Hostile fish

I’ve had my tank for about 6 months now and in the past week or so the fish have just been fighting, there is a pair of cichlids in there that are showing breeding behaviour so should I take them out or just wait it out, unfortunately one of my fish died from stress and I don’t want this to happen again so please reply and I’ll give any information asked for

What sort of fish are fighting?
How big is the tank?
What sort of fish died?
Pictures and video of the fish?

Firemouth cichlid and gold gourami, firemouth cichlid fighting the other firemouth chichlid, 40 gallons, dwarf gourami was the fish that died, I don’t have a video of the fish fighting now but if I do I’ll post it on here thanks

Cichlids aren't community fish and they don't do well with other fish that aren't cichlids such as the dwarf gourami.

I’ve set up a new tank so I’ll move the cichlids into it soon

I had 8 African Cichlids and they took over my 55 gallon tank and I had to remove all the other fish except a pleco.

When you say fighting, do they grab each other by the mouth and push each other back and forth, or do they try to rip each other apart and bite their sides and fins?

If they are mouth locking and pushing each other, that is them testing each other for breeding.
If they are trying to take pieces out of each other, then they are fighting over territory and need separating.

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Dwarf gouramis are genetically weak fish and a lot of them carry TB and or the Iridovirus, neither of which can be treated. If you had a male gourami that died, it was probably bullied by the other dwarf gourami and the gold gourami, both of which are males. All gouramis are highly territorial and you should only keep one species per tank.

The firemouth cichlids should be fine with some gouramis in a tank that is 3 foot long or bigger.

to the Forum!!

Cichlids can be very territorial, and it can be difficult to find a good balance in species, numbers and personalities.. Years ago I had some younger Firemouths and Geophagus, in a 75 gal community tank with some Larger Tetras and Gourami. This was when I didn't know much about Cichlids other than that they were pretty and displayed interesting behavior. It didn't take me long to learn that larger Cichlids don't mix well with others... I ended up setting up a 30 gal community tank and moved all of my Tetras and Gouramis into the new tank. The larger tank became a south American Cichlid tank with a single Pleco.