Best Kuhli Loach Tank Mates

What makes a good tank mate for a kuhli loach?

A good kuhli loach tank mate is a peaceful fish too small to eat a kuhli, that is happy in soft, slightly acidic water, and that leaves a shy bottom dweller alone. The kuhli loach is a slender, eel-like loach from Southeast Asia. Seriously Fish says the fish sold as kuhli loaches are almost always Pangio kuhlii / Pangio semicincta in its Pangio semicincta form, and that true P. kuhlii is endemic to Java and may never have reached the hobby. Our ranges follow the Seriously Fish data for the traded fish.

Four criteria decide the ranking below.

1. Shared soft water. The kuhli loach needs 74–79 °F (23–26 °C), pH 3.5–7.0 and 0–8 dGH. Its pH ceiling is the strictest limit: species that need hard, alkaline water share no pH range with it.
2. Too small to be a predator. A kuhli grows to 3.9 in (9.9 cm). Large predators such as oscars, which Seriously Fish and Aquarium Co-Op say eat any fish small enough to swallow, rule themselves out.
3. Calm around a shy fish. Seriously Fish and Aquarium Co-Op both describe the kuhli as peaceful, shy and nocturnal. Seriously Fish adds that groups often pack into a single refuge to rest, so hiding places matter more than open space.
4. Nothing the kuhli will eat. Kuhli loaches do not harm adult fish, but Seriously Fish says they may take eggs and fry, and Shrimp and Snail Breeder says they can eat newly hatched shrimp.

Swim level helps kuhlis more than most fish. They live on the bottom, so mid-water schoolers such as rasboras and tetras barely meet them. This page is part of our tank mates by species series, which ranks each species with the same method.

Which fish are the best kuhli loach tank mates?

The best kuhli loach tank mates are small, peaceful mid-water schoolers from soft water, plus a few calm bottom dwellers. The species at the top of the table above are described below with the evidence behind their scores.

Harlequin rasbora

The harlequin rasbora scores 10/10, the highest kuhli result in our data. It shares 74–79 °F (23–26 °C) and pH 5.0–7.0, swims in mid-water, and Seriously Fish calls it very peaceful and lists loaches among its suitable companions. It needs a school of 8.

Cardinal, GloFish and neon tetras

Cardinal tetras score 9/10 and GloFish tetras 9/10. Practical Fishkeeping says cardinals do not bother other species, and Seriously Fish lists small catfish among their suitable tank mates. The GloFish tetra’s base species, the black tetra, has a fin-nipping reputation according to Seriously Fish, but a kuhli has no trailing fins to nip. Neon tetras score 8/10; their shared temperature is narrower, at 74–77 °F (23–25 °C).

Corydoras and bristlenose pleco

Corydoras score 9/10 and bristlenose plecos 9/10. Both share the bottom with kuhlis, which our method marks down slightly, but neither is a threat. PlanetCatfish calls the bronze cory a perfect community citizen, and the corydoras tank mates guide ranks its other companions. The bristlenose needs one caution: Aquarium Co-Op says males can guard caves against other bottom dwellers, so give a kuhli group refuges the pleco does not claim.

Betta and dwarf gourami

Bettas and dwarf gouramis both score 7/10. They stay in the upper and middle water, while the kuhli stays below. Both are semi-aggressive, so the shared tank rises to 29 US gal (110 L). The kuhli loach ranks highly on the list of fish that live with bettas, because it is shy and rarely crosses the betta’s path.

Guppies

Guppies score 8/10, but the water is a compromise. Guppies prefer harder, more alkaline water, and the two pH ranges meet only at their edges (pH 7.0–7.0). Seriously Fish and Aquarium Co-Op describe guppies as very peaceful, so behaviour is not the issue.

Which fish should never live with kuhli loaches?

Kuhli loaches should never live with fish that can eat them or with fish that need different water. Several species fail outright in our data, for three different reasons.

Predators

Oscars score 3/10. An oscar reaches 14 in (35.6 cm), and Seriously Fish and Aquarium Co-Op describe it as a predator of any fish small enough to swallow, which includes a 3.9 in (9.9 cm) loach. The pair would also need 125 US gal (473 L).

Different temperatures

Goldfish score 3/10 because they share no temperature range: goldfish need 59–70 °F (15–21 °C), and fishkeeping.co.uk adds that goldfish eat anything that fits in their mouth. Zebra danios score 3/10 with only 74–75 °F (23–24 °C) shared. Discus score 3/10 from the other end of the scale: discus need 79–86 °F (26–30 °C), and the kuhli’s range meets that only at its upper limit.

