Loaches

Loaches are social bottom dwellers with strong personalities, from noodle-shaped kuhlis to flow-loving hillstream species. Most want company, smooth substrate and places to hide. Profiles list group size, tank size and the conditions each species needs.

Tank size: 11–127 gal; 11 gal (40 L) to 127 gal (480 L); half the list needs 24 gal (90 L) or more
Temperature: 68–79°F; 20–26°C, most of the list
pH: 6.5–7.5; Most of the list
Difficulty: 9 easy; 98 medium · 33 difficult
Temperament: 67 peaceful; 67 mostly peaceful · 6 aggressive

140 species

The main kinds of loach

Loaches are several families that share a bottom-dwelling habit and little else. Kuhli loaches and their Pangio relatives are eel-shaped sand burrowers that hide by day and come out at dusk. Botiid loaches, the clown, yoyo, zebra and dwarf chain loaches, are the active shoaling snail-eaters, and a few of them, including the sun loach and Leconte's loach, are aggressive. Hillstream loaches are flat, sucker-bellied fish from fast cool streams and need flow, oxygen and biofilm rather than a tropical community. Stone loaches such as the rosy and zipper loaches are small stream fish, with the sumo loaches as the solitary, territorial exception and the giant stone loach, a 22 inch (55 cm) cold-water predator, as the outlier. The weather loach and the spined loach are cold-water fish for unheated tanks and ponds.

Groups, sand and hiding places

Most loaches are social and turn nervous or reclusive alone; keep the shoaling species in fives and sixes at least. Burrowers such as the kuhli and horseface loaches want fine sand, and every loach wants cover: caves, pipes, wood and plant thickets. They are also escape artists. Kuhli loaches find gaps in lids and filter intakes, so cover both, and a loach that vanishes has usually burrowed or wedged itself somewhere rather than died.

Clown loaches outgrow the tank they were sold for

The clown loach is sold at 2 inches (5 cm) and reaches 12 inches (30 cm), wants 75 gallons (285 liters) and a shoal, and lives for decades. The redtail loach and the banded tiger loach reach 10 to 12 inches (25 to 30 cm) on the same footprint. The chameleon loach reaches 10 inches (25 cm), wants 105 gallons (400 liters) and is aggressive. For the same shoaling character in a smaller tank, the yoyo loach stops at 6 inches (16 cm) in 40 gallons (160 liters), the zebra loach at 3.5 inches (9 cm) in 35 gallons (140 liters), and the dwarf chain loach at 2.5 inches (6 cm) in 20 gallons (75 liters).

Hillstream loaches are a cool, fast-water project

Hillstream loaches come from streams that run cool and hard over rock, and they are marked medium or difficult in the catalog for a reason. Most list 61–75°F (16–24°C), well below a heated community tank; the Borneo suckers are the warm end at 72–79°F (22–26°C). All of them need strong flow, high oxygen and a standing crop of algae and biofilm to graze; a new tank starves them. Set up a dedicated river tank with a powerhead, smooth rocks and strong light, and they are rewarding. Drop one into a 82°F (28°C) community tank and it will not last.

Loaches for a small tank

Several loaches suit a 10 to 20 gallon (40 to 75 liter) tank. The rosy loach stays around 1.2 inches (3 cm) and shoals in mid-water more than most loaches. The dwarf chain loach and the dwarf horseface loach stay small and social. The kuhli loach itself is fine in 20 gallons (75 liters) in a group of five or six, and the fire-eyed, mango and dwarf lizard loaches are true nano fish for a mature tank with fine food.

By the numbers

Smallest

Largest

Easiest to keep

Most peaceful

Fits a 20 gallon tank

Fits a 30 gallon tank

FAQ

Common questions

What types of loaches are there?

Kuhli and other Pangio loaches, the botiid loaches (clown, yoyo, zebra, dwarf chain), hillstream loaches, stone loaches such as the rosy and zipper loaches, and the cold-water weather and spined loaches. The section above walks through what each group needs.

How many loaches should be kept together?

For the social species, five or six at least; clown, yoyo and zebra loaches and kuhlis all do poorly alone. The sumo loaches, the zodiac loach and the fork-tailed loach are the exceptions and are kept singly.

Do loaches eat snails?

The botiid loaches do: yoyo, zebra, skunk and clown loaches all eat small snails. Kuhli, hillstream and stone loaches do not.

Do loaches need sand?

The burrowers do. Kuhli and horseface loaches want fine sand; botiids and hillstreams are fine on smooth gravel or rock as long as there is cover.

What size tank do kuhli loaches need?

20 gallons (75 liters) for a group of five or six, with sand and hiding places.

Why do my loaches disappear?

Kuhlis and other burrowers hide by day and under the substrate. Check filter intakes and lid gaps before assuming the worst; they come out at dusk and at feeding time.

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