Loach: Care Guide & Species Profile

loach fish in a tank

Loaches are a group of small, freshwater fish that belong to the superfamily Cobitidae. There are more than one thousand loach species known today, and most loaches live in Eurasia and Northern Africa.

Some of the most common loaches are kuhli loaches, clown loaches, and hillstream loaches.

Loaches have a unique appearance, with small, narrow bodies and at least three pairs of whisker-like barbels at the mouth.

Loach Facts & Overview

Loach fish swimming on rocks in a decorated tank

Scientific order:Cyprinidae
Common namesLoach
Distribution:Europe, northern Africa, and central and Southeast Asia
Size:2.5–12 inches or more, depending on the species of loach
Life expectancy:5–10 years
Color:A variety of colors, including yellow, brown, orange, black, and silver
Minimum tank size:20–150 gallons, depending on the species of loach
pH:5.5–7.8 pH
Hardness:3–10 dGH
Care level:Easy

Origin & Distribution

The loach’s superfamily name, Cobitidae, was a term that Aristotle used to refer to “small fishes that bury.” This name was described in Swedish zoologist Carl Linnaeus’s 1758 10th edition of Systema Naturae. The pointface loach was the first loach to be recognized in 1940.

Most loaches are native to southern and central Asia, and several species of loach are found in Europe and Africa. The most popular aquarium loaches are Asian loaches, such as clown loaches and kuhli loaches.

Types of Loaches & Appearance

Pair of loaches swimming near rocky substrate

There are more than 1200 species of loach known today. Some of the most popular loaches amongst aquarists are listed below.

Yoyo Loach

Yoyo loaches are also known as Pakistani loaches. These interestingly colored fish are white with curvy black lines on their bodies in the shape of letters Y and O. Yoyo loaches also bob up and down in the water like yoyos. They have mild temperaments when in schools of at least six.

Kuhli Loach

Kuhli loaches are nocturnal bottom-dwellers with peaceful temperaments and laid-back personalities. They have long, eel-like yellow or white bodies with thick, black bands. They grow up to 4 inches as adults, with a lifespan of up to 10 years.

Clown Loach

Named for their coloring, clown loaches are pale orange with black spots. They reach up to 8 inches in length. Unlike most loaches, clown loaches are diurnal fish (active during the day). They prefer to live in schools of six or more, and they do best in temperatures of 80°F or higher.

Hillstream Loach

Hillstream loaches are native to fast-moving freshwater streams and rivers in Asia. They have an unusual appearance, because their bodies are flat with wide fins. These fish are taupe-colored with mosaic-like black patterns. Hillstream loaches are calm, docile fish that should be housed with at least three other fish of the same species.

Dojo Loach/Weather Loach

Dojo loaches are also known as weather loaches because the fish display excited behavior when a storm approaches. These fish are one of the longest loach species, reaching up to 11 inches in length as adults. They’re available in colors including golden yellow, brown, and albino. Dojo loaches thrive in temperatures below 80°F.

More Loach Types

While these loaches are less common in home aquariums, they also make peaceful, sociable additions to a freshwater tank.

  • Zebra loaches: White or pale yellow bodies with thin black stripes. Grow to 3.5 inches (9 cm) long. Do best in schools of six or more and can handle a range of water parameters. Laid-back, outgoing personalities.
  • Java loaches: Similar appearance to kuhli loaches, without the black markings. Pale or dark brown elongated bodies. Grow up to 3 inches in length. Peaceful community fish that enjoy scavenging food at the bottom of the tank.
  • Sumo loaches: Colorful fish with eel-like gray-brown bodies, patterned dorsal fins, and bands of red, yellow and orange from the mid-section to the tail. Hardy, beginner-friendly fish that reach up to 3.5 inches in length.
  • Dwarf chain loaches: Yellow or stone-colored bodies with black chain-like patterning. Reach up to 2.5 inches in length as adults. Active, playful fish that swim in the bottom and mid-section of the tank. Do best in groups of six to ten.
  • Polka dot loaches: Similar appearance to yoyo loaches but smaller and more peaceful than the yoyo loach. Pale bodies with dark brown or black polka dot markings. Reach 4 inches in size. Outgoing, fish with fun personalities.
  • Rosy loaches: One of the smallest loach species, reaching 1.2 inches in length. Pinkish-orange bodies with a horizontal black stripe from the gills to the tail. Social fish that must be kept in schools of at least eight. Ideal for micro-aquariums.

Loach Behavior & Compatibility

Loaches are peaceful fish. Not all loaches are schooling fish, but most loaches are sociable and prefer to be housed with companions. Some loaches, like kuhli loaches, are shy fish that only come out of hiding at night.

