[DJRansome]

Welcome to Cichlid-forum!

Remove and rehome one or the other. They are too closely related (both Metriaclima) to be in a tank together when you have one of each (mostly).

They are fighting and that is predictable so it may get worse and is not likely to get better.

When you have more than 3 species in a 55G tank you want to shoot for one of each and no look-alikes and all the same gender. Most people choose males because they tend to be more colorful.

Shoot for 8 - 10 individuals in the tank for the all one gender stock plan.

As the fish cause trouble you can rehome. How small are the new ones...mbuna can spawn as small as 2" and count the tail when measuring.

The three white albinos are likely to be an issue too.

The bumblebee (crabro) may become to big/aggressive for the 55G, they work better in a 48" x 18" 75G tank.

 

[DJRansome]

It depends on the cichlid. An Oscar might be one/75G tank. You have African Rift Lake cichlids from Lake Malawi and specifically mbuna.

The first year of their lives they are maturing and there can be more play than aggression.

In an all-male tank 8-10 is the right level of crowding to manage aggression. For mixed gender in a 55G you would think in terms of 15 fish (3 species and 3 males).

Some believe no décor reduces aggression, not sure I believe that but in any case I prefer to manage aggression by stocking fish likely to ignore each other.

Any time you change their environment (their tank) the pecking order can change and aggression is a part of that. Occasional lip locking is not a problem, but if the fish doing the fighting are the same genus or look alike, may as well act now.

 

[DJRansome]

Ignore the non cichlids...I would not expect them to last too many months/years in any case. If you want to keep them I would give them their own tank. the barbs might be OK (barred ones).

Size is not a factor, we stock so the fish can live out their lives in the same tank. Else with Malawi you would be changing tanks every 6 months.

I would not buy Malawi at one inch or if I had to have some exotic fry for some reason, I would grow them to 2" in a separate tank before adding to the adults.

You will have some females and you know you have 3 albinos, so you will be removing and adding...plan on that happening for the first 2 years in an all-male tank.