Kuhli Loach: Species Overview

Category: Loach

Common Names: Kuhli Loach

Scientific Name: Pangio sp

Family: Cobitidae

Minimum Tank Size: 30 Gallons

Care Level: Moderate

Temperament: Peaceful

Max Size: 4 Inches

Temperature: 75-85 F

pH: 6.0-7.0

Tank Level: Bottom

Colors: Red, Tan, Brown

Diet: Carnivore

Breeding: Difficult

Bonhilda [CC-BY-SA-3.0]

Kuhli Loach Species Overview

The eel-like kuhli loach is a joy to watch in a tank. They’re also easy to care for, making them an excellent fit for new fish keepers.

Not many tropical fish species keep a tank sparkling clean, get along well with other fish, and add color to a tank. But that’s exactly what the kuhli loach does and why it’s so popular.

Nevertheless, kuhli loaches must have certain conditions to thrive. So, we’ll teach you the must-knows of caring for these fish so they can live long and healthy lives.

Distinguishing Features

Kuhli loaches look more like eels than fish, thanks to their slim, round bodies.

Adding to the eel appearance is the fact that it’s difficult to see their fins. But they do have a single, more prominent dorsal fin that sits back near their tail.

All kuhli loaches boast 10 to 15 brown or black stripes. But the colors that fill in the space between them vary depending on the fish’s genetic makeup.

Some of the most common color stripes on kuhli loaches include:

  • Light pink
  • Yellow
  • Orange

The lower belly of kuhli loaches is always lighter. In some cases, the stripes stop before the underbelly as well.

Kuhli loaches have a peculiar facial appearance, given that they have four pairs of barbels around their mouths, allowing them to navigate and search for food.

When kuhli loaches become spooked, they also have tiny, sharp barbel-like spines that protrude beneath their eyes.


Kuhli loaches call Southeast Asian countries home, including Malaysia, Singapore, and Thailand, to name a few.

They thrive in freshwater streams and rivers that have slow-moving currents. As a result, they enjoy clear water, although they can handle periods of cloudy water during monsoon season.

The nocturnal kuhli loach emerges from the sandy bottom, where it burrows to feast on food in the substrate at night.

These fish often live near the roots of aquatic plants, although they don’t depend on live plants for survival. Instead, they enjoy eating decaying plants and algae on the bottom of rivers and streams.


Unlike certain other species of loaches, kuhlis don’t grow very large. They can get up to five inches in their natural habitat, but they usually only grow three to four inches long in captivity.

That said, since many people catch kuhli loaches in the wild before selling them for captivity, you might encounter some five-inch adult fish.

Nevertheless, people commonly purchase these fish as juveniles when they’re only two or three inches long.

Male kuhli loaches have larger pectoral fins than females, and they also have a girthier dorsal cross-section. But aside from that, there’s little difference between genders regarding size except when females are spawning, and their bellies enlarge with eggs.


Kuhli loaches have an average lifespan of seven to ten years in captivity. That’s an impressive length of time, and you can expect your loaches to outlive many of their tank mates.

We’ve even heard people report that their kuhli loach lived for 14 years—longer than many dogs.

Your kuhli loach’s lifespan ultimately depends on a combination of their genes and the quality of care you provide them.


You can tell male and female kuhli loaches apart based on their tail shape and colors.

All female kuhli loaches have a straight tail. In contrast, males have an inward-curving tail.

Male kuhli loaches also have more black spots on their bodies. Furthermore, females are sometimes slightly paler in color than males, although the difference is often minimal.


Kuhli loaches are docile fish that won’t pick a fight with their fellow tank mates.

It’s more common to see a kuhli loach swim away from an aggressor, looking for a hiding spot, rather than fight it.

Furthermore, since these loaches are nocturnal, they rarely get in the way of diurnal fish. Instead, you can expect them to mind their own business during the day, sleeping until nighttime rolls around when they’ll be on the move for food.

Although kuhli loaches aren’t schooling fish per se, they often enjoy the company of other fish within their species. It’s common to see these fish playing together and sleeping near one another.

Males and female kuhlis are equally unaggressive loaches, so you don’t have to worry about pairing a certain number of females with males, like certain other tropical fish species.

Rmollik [CC-BY-SA-3.0]

Tank Parameters

If you’re ready to welcome kuhli loaches into a new or existing aquarium, it’s vital to know the tank parameters these fish require.