The majority of loaches are nocturnal. Clown loaches come out during the day, making these fish a popular choice among aquarists.

Some loach species swim in the middle of the tank, while other species are bottom-dwelling, and spend a lot of time scavenging for food in the substrate.

Loaches are curious fish that appreciate plenty of caves and plants to explore in. The more active loach species, like polka dot loaches and dwarf chain loaches, need lots of space to swim freely.

A peaceful fish that don’t like to cause trouble, a loach does well in community tanks with other loaches and peaceful fish.

Tank Mates

Loaches are peaceful fish that are best housed with other non-aggressive, small fish species. Ideal tank mates for loaches are fish that occupy the upper portions of the tank, giving loaches plenty of space to swim around in the bottom of the aquarium.

You shouldn’t house loaches with big, aggressive, or territorial fish, like arowanas and cichlids. Fin-nippers like angelfish, Chinese algae eaters, and tiger barbs are known to bully loaches, and shouldn’t be added to your loach tank.

Don’t keep loaches with snails, because the loaches will view the snails as food.

Some of the best fish to house with loaches are:

  • Other species of loach — The majority of loaches are peaceful and enjoy one another’s company. After buying a school of loaches, consider adding other types of loach to the tank. Make sure you have several of the same species of loach before buying different species.
  • TetrasCardinal tetras and neon tetras are non-aggressive and non-territorial, making them suitable tank mates for rasboras. Growing up to 1.5 inches in length, neon tetras and cardinal tetras prefer the middle of the tank, and do best in schools of six to ten.
  • Danios — Danios are beautiful, lively fish, and are suitable for beginner aquarists because of the fish’s low care needs. Like loaches, danios are peaceful and prefer to be kept in groups of six or more.
  • Corydoras — Reaching up to 2.5 inches when fully grown, corydoras are peaceful bottom dwellers that spend a lot of their time foraging for food. Corydoras prefer to live in groups of at least five.
  • Honey gouramis — Peaceful gourami species, like honey gouramis, are good tankmates for loaches. Honey gouramis are shy fish that prefer the company of at least one other fish of the same species. As pelagic fish, honey gouramis spend most of their time swimming in the middle or the surface of the aquarium.

Male vs. Female Loaches

Male and female loaches have different body types from one another, making it easy to tell the difference between the two genders.

Female loaches are rounder and plumper than males. A female’s belly becomes even rounder than normal when the female is carrying eggs.

The tail is another feature that varies between male and female loaches. The tail of a female loach has a straight top, while a male loach’s tail is curved inward.

Male loaches are more streamlined than females, but males have more muscular upper bodies than females.

There is no difference in behavior between male and female loaches.

Loach Tank Setup

Loach planted tank set up

Loaches have no head scales and faint body scales, which makes the fish more susceptible to disease. Keeping the water in the tank clean and well-oxygenated is essential for a healthy fish. Caring for loaches is easy if you know how to look after the fish.

In the wild, loaches live in clear rivers and streams with slow-to-fast-moving currents. Some species of loach, such as clown loaches, migrate into flood plains during the monsoon season. You should maintain the right water parameters and add suitable decorations to your tank to make your loaches feel comfortable in captivity.

Tank Size

The ideal tank size for loaches depends on which species of loach you buy. For instance, a group of five clown loaches needs a tank size of at least 150 gallons or roughly 30 gallons of water per loach. Clown loaches are one of the biggest loach species and require a bigger tank compared to other loaches.

Kuhli loaches are a good option for people with limited space for a tank. These loaches require a minimum tank size of 20 gallons. You should make sure there’s at least 3 gallons of water per loach.

A good mid-range option is the yoyo loach. A group of four yoyo loaches requires a 40-gallon tank, or a minimum of 10 gallons of water per fish.

Water Temperature, Hardness, & pH

Even though loaches are hardy fish, you should maintain stable water parameters to reduce the risk of disease in your tank.

Different loach species have different water requirements. The below-recommended parameters are broad to reflect the requirements of the entire loach group. Check the specific requirements of your chosen loach species before you buy the fish.

  • Temperature: 75.0–86°F
  • pH Range: 5.5–7.8
  • Hardness Range: 3–10 dH

Maintaining optimal water conditions will keep your loaches happy and healthy.

Loaches require plenty of water movement, and a good-quality filter with a turnover of at least ten times per hour can achieve this.

An under-gravel water filter can be used to oxygenate the water and clear waste. Place a cover over the inlet and outlet pipes to prevent loaches from being sucked into the filter.

Substrate and Decoration

Use a combination of soft sands and smooth pebbles to mimic the riverbed in your fish’s wild habitat.

If you want to see your loaches swimming during the day, use floating plants like java moss and water spangles to subdue the lighting.

