Can Badis (Chameleon Fish) and Rachov's Killifish (Annual) Live Together?

Badis (Chameleon Fish) is a moderately assertive species (5/10), while Rachov's Killifish (Annual) is generally mild-mannered (3/10). This modest difference means Badis (Chameleon Fish) may occasionally assert dominance over Rachov's Killifish (Annual).

Badis (Chameleon Fish) and Rachov's Killifish (Annual) both frequent the Bottom (Substrate) and Middle (Open Water) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Shrimp eaters may also prey on very small nano fish.

Worth noting: Rachov's Killifish (Annual) is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Badis (Chameleon Fish) and Rachov's Killifish (Annual) to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

The safe temperature window for both species falls between 20°C and 25°C. Aim for the midpoint of this range (around 22.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 4–12 dGH. Regular testing will ensure conditions stay within this range.

To house Badis (Chameleon Fish) and Rachov's Killifish (Annual) together, plan for an aquarium of at least 60 litres with a minimum length of 60 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Sand (Sifters), Plants - Densely covered, Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Soil / Nutrient Rich. Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Badis (Chameleon Fish) requires Sand (Sifters), while Rachov's Killifish (Annual) requires Soil / Nutrient Rich. These substrate types may be difficult to provide simultaneously. Compromise where possible or prioritise the more critical need.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Feeding time deserves special attention with this pairing. Badis (Chameleon Fish) is a known shrimp eater and may prey on small invertebrates or nano fish like Rachov's Killifish (Annual).