Can Altolamprologus Compressiceps and Threadfin Rainbowfish Live Together?

Altolamprologus Compressiceps is a moderately assertive species (6/10), while Threadfin Rainbowfish is peaceful (1/10). This notable difference means Altolamprologus Compressiceps may occasionally assert dominance over Threadfin Rainbowfish.

Altolamprologus Compressiceps and Threadfin Rainbowfish both frequent the 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.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

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

Worth noting: Threadfin Rainbowfish is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 24°C and 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Altolamprologus Compressiceps (7.8–9) and Threadfin Rainbowfish (5.5–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–12 dGH. Regular testing will ensure conditions stay within this range.

To house Altolamprologus Compressiceps and Threadfin Rainbowfish together, plan for an aquarium of at least 150 litres with a minimum length of 90 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Shells (Breeding/Hiding), Plants - Densely covered, Plants - Floating. Meeting these requirements will help both species thrive.

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

Altolamprologus Compressiceps and Threadfin Rainbowfish are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Feeding time deserves special attention with this pairing. Altolamprologus Compressiceps is a known shrimp eater and may prey on small invertebrates or nano fish like Threadfin Rainbowfish. Threadfin Rainbowfish is an aggressive eater that may prevent Altolamprologus Compressiceps from getting enough food.

Because Threadfin Rainbowfish is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Altolamprologus Compressiceps receives an adequate share.