Can Black Ocellatus and False Siamese Algae Eater (Stonelapping Minnow) Live Together?

Black Ocellatus is a semi-aggressive species (7/10), while False Siamese Algae Eater (Stonelapping Minnow) is moderately assertive (5/10). This modest difference means Black Ocellatus may occasionally assert dominance over False Siamese Algae Eater (Stonelapping Minnow).

Black Ocellatus and False Siamese Algae Eater (Stonelapping Minnow) 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: Two territorial species may clash over territory, especially in smaller tanks.

Worth noting: False Siamese Algae Eater (Stonelapping Minnow) 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 Black Ocellatus and False Siamese Algae Eater (Stonelapping Minnow) to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations.

The safe temperature window for both species falls between 23°C and 27°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 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 8–15 dGH. Regular testing will ensure conditions stay within this range.

To house Black Ocellatus and False Siamese Algae Eater (Stonelapping Minnow) together, plan for an aquarium of at least 110 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.

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), Shells (Breeding/Hiding), Established Algae (Otocinclus), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Black Ocellatus prefers Low (Still Water) flow while False Siamese Algae Eater (Stonelapping Minnow) needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Black Ocellatus and False Siamese Algae Eater (Stonelapping Minnow) need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.