matured.

 

[TMRC Exotics]

29 is too small for any mbuna. A 55 gallon is needed to give them adequate space. With only a 4 a 40 breeder may be large enough.

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[54seaweed]

40b would have a bigger foot print over a 55g allowing more swimming room

 

[TMRC Exotics]

40b would have a bigger foot print over a 55g allowing more swimming room

Yes and no, there is more floor space but with the way mbuna claim territory a 4 foot length is preferable to a 3 foot length.

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