Hard-water species

Mollies (3/10), nerite snails (3/10) and mystery snails (3/10) share no pH range with kuhli loaches. Mollies need pH 7.5–8.5, and Seriously Fish and Aquarium Co-Op say they become disease-prone in soft or acidic water, the very water a kuhli prefers. The snail verdicts are explained in the next section.

Can kuhli loaches live with shrimp and snails?

Kuhli loaches can live with adult shrimp, but baby shrimp are at risk, and snails are limited by water rather than behaviour.

Shrimp

Aquarium Co-Op says kuhlis are not known for eating shrimp, while Shrimp and Snail Breeder notes that they can eat small or newly hatched shrimp and that large adults may take adult dwarf shrimp. Our data therefore scores cherry shrimp at 7/10 and amano shrimp at 7/10, both with a caution verdict. A cherry shrimp colony that is meant to breed needs dense cover; the guide to cherry shrimp tank mates covers that in detail. Amano shrimp, at 2 in (5.1 cm), are larger, and Aquarium Co-Op states they cannot reproduce in fresh water, so the baby-shrimp risk does not arise for them.

Snails

Snails fail in our data on pH alone. The nerite snail needs pH 7.2–8.0 and the mystery snail pH 7.2–8.0, both above the kuhli loach’s ceiling. Behaviour is not the problem: our kuhli data records that it does not eat snails, and Aquarium Co-Op even lists kuhli loaches among the fish that mystery snails can live with. The conflict is about chemistry. Soft, acidic water suits the loach, while snail sources ask for harder water. Read about GH and KH in aquarium water before mixing them. The aquarium snail tank mates page lists fish that share snail water.

Are kuhli loaches snail-eating loaches?

No. Kuhli loaches are often assumed to eat snails because some loaches do; Aquarium Co-Op and Applesnail.net name certain loaches as snail predators in our mystery snail data. The kuhli is a different case. Seriously Fish describes it as a micropredator that sifts the substrate for insect larvae and small crustaceans, and Aquarium Co-Op says kuhlis are not known for eating snails. Our kuhli data records its diet as carnivore, taken from sinking pellets, gel foods and bloodworms in the aquarium.

The practical point is that a kuhli group will not control a snail outbreak. It also means a snail tank and a kuhli tank fail together for water reasons, not because the loaches attack. If you want snails, choose species from the snail guide; if you want kuhlis, plan around soft water.

What size tank do kuhli loaches and their tank mates need?

Most kuhli loach pairings in our data need 20 US gal (76 L), and pairings with a betta or dwarf gourami need 29 US gal (110 L). The shared figure takes the larger of the two species’ minimum tanks, adds a margin when one species is semi-aggressive, and rounds up to the next common tank size.

10-gallon tank

A 10-gallon tank is below the kuhli loach’s own minimum of 15 US gal (57 L). That figure comes from Seriously Fish’s 60 × 30 cm base, while Aquarium Co-Op recommends 20 gallons or more for a group. Our guide to fish for a 10-gallon community tank we recommend lists species that do fit that size.

20-gallon tank

At 20 US gal (76 L), a kuhli group can share the tank with harlequin rasboras, cardinal, neon or GloFish tetras, corydoras, a bristlenose pleco, guppies or shrimp. Not all of them at once: a school of 8 cardinals and 6 corydoras alongside 5 kuhlis adds up quickly. A planted 20-gallon layout is covered in the 20-gallon planted tank guide.

29 gallons and larger

A betta or dwarf gourami with kuhlis needs 29 US gal (110 L). Angelfish score 7/10 with kuhlis but push the tank to 90 US gal (341 L), because the angelfish’s own minimum is 53 US gal (201 L). The stocking calculator checks whether a planned mix fits a given tank.

Do kuhli loaches eat eggs and fry of their tank mates?

Yes, they may. Seriously Fish says kuhli loaches may prey on eggs or fry, though they do not hunt adult fish. That matters if you hope to raise fry from tank mates such as corydoras, which scatter eggs around the tank, or livebearers such as guppies and Endler’s livebearers, which drop live young.

Endler’s livebearers score 7/10 with kuhlis, partly because of water: the shared pH is only pH 7.0–7.0. Platies score 7/10 for the same reason. For breeding projects, a separate tank removes the egg risk entirely. Kuhli breeding itself is rated hard in our data; Seriously Fish describes only vague, unsupported spawning reports.

Two other habits affect tank planning. Seriously Fish says kuhlis like to dig and may bury themselves, so it recommends soft sand, and it warns they are known to jump, so the tank needs a tight-fitting lid. To test a species not listed here against kuhli loaches, use the species compatibility checker.