Minimum Tank Size

You should ensure you offer your kuhli loach a minimum of 20 gallons for one fish. If you’d like to put more than one kuhli in the tank, you’ll need to add a minimum of four to five extra gallons per fish.

That said, the more space you can offer your fish, the better. Kuhli loaches love being active, so the more area they have to roam around the bottom of their tank, the happier they’ll be.

And that leads us to this: Be sure to purchase a tank with a large bottom. Rectangular-shaped tanks are best for kuhli loaches.

Water Parameters

Once you’re the proud owner of an aquarium, you’ll need to prepare the water to receive your new kuhli loaches. Below are the parameters you should follow to ensure your fish stay healthy.


Kuhli loaches are from tropical climates, so they prefer warm water between 73–86°F.

It’s best to attach a thermometer to the side of your aquarium. That way, you can monitor the temperature in case your heater malfunctions.


You’ll need to keep your kuhli loach’s pH between 5.5 and 6.5.

That’s a mildly acidic pH, as neutral water is 7.0. If you have water that’s higher than 5.0 dGH, you should also take action to soften it before introducing your loaches to it.

Luckily, testing and fixing your water’s makeup is easy and inexpensive, thanks to testing kits and chemicals that can alter the pH and water hardiness.


As freshwater fish, kuhli loaches don’t require salt in their tank. Placing them in a saltwater aquarium will kill them.

That said, it’s safe to occasionally add small amounts of aquarium salt to your loach’s tank to boost their immune system.

Salt can also be an effective tool for killing certain parasites and infections from bacteria and fungi.

Tank Setup

With your water ready to go, the final step in preparing to receive your kuhli loaches is to set up the visible parts of their tank.


Kuhli loaches love to burrow, so providing them with a soft substrate like fine sand is vital. Smooth gravel can also work well.

These fish have delicate skin due to their small, fine scales. Therefore, using heavier or jagged substrates can cut up their bodies, creating the massive potential for infections.


Your kuhli loaches will appreciate having decorations, as it’ll give them a hiding spot.

These fish spook easily, so having quick access to sunken logs with holes they can hide in or piles of rocks will reduce their stress levels.

Such items, including artificial caves, are an excellent way to mimic the kuhli loach’s natural environment and add aesthetically pleasing touches for the fish keeper.


Your kuhli loach will appreciate having living plants in their tank. These plants serve as both hiding places and food from fallen debris.

Peat moss and java ferns are excellent plant choices for kuhlis.

When setting up plants in your tank, anchor them well. Otherwise, your kuhli loaches may accidentally dig them up when they burrow.

Finally, keep in mind that you shouldn’t pack your tank so full of plants and decorations that it leaves little room for your kuhlis to burrow in the substrate.


As nocturnal fish, kuhli loaches don’t need or want lots of light.

In the wild, these fish tend to live in areas with dense vegetation on top of the water. So, little sunlight reaches the bottom of the riverbed where they live.

As a result, purchasing a lamp is okay, but you should keep it in a dim setting. Furthermore, be sure to turn the light off at night so that you don’t disrupt the kohli’s nocturnal habits.

If you’d like to watch your kuhli loaches swim around at night without disturbing them, installing a red or blue light in their tank is an excellent option.


Kuhli loaches serve as a mini-filter for aquariums, as they eat algae and debris at the bottom of the tank. But don’t make the mistake of thinking they can replace true filter systems.

Therefore, you must install a filter system fit for your kuhli loach’s tank size.

The issue with filters is that the inlet tube is often large enough for kuhlis to swim into and become stuck. Therefore, you should use a sponge or filter material to plug the entranceway.


Since kuhli loaches enjoy water temperatures above the room temperature for most homes, purchasing a heater is a must.

We recommend setting your heater to the upper 70s or low 80s so that you stay in the middle of the 73 to 86°F range that kuhli loaches require.

Should you ever need to adjust the temperature in your kuhli loaches tank, such as to accommodate the water parameters of new tank mates, it’s crucial to change the temperature gradually so that your fish doesn’t go into shock.


Kuhli loaches aren’t picky about their food. These omnivores will devour everything from minuscule pieces of debris in the substrate to algae on the side of the tank and small crustaceans.

But you shouldn’t rely on algae and debris alone to feed your kuhli loach. Instead, below are some foods you should give them regularly:

  • Sinking pellets
  • Brine shrimp
  • Water fleas
  • Bloodworms

When contemplating food for your kuhli loaches, ensure it’ll reach the bottom of the tank. Fish flakes and freeze-dried foods take longer to sink, sometimes causing them to deteriorate before arriving in your loach’s mouth.

