Hi and welcome to the forum
What are the tank dimensions (length x width x height)?
What is the GH (general hardness), KH (carbonate hardness) and pH of your water supply. This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).
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Any chance of a picture of the fish and tank?
If the pictures are too big for the website, set the camera's resolution to its lowest setting and take some more. The lower resolution will make the images smaller and they should fit on this website. Check the pictures on your pc and find a couple that are clear and show the problem, and post them here. Make sure you turn the camera's resolution back up after you have taken the pics otherwise all your pictures will be small.
If you can't do pictures, can you post the scientific name of the cichlids in the tank?
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By adding new fish to the tank, you have introduced a bunch of intruders into the severum's home. Now the severum is upset at having intruders in their home and they are trying to chase them out of their territory.
You can try rearranging the decorations in the tank to break up territories or just wait a week and hope things settle down.
You could have compatibility issues if you are keeping African Rift Lake cichlids and soft water cichlids together.
