Can Apistogramma macmasteri and Scat (Brackish) Live Together?

Apistogramma macmasteri is a moderately assertive species (6/10), while Scat (Brackish) is generally mild-mannered (4/10). This modest difference means Apistogramma macmasteri may occasionally assert dominance over Scat (Brackish).

Apistogramma macmasteri and Scat (Brackish) 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. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°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.

Hardness requirements are incompatible: Apistogramma macmasteri needs 1–10 dGH while Scat (Brackish) requires 12–30 dGH.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

To house Apistogramma macmasteri and Scat (Brackish) together, plan for an aquarium of at least 450 litres with a minimum length of 150 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), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Plants - Densely covered, Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Scat (Brackish) is a plant destroyer, which conflicts with Apistogramma macmasteri's requirement for live plants. Compromise where possible or prioritise the more critical need.

Apistogramma macmasteri prefers Low (Still Water) flow while Scat (Brackish) needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Apistogramma macmasteri and Scat (Brackish) 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. Scat (Brackish) is an aggressive eater that may prevent Apistogramma macmasteri from getting enough food.

Because Scat (Brackish) is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Apistogramma macmasteri receives an adequate share.