It’s been two months since I got my new fish. How are they doing and how are they getting along with their tank mates?
Pretty well so far, I think, although it may still be early days. The severums are growing, probably at least to double size, and starting to lose the juvenile, stripy markings.
The tank mates have been doing well too, at least most of the time. I lost a few fish during the first month. Maybe because of stress and new tank mates, maybe because of extra water changes; maybe changes to diet – who knows. Then, for the last weeks, the day temperature in the room has been over 32C and that has been too much for several platies and a cupido.
The tank is doing fine, looking better than it has for a long time. Probably because I am back to regular, weekly 25% water changes. It turns out that both green and black algae do go away if the water is changed regularly, just like all the books say (or the algae eater did its thing?)

Concerns about Stocking Compatibility
One thing I am watching out for is how well the severums will mix with the other fish already in the tank. As previously described, my aquarium has been a community tank so far and adding a handful of large, somewhat temperamental fish could well change it into something else.
Among my initial concerns:
- Will the severums and the corydoras get along
- Will the rummy-nose tetras get eaten?
- How will the different cichlid species react to each other?
- Wil the severums accept the gouramis
Here is how things are going so far. In my tank. These are living creatures and just because a thing – good or bad – happened in my tank, doesn’t mean it will happen anywhere else, , all things being equal). I lost some fish, platies and cupidos, but none of them were doing well before the severums were added, so that doesn’t have to mean anything.
Severums and Severums
This is the conspecific aggression. I see that already, with the oldest looking fish generally being the boss, and one of the smaller ones looking increasingly ragged. They chase each other sometimes,but behave during meals.
Severums and Corydoras
The cories are small bottom feeders who may come into the severums’ area of interest. So far there are no problems. Perhaps because the cories are most active at night, perhaps because they are already cautious because of the cupidos and the algae eater.
Severums and Rummy-nose tetra
The severums are still too small for the rummy-noses to fit into their mouths. However, I notice that the rummy-noses are less active lately, spending most of the time in one corner of the tank, together with other fish too. That may also be due to the tank getting hit by direct sunlight at the moment and the fish hiding from that.
Platies and Severums
Severums doesn’t seem to care about them. The platies aren’t doing too well though and I have lost 3 or 4 since the severums moved in, but that is probably due to other factors, like the water temperature. I have not had a lot of success with platies in this tank.
Knife Fish and Severums
So far they ignore each other. The knife is a large fish but also hides most of the day (except when feeding) so there isn’t much to fight about. All peaceful so far.
Cupidos and Severums
Some aggression observed and I speculate if the weaker-looking cupidos are getting worse. Maybe they are and maybe this has been going on over long time, only i just see it now. Maybe it is changes to the food and maybe the weekly changes of water that isn’t ideal to the fish either.

On Apr 19 one of the Cupids died and another went yesterday, but no obvious explanation why, except that it was the worst looking one(s). So my assumption is that some of them may not make it for one reason or another.
Silver-tipped Tetra and Severums
My silver-tipped tetra has been the only one of its kind for a while. It is still too big to be lunch and has been ignored so far. It is not hanging in the same corner of the tank as the rummy-noses.

Coming Up
Cooler weather should be on its way, which will hopefully reduce stress on all fish. The remaining platy may last longer together with the cupidos. Time will tell.