Hi everyone. unhappy home...need some advice on aggressive fish problem

[animal_soulkisser]

I have a 20 gal tank with 1 pleco, 1 rainbow shark, 1 baby african cichlid, and 1 beta. when i purchased the cichlid i was told it would possibly harm my other fish, but being it's young, all maybe okay, so i went with it. I added the cichlid about 12 days ago and it hasn't shown any aggression towards my other fish, instead the cichlid is the one being severely harrassed by my rainbow shark. constantly being chased and 'rammed' by the shark. the cichlid appears very hardy and able to withstand this harrassment quite well but I am very disturbed by it and am wondering if I get another cichlid would it possibly help the situation? I don't want the rainbow shark to be harmed but he's so mean! Is there anything i can try without getting rid of the rainbow shark? he's the only problem in the tank.
also want to mention, once the shark started harrassing the cichlid, my beta started getting very aggressive with the shark and he's definitely afraid of the beta now....

[flynngriff]

I'd strongly recommend taking the african cichlid back to the store you got it from... Even if it's not killing your other fish now, it will eventually. African cichlids are generally much more aggresive than other tropical fish.

[Lexus]

I agree ^

[fish_doc]

Cichlids in general do not do well with other fish. You can get away with the small ones going in a community tank but anything else I would avoid mixing for just the same reasons you have noticed.

[animal_soulkisser]

thanks to those that replied ...
I admit, learning the hard way is NOT a good way to learn...i didn't realize how important it is to educate yourself BEFORE stocking your tank ....now i feel extremely sorry for my fish. Tomorrow i will get another tank just for the cichlid because i love him and don't want to return him. So if i fill a new tank with water from my established tank, the cichlid should be okay...right?
He's my fave

[fish_doc]

Do you have any type of filter on the existing tank? If so moving that over to the new tank would make the most sense. You would leave the gravel and other benefical bacteria in the existing tank and still move some of it over with the filter when you move that. Water does not carry alot of the benefical bacteria necessary to naintain a healthy aquarium. The benefit you will get out of it would be the fish is already conditioned to the pH and other levels in the current water which would eliminate some of the stress of moving the fish.

[animal_soulkisser]

Yes....absolutely makes the most sense to transfer the filter to the new tank...you are sooo smart, thank you.....!!!!

[ron v]

How big is your new tank? If you move the filter, remember that most of the "good" bacteria is in that filter. More than would be left in the gravel and decor. So when you split up your fish, most of the bio-load needs to be with the established filter. Maybe leave the cichlid with gravel, etc. and move everybody else to the new tank and old filter... Just a thought.