Kuhli Loach: Care, Diet, Lifespan, Tank size and More


The kuhli loach is one of the best options for diversifying a tank. This is due to their unique personalities that differ completely with most freshwater fish species.

They are peaceful bottom dwellers that clean out tanks in a very efficient way when the sun goes down. This sole reason is good enough to consider them.

That is, provided you have the right tank set up and you are up to the task of fulfilling their rather unique requirements.

Don’t worry! This guide provides you with everything you need to successfully keep the Kuhli Loach from tank size, water parameters, diets, tank mates common diseases and much more. 

By the time you are done reading it, you will know whether to give them a shot or not.

Kuhli Loach is native to southeast Asia. They are specifically found in rivers and streams of western Malaysia, Singapore, Thailand, Sumatra, Java and Borneo. 

The water bodies they occupy are mostly soft and slightly acidic.  The area is also characterized by slow-moving soft and slightly acidic water with sandy substrate. 

Kuhli Loach Care Snippet

  • Maximum fish size: 4 inch
  • Minimum tank size: 20 gallons
  • Aquarist Experience Level: Intermediate – Expert
  • Temperament: Peaceful
  • Temperature: 75 – 86 °F
  • PH: 5.5 – 6.5 pH
  • Hardness: 0-5dGH
  • Diet: Omnivore (Prefer Live Food)
  • Care Level: Relatively easy
  • Ideal tank mates: Neon Tetra, Ember Tetra, Chili Rasbora, Guppies, Cory Catfish, Sparkling Gourami, Honey Gourami, Mollies, et Cetra

Kuhli Loach Appearance

Kuhli loach looks a lot like an eel but what differentiates them from eels is the presence of pelvic fins and an independently separate dorsal, caudal and anal fins. 

True eels, however, lack pelvic fins and their dorsal, anal and caudal fins are merged creating some sort of paddle-like feature at their back. That feature is what distinctively differentiate them from the sea snakes.

Kuhli Loach fins are not so prominent which is why they are hard to see. Their dorsal fin is oddly located on the lower third of the body near the tail. Most fish have their dorsal fin around the middle of the body. 

Due to this, Kuhli Loach have a barely noticeable lateral line.

Majority of Kuhli Loach are multi-coloured. Their background color ranges between light pink to brassy yellow. The fish bottom is usually lighter than the rest of the body. 

The background color is followed by 10 to 15 dark stripes making the color pattern resemble that of a tiger. Some Kuli Loach have their stripes going round the entire body while others have theirs terminating at the belly.

They have what’s called a barbel which is a whisker-like sensory organ close to the mouth. They have 4 barbels and this feature enables them search for food in murky waters. 

It’s not that they can’t see with their transparent skin-covered eyes completely, those barbels are just to augment their food searching effort. 

Pangio kuhlii

As a defensive mechanism, they have a pair of sharp spines which they used to fend off predators. Conveniently, those spines are barely noticeable when the fish is relaxed but juts out as soon as they are threatened. The fish also uses them to harm attackers when they get eaten as kind of their last resort.

Their scientific name “Acanthopthalmus” in English means “prickle-eye” is influenced by that strange defensive mechanism.

Kuhli Loach have a very delicate body scales except on the head where there are no scales at all. As a result, their body is rather soft and very susceptible to disease. 

There are very subtle differences to notice between male and female kuhli loach especially when the females aren’t breeding. 

One thing to notice is that male Kuhli Loach have larger pectoral fins and a more muscular dorsal cross-section. 

During breeding times females become larger and you may even notice their ovaries through the skin before they spawn.

The black Kuhli loach

The black kuhli loach also known as the unbanded coolie or the chocolate kuhli loach, is a well-known variation of the kuhli loach that is also popular among hobbyist.

It has no difference in terms of size and behavior with the normal kind. From its name you can probably guess how the two differ. 

Rather than exhibiting tiger-like color pattern, the normal kind has its body covered in uniform black or dark brown color.

It’s surprising to learn that some hobbyists prefer the black kuhli loach. 

Black Kuhli Loach


In the wild, Kuhli loach grow to a maximum length of 5 inches. In captivity, their maximum size ranges between 3 to 4 inches long. 

Kuhli Loach Lifespan

Kuhli loach has an average lifespan of around 10 years. It’s surprising and remarkable for such a rather delicate fish to have the capability of living this long.

I mean they have the same lifespan potential as the rugged Jack Dempsey fish for example.

That said, if you want your Kuhli Loach to have a shot at realizing their full lifespan potential you have to provide;

  • Ideal water conditions.
  • Proper, healthy and diversified diet.
  • Ideal tank mates that will not stress them out.

Temperament and general behaviour

Kuhli Loach have a very reserved personality and aren’t at all attention seekers. That seems to increase when they are not in a group or among other similar species. 

Because of their peaceful nature, they can live with most passive freshwater species. However, they do respond if they get attacked. As previously mentioned they do have a defensive feature which they use to repel attackers.

They only use this feature when they must.

Kuhli loach likes to hang out in a group for a social reason but not in any coordinated manner which means they aren’t schooling fish

In the wild, they are mostly found in a group of dozen or more. In captivity, they can do well starting with a group of just 6. 

It’s highly encouraged you ensure this because keeping 1 or 2 kuhli loach in your tank will make them overly shy and very secluded.

Generally, Kuhli Loach activity level is quite low during day time. But as soon as the sun goes down they become very active. 

They are bottom feeders and in the wild spend most of their time is spent scavenging for food at the bottom of the water. That’s why you will hardly see them swimming in the upper areas of a tank.

They are curious creatures and have a habit of exploring all the corners of the areas around them.

