Can Apistogramma viejita and Black Ruby Barb Live Together?

Apistogramma viejita is a moderately assertive species (5/10), while Black Ruby Barb is generally mild-mannered (3/10). This modest difference means Apistogramma viejita may occasionally assert dominance over Black Ruby Barb.

Apistogramma viejita and Black Ruby Barb both frequent the Bottom (Substrate) 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. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

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 Apistogramma viejita and Black Ruby Barb 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 24°C and 26°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 5.5 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 2–8 dGH. Regular testing will ensure conditions stay within this range.

To house Apistogramma viejita and Black Ruby Barb together, plan for an aquarium of at least 80 litres with a minimum length of 80 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), Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Plants - Densely covered. Meeting these requirements will help both species thrive.

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. Black Ruby Barb is an aggressive eater that may prevent Apistogramma viejita from getting enough food.

Because Black Ruby Barb is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Apistogramma viejita receives an adequate share.