Can Gold Nugget Pleco (L018) and Rachov's Killifish (Annual) Live Together?

Gold Nugget Pleco (L018) is a moderately assertive species (6/10), while Rachov's Killifish (Annual) is generally mild-mannered (3/10). This modest difference means Gold Nugget Pleco (L018) may occasionally assert dominance over Rachov's Killifish (Annual).

Gold Nugget Pleco (L018) and Rachov's Killifish (Annual) 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.

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

There is no temperature overlap between Gold Nugget Pleco (L018) (27–32°C) and Rachov's Killifish (Annual) (20–26°C). This fundamental mismatch makes long-term cohabitation impractical.

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 Gold Nugget Pleco (L018) and Rachov's Killifish (Annual) together, plan for an aquarium of at least 250 litres with a minimum length of 120 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: Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus), Soil / Nutrient Rich, Leaf Litter/Blackwater, Plants - Densely covered. Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Gold Nugget Pleco (L018) requires Smooth Gravel (Sensitive Barbels), 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.

Gold Nugget Pleco (L018) prefers High (River/Stream) flow while Rachov's Killifish (Annual) needs Low (Still Water) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Gold Nugget Pleco (L018) and Rachov's Killifish (Annual) 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.