In captivity, they behave pretty much the same. You will see them actively searching for food that sinks to the bottom of your tank.

They also like burrowing through the tank substrate which can be problematic near the tank’s filter.

I highly recommend you make the tank busy with crevices, caves and plants. This will help satisfy their curiosity. 

Tank size and Requirements

For keeping a single Kuhli Loach the recommended minimum tank size is 15 gallons. Since having just one is not advisable you can allocate 3 to 5 gallons of water per every loach you add. 

Being bottom-dwellers, they will appreciate tanks with more horizontal space. Be sure to have a tight-fitting lid for your tank.

Kuhli Loaches have a habit attempting to escape from tanks especially if they aren’t satisfied with the water condition.

After you have selected the appropriately sized tank, the next thing is equipping the tank will all the fish require to adapt easier and realise their full potential.

These requirements include aquascaping, substrate, tank decoration and filtration.

Kuhli Loach hiding in plants

Aquascaping for Kuhli Loach

Aquascaping entails providing their tank with adequate aquarium plantation. In the wild, Kuhli Loach are used to lots of vegetation, as such, they will require the same in captivity.

It’s highly recommended you make use of some easy-care plants such as Java Fern, Java Moss and the like in their tank.

Plants will help improve the water quality and at the same time provide them with lots of spaces they can hide in. 

Substrate for Kuhli Loach

In the wild Kuhli loach are used to sand as their substrate and they constantly borrow through it. Because of this, it’s the best substrate choice for their tank.

It comes with the advantage of being easier to clean, plus it won’t injure their delicate scales, unlike gravel for example.

The next best thing to have is smooth pebbles.

Tank decoration

Kuhi loach curiosity and shyness make it an absolute must to equip their tank with decorations such as pieces of rocks, driftwoods and caves. That is, if you want them to feel very much at home.

Without a busy tank, they won’t have many places they can run to during day time. This will make them stressed out. 

Pangio Kuhlii

Source: CC BY-SA 3.0


Kuhli Loach will require filters for their tank. The common issues many aquarists have had regarding this aspect is that they have habit of swimming to the filter.

Due to their curiosity and burrowing habit, they can swim to their death or at best get trapped in the filters.

Don’t fret! there is a very easy solution to this. You just need to cover the top of the filters with a very fine mesh.

Kuhli Loach Water Parameters

Most kuhli loach in the aquarium trade are wild-caught. So it makes sense to try and mimic the water conditions of their habitat very closely.

Coming from the slow-moving tropical rivers and streams, they will need warm temperatures. 

It has been established that Kuhli Loach does best when kept in a water temperature range of 73 to 86°F.

We have established that their rivers and streams are slightly acidic. Therefore, it’s recommended to keep their water with a pH of between 5.5 to 6.5 and maximum hardness of 5.0 dGH.

Food and Diet

Kuli Loach are scavenging bottom feeders and with this behavior they cannot be anything but omnivorous. In the wild, small crustaceans, small insects, larvae and plant detritus at the river bed are what make up most of their diet. 

In captivity, they conveniently scout around at night and eat up whatever they can find at the base of the tank.

If you have other fish in the tank (non-bottom feeders preferably), Kuhli loach are economic tank cleaners. You don’t have to worry about leftovers from other fish which could end up contaminating the tank.

In any case, these fish can not survive on just leftovers. The nice thing is that they’ll eat virtually all sort of fish food be it live, frozen, pallets or flakes.

Any food you buy needs to get to them. Like in case of pallets, you have to use sinking ones.

Pallets and flakes are cheap and readily available and should make most of their diet. Just make sure you use qualitative ones.  

The fact that they readily consume different foods doesn’t mean they don’t have preferences. Kuhli loach prefer meat-based diet. Feed them live meaty foods as a treat from time to time.

They appreciate protein-enriched diets such as artemia, bloodworms, daphnia, brine shrimp, micro worms and grindal worms. 

It’s a good idea to make their diet as varied as possible so that they can have all the nutrients their body need.

Its recommended you feed them several times a day as much as they can take in 2-3 minutes each time. Know their feeding capability so you can avoid overfeeding them.

Kuhli Loach Tankmates

Suitable tank mates will help your kuhli realised their full lifespan potential. Consequently, I start by pointing out the first and best tank mate for them. You guessed it- more kuhli loach. 

I have stated previously that they should be kept in a group of at least 6 (its not only schooling fish that always wants the company).

After you have satisfied this you can start searching for the next best species to add variety to your tank. 

Size and temperament are the most important factors to consider before choosing a tank mate.

Size-wise you want to avoid any fish that is big enough to stress your Kuhli Loach. They don’t need to be big enough to sip your fish before you drop them. 

It doesn’t matter if they are peaceful like discus or blue acara. Or aggressive like Jack Dempsey or Oscar. I recommend you avoid Cichlids and Arowanas all together.

As for the temperament, any aggressive species will not be a good tank mate for the Kuhli Loach.

This applies whether they are small like betta, Or big like the tiger shovelnose catfish or the rainbow shark

From this, you can deduce that the tank mate for kuhli loach will be a small non-aggressive fish. 

The species below have fit the requirements

If you want species that occupy the same tank region as the loach you can try the species below.

  • Otocinclus
  • Clown Pleco
  • Bristlenose Pleco
  • Cherry Shrimp

Some aquarists recommend keeping kuhli loach with snails but it’s not ideal because they can try to eat your snail.


Kuhli loaches are incredibly challenging to breed. That’s why most ones in peoples’ aquariums are wild-caught. That said, dedicated and experienced aquarist are having success breeding them.

They aren’t as stubborn to breed as the rainbow shark for instance.

It’s possible provided you have the proper tank set up, knowledge of their breