Can Killifish Live With Discus Fish? 2 Reasons Why They Can’t

Discus fish are one of the most beautiful freshwater fish to have in your aquarium. They are tropical fish and are very colorful. Killifish are also nice fish to keep in the home aquarium too. I have read some questions where people ask if the combination of these two will be nice or wrong. If you are reading this article, it means you want to know if you could keep killifish and Discus fish together, then read to the end.

Can killifish live with Discus Fish? No, it is not recommended to keep killifish and Discus together, because they neither could live in the same water nor do they have the same temperament.

Both killifish and Discus Fish are freshwater fish, although some species of Discus dwell in brackish water.

Being freshwater and tropical fish too doesn’t make them suitable for each other, that’s why they can’t be kept together in the same tank and water.

Why Killifish Cant Be Kept With Discus Fish

1. Differences in Temperament: One of the many problems many aquatic animals have that differentiate them from others is their temperaments.

Discus fish are very fine and gentle fish, in fact, they are so gentle and peaceful that they are said to be shy because they are always hiding whenever there is any other fish in the tank unless there are other Discus fish in the tank.

Killifish on the other hand are very aggressive fish that will bully any other fish that they are bigger and more aggressive than.

So, if you check the temperament of the two fish, you will see that one is very peaceful, and the other is very aggressive and violent, so it is not advisable to keep such a combination together, because the aggressive, which is Killifish will bully the less aggressive which is the Discus in many ways, which includes feeding, fin nipping, etc.

In that case, keeping them together will only result in the stress and eventual death of the Discus fish.

2. Difference in Water Parameters: Apart from their behaviors, another reason and the most important reason why they can’t cohabitate is, that they don’t survive in the same water conditions.

The water parameters of killifish are pH of 6.0 to 7.0, the total hardness between 7° and 10° (120 ppm to 160 ppm), and temperature between 68° and 75° F.

While the water parameters of Discus fish are: pH 6.0-7.0, water hardiness 1-4 ( 18-70 ppm) Temperature 82-86°F, and some species could comfortably live in a temperature of 90°F.

So, if you check the overall water parameters of the two fish, you will see that it is nearly impossible to keep them in the same water without hurting any of them.

For instance, keeping a Discus fish in hard water could kill it, and keeping a Killifish in soft water could also kill it, etc.

In this case, how do you adjust the water to be suitable for both fish, so you see why it is not possible to keep both of them together?, unless one will have to die for the other to live, because, there is no way the same water parameters could favor the two fish.

So, despite being freshwater and tropical fish too, both can’t be kept together in one tank.

To help you more, here are the compatible fish for both of these fish.

What Fish Are Compatible With A Killifish?

Some of the possible suitable tank mates for this fish are:



Large Tetras.


Banjo Catfish.


What Fish Can Discus Be Kept With?

Dwarf Cichlids.

Clown loaches.


Neon Tetras.

Cardinal Tetras.

Rummynose Tetras.


Discus fish and Killifish are never suitable for each other, so, they can’t be kept together due to their huge differences.

I hope this article is helpful to you. Good luck.