Submerged plants, like the Amazon sword, provide the underwater vegetation that loaches are used to in the wild. Java fern and cryptocoryne are two other suitable plants for loach tanks. You can recreate leaf litter in the tank by spreading peat moss on the substrate.

A couple of pieces of driftwood, caves, twisted roots, and large, smooth rocks can also be used as tank decorations. These items give your loaches more opportunities for playing and hiding.

A firm lid or cover is essential for preventing loaches from jumping out of the tank.


Loaches are easy to care for, but these fish are susceptible to ich because of their lack of scales. Maintaining stable water parameters is an essential aspect of loach care. Keeping on top of regular water changes and tests is also vital for a loach tank because loaches are sensitive to nitrates.

Diet & Feeding

In the wild, loaches feed on water-dwelling snails, worms, and crustaceans. When these invertebrates aren’t available, loaches feed on algae and decaying plant matter.

You should feed loaches a variety of foods to mimic the fish’s varied diet in the wild. Algae wafers and shrimp pellets provide a good source of nutrients for loaches. Frozen foods like bloodworms and shrimp are an important part of a loach’s diet, but you should limit these foods to several feedings per week.

Snails are a loach’s favorite food, and some aquarists set up a separate tank to breed snails as live food for their loaches.

Feed loaches a pinch of food twice per day. There should be enough food for your loaches to eat within two minutes. Clear away any waste after feeding has finished.


Loaches are susceptible to several common bacterial and parasitic diseases, including:


Loaches are particularly susceptible to ich, also known as white spot disease, because the fish have small or no scales. A loach with ich has salt-like white spots on the gills and fins, and the fish will scratch against hard surfaces in the tank.

Other ich symptoms are weight loss and a loss of appetite. Quarantine the affected fish in a tank with identical water parameters to prevent ich from spreading to other fish. Increase the water temperature in the quarantine tank by two degrees and add anti-parasitic medication to the tank.

Skinny Disease

Skinny disease is the second most common disease in loaches. A loach with skinny disease will lose weight even though the fish appears to be eating normally. Skinny disease is caused by internal parasites or bacterial infections. Treat skinny disease with medications recommended by your local aquatics seller or veterinarian.

You can reduce the potential for disease by taking caution when introducing loaches to an established tank. As long as water parameters remain stable, your loaches should remain healthy.

Breeding Loaches

Breeder holding two clown loaches

Loaches aren’t easy fish to breed because many loach species migrate before spawning. If you’re a beginner aquarist, you shouldn’t consider breeding these fish. However, if you’re experienced in fishkeeping, you can attempt to breed loaches in captivity.

To breed loaches, you will need a sexually mature pair of fish. It takes 12 to 18 months for a loach to become sexually mature.

Loaches over two years old are most likely to breed.

Follow the steps below for the best chance of breeding success.

  • House the male and the female in separate tanks and feed both fish nutritious foods.
  • The female should grow larger, indicating the production of roe. Place the male and female in a tank with excellent water quality, a temperature of 77.9-79.7°F, a pH of 6.2-6.4, and lots of plants. These tank conditions are optimal for breeding.
  • Wait for the female to release her eggs and the male to fertilize the eggs. This could take several days. Fertile eggs are pink, while infertile eggs are brown.
  • Remove the male and the female to prevent the fish from eating the eggs.
  • The eggs will hatch after 24 hours.
  • Feed the fry live cultivated infusoria. Wean the fry on tubifex worms, baby brine shrimp, and ground-up fish flake food. Perform partial water changes every day.

If the first pair of loaches don’t breed successfully, repeat the process with a different pair.

Should You Get a Loach for Your Aquarium?

You should get a loach if you can provide a large decorated space for a bottom-dweller with peaceful fish tankmates. Keep the water parameters stable and provide a variety of foods and tank decorations to help the loach stay happy in captivity.

You shouldn’t get a loach if you already house other burrowing fish or aggressive fish in your tank or if you’re using your tank to breed snails.

Loaches are curious, sociable fish that can live happily in a variety of tanks. They’re easy to care for, and they would be a low-hassle fish to add to an aquarium. Loaches are a fun addition to a home aquarium because of the fish’s unique appearance and peaceful behavior.

About Robert 468 Articles
Robert Woods is the creator of FishKeeping World, a third-generation fish keeper, and a graduate in animal welfare and behavior. He is also a proud member of the Association of Zoos and Aquariums, the Marine Aquarium Societies of North America, and the Nature Conservancy.

1 Comment

  1. Sandy says:

    I have a 29 gal. established tank. I have 2 zebra loaches and 1 yo loach that I thought was a zebra loach when I bought it. That’s all the fish I have. Is my tank to small to get another yo yo loach?

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