What fish can live with Upside-down Catfish?

Usually safer companions on this hub include Boesemani Rainbowfish, Congo Tetra, Dwarf Gourami. Open each pair check before you buy — the list is a shortlist, not a guarantee.

What tank mates should you avoid with Upside-down Catfish?

Avoid Jack Dempsey, Oscar based on size, temperament, or predation risk on this profile.

What size tank do Upside-down Catfish need for a community?

100L is the planning floor for adult swimming space and bioload. A 122L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.

Upside-down Catfish tank mates

Upside-down catfish communities are two tanks stacked: the catfish own the underside of floating cover after dark, so usually-safer neighbours leave that film alone. Congo tetras and boesemani rainbows work the midwater; a dwarf gourami is workable when it has its own surface corner. Corydoras and bettas sit in caution — same tank, different stress maths once numbers, feeding, or the night-shift surface lane collide. Jack dempseys and oscars sit in avoid on size. Feed the ceiling at lights-out so you can count the group.

Our first pick

Congo Tetra. Midwater school that ignores the upside-down night shift under floating cover. Keep a real tetra group so they hold the middle instead of picking at the surface film. Run the pair check →

Common mistakeBuying a single upside-down catfish as a curiosity is how keepers invent a “shy” species. One fish hides in a cave all day and never shows the posture that made you buy it. Plan for three or more in roughly 100 litres with floating plants or overhangs so they have an underside to work. Under-stocking and bare bright glass erase the behaviour people then blame on the fish.

Evidence: partially verified

Confidence: high

Each name below opens a pair check with Upside-down Catfish. That check is the decision, not the list itself.

← Full Upside-down Catfish profile·Compatibility checker·Tank builder·More catfish

Usually safer companions

Conservative shortlist from this profile. Open a pair page before you buy.

Boesemani Rainbowfish Pair check
The Upside-down Catfish profile lists Boesemani Rainbowfish as both safe and a recommended pairing. Boesemani Rainbowfish schools in groups of 6 or more, so plan room for the whole group rather than one fish.
Congo Tetra Pair check
The Upside-down Catfish profile lists Congo Tetra as both safe and a recommended pairing. Congo Tetra schools in groups of 8 or more, so plan room for the whole group rather than one fish.
Dwarf Gourami Pair check
The Upside-down Catfish profile lists Dwarf Gourami as both safe and a recommended pairing. Dwarf Gourami is a peaceful beginner-care species with a 60L minimum. Run the pair checker for your specific tank before stocking.

Risky or situational

May work with more water, a mature system, or a species-only setup. Read the pair page before you experiment.

Betta Open pair check
Betta is rated semi-aggressive, so expect chasing, fin damage, or display behaviour directed at Upside-down Catfish. Run the pair checker before stocking.
Corydoras Catfish Open pair check
Marked risky or situational on the profile. Tank length and group size change the outcome more than a temperament label does.

Fish to avoid with Upside-down Catfish

Predation, aggression, or space rules on this profile. Treat these as poor default mixes.

Jack Dempsey See why (pair)
Jack Dempsey reaches 25cm and is flagged predatory. Upside-down Catfish at 10cm is prey-sized for it. Jack Dempsey is rated aggressive and Upside-down Catfish is rated peaceful. No community-style planning carries that gap.
Oscar See why (pair)
Oscar reaches 35cm and is flagged predatory. Upside-down Catfish at 10cm is prey-sized for it. Oscar needs at least 300L, far above the 100L minimum for Upside-down Catfish. The tank that houses one stresses the other. Oscar is rated aggressive and Upside-down Catfish is rated peaceful. No community-style planning carries that gap.

Tank size and groups

Published minimum for Upside-down Catfish: 100L. Group minimum 4 (schooling).
Compatibility changes when the tank is too short for turning, too little for a real school, or too warm for one species and not the other. That is why pair checks include tank context, not only temperament.
Nearest litre hub to this minimum: 100L hub.

Plan before you buy

Start a pair check with Upside-down Catfish, or open a starter plan with the top safer companions in the builder.

Open pair checker Open this plan in builder

Tank hubs: 100L

Filtration & heating

A 100L minimum tank for Upside-down Catfish needs a filter rated for at least 400L/hr turnover and a heater maintaining 24–28°C.

Filter size guide →Heater size guide →Tank setup checklist →Beginner plants guide →

Related (care + temperament)