Species · Catfish & bottom-dwellers

Kuhli Loach

Pangio kuhlii

The little eel-like loach that hides by day and comes alive at night — peaceful and quirky, but it needs a group, soft sand to burrow in, and no gaps to escape through.

Difficulty: Beginner–IntermediateTropical community tank✓ Fact-checked care guide

Quick facts

Adult size~10 cm / 4 in
Minimum tank~55 L / 15 US gal — SeriouslyFish recommends a 60 × 30 cm base
Temperature23–26 °C / 73–79 °F (within the species range of 21–26 °C / 70–79 °F)
pH4.0–7.0 (soft, acidic to neutral)
Hardness0–8 dGH (soft water)
Filtration & flowCycled, gentle filtration; smooth sand substrate essential
DietOmnivore bottom-feeder — sinking foods, plus live/frozen; it needs its own food
SocialSocial — keep a group of at least 4–6
TemperamentVery peaceful and shy
Lifespan5–10 years

Overview

The kuhli loach is a slender, eel-like, peaceful bottom-dweller — a quirky, charming fish that spends the day hidden and emerges at dusk to forage. (Most "Pangio kuhlii" in shops are actually P. semicincta; care is the same.)

It is easy and long-lived, asking for three things people often miss: a group, soft sand to burrow in, and a tank with no gaps — kuhlis are escape artists.

Get the water right first. Almost every "my kuhli loach looks off" problem starts with the water. If you're new, readthe nitrogen cycle before anything else.

Water & tank

Kuhlis come from soft, acidic forest streams, so they prefer soft, slightly acidic-to-neutral water (pH 4.0–7.0, 0–8 dGH) at 23–26 °C / 73–79 °F. Give them soft sand (they burrow) and plenty of cover — wood, plants, leaf litter.

They're happiest in a group of 4–6+ in ~55 L / 15 US gal or more, and the tank must be well-covered: kuhlis slip through surprisingly small gaps, including filter intakes (use a guard).

Feeding

An omnivore that forages the substrate — it needs its own sinking food (pellets, wafers) plus live/frozen treats (bloodworm, daphnia); don't rely on leftovers. Feed after lights-out when it emerges.

Behaviour & tankmates

Peaceful with everything and a great community bottom-dweller. Keep a group or it hides constantly; in a confident group they come out far more, even by day.

Suit calm tankmates; avoid anything large or aggressive.

What to expect

Expect to see little at first — a new or lone kuhli hides almost entirely. With a group, cover, and sand, they gradually become bolder and are wonderful to watch snuffling through the substrate.

Myths, kindly busted

“One kuhli loach is fine.”

They are social — a lone kuhli hides permanently; keep a group of 4–6+ to see natural, confident behaviour.

“Any substrate works.”

They burrow and have delicate skin/barbels — use soft sand, not sharp gravel, and cover all gaps (they escape).

When to act

We triage, not diagnose — but these are worth a closer look (starting with a water test):

  • A kuhli constantly hidden even at night — usually too small a group or too little cover.
  • A missing loach — check for escapes and cover gaps/filter intakes; test water if one is lethargic or off food.

Sources & further reading

  • SeriouslyFish — Pangio semicincta (kuhli loach) — Adult ~100 mm SL; 60 × 30 cm base; temperature 21–26 °C / 70–79 °F; pH 4.0–7.0; hardness 0–8 dGH (soft); peaceful, social; burrower needing soft sand; the species usually sold as "kuhli loach".

Written & fact-checked by The Finfern Team against the sources above — kind, general guidance, not a diagnosis. If something looks wrong, test your water and, if it persists, contact a fish-savvy vet.

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