You should feed your kuhli loaches two times per day.

During feedings, observe how much they eat in two to three minutes. Make a note of that for next time, for that’s the correct amount of food to give them.

If you overfeed your kuhli loach by a lot, scooping out the excess food is best to prevent waste buildup. We know that’s not the most convenient method, though, which is why learning to eyeball the amount of food they need is ideal.


You’ll need a combination of patience and luck to breed kuhli loaches, given that it’s a challenging process without using hormone injections.

For starters, you’ll need to wait until the females are at least two years old, which is when they reach sexual maturity.

Once you’re ready to breed your fish, you don’t need to pair them off. Instead, simply adjust their water conditions (assuming no other fish species are in the tank).

The ideal water conditions for breeding kuhli loaches are as follows:

  • Lower water levels
  • Lots of live floating plants
  • Dim light
  • pH of 6.5

You’ll also want to begin feeding your fish a diet high in protein. Live food is best.

With any luck, the females will begin to expand in size as their bellies fill with eggs. Once the female is ready to give birth, she’ll lay her eggs, and the males will spawn them.

The eggs typically attach to plants in the tank. But these hiding spots are no match for their parents, who will happily eat their offspring if you give them a chance.

For this reason, moving the eggs to a separate tank as soon as you see them is vital.

It only takes 24 hours for the vibrant green kuhli loach eggs to hatch. At that point, you can start feeding the baby fry crushed flakes and tiny brine shrimp.

Common Diseases

Since kuhli loaches have such small, thin scales, it’s common for them to suffer from diseases easier than many other species of tropical fish.

That said, they don’t have species-specific diseases. Instead, below are some of the most common ailments they can catch from other tank mates or due to poor water conditions.


Ich is arguably the most common disease in kuhli loaches. It’s a parasitic infection that covers these loaches in small white spots from the parasite burrowing beneath their scales.

These loaches get ich from other infected fish. Treatment involves moving them to a quarantine tank, treating the water with anti-ich medicine, and increasing the water temperature.

You’ll need to keep up treatment after the ich appears to leave, as these parasites have a long life cycle and often live on the substrate.

Hole-in-the-Head Disease

Hole-in-the-head disease is from the Hexamita parasite. It causes indents around kuhli loaches’ heads, making them look like they have holes.

Treating hole-in-the-head disease is challenging, but you can try adding an antibiotic to the tank.

Luckily, most kuhli loaches can live long lives despite this disease.

Fin Rot

Fin rot results from a bacteria or fungus eating away at your kuhli loach’s fins.

Signs of fin rot include a white color around the edges of their fins, fins that stick together, and a stringy appearance.

You can treat fin rot by adding antifungal or antibacterial medicine to the water. Luckily, fin rot rarely does permanent harm to kuhli loaches if you catch it early enough.

Anchor Worm

The parasitic anchor worm has a whip-like tail that it uses to clasp onto a kuhli loach’s mouth.

Anchor worms rarely harm the quality of a kuhli loach’s life. But if they seem to bother your fish, you can try to pull them off gently.

If you opt for this route, treat the water with an antibiotic for preventative purposes.

Mouth Fungus

Mouth fungus is an appalling condition where your kuhli loach appears to have a stringy cotton ball emerging from its mouth.

That’s the fungus, and it comes from the Mycobacterium species.

Mouth fungus is challenging to treat. You should apply antibiotics to the water, perform frequent water changes, and ensure ammonia levels remain intractable.

Potential Tank Mates

The best tank mates for kuhli loaches are more kuhli loaches. These fish tend to feed off each other’s energy, becoming more active when there are five or more in a tank.

That said, a strictly kuhli loach aquarium makes for a boring tank during the daytime.

Thankfully, since kuhli loaches are so friendly, you can add many different fish species to their tank. Some of the best tank mates for these loaches include:

  • Danios
  • Tetras
  • Rasboras
  • Corydoras

Aside from corydoras, the fish mentioned here live in the middle to the top part of the tank. So, it’s unlikely your kuhli loaches will come in contact with them often.

That’s good news for your loaches, given how they’re skittish.

You can even add cherry shrimp to a kuhli loach’s tank. Just be sure the shrimp are large enough; loaches love eating zooplankton in the form of baby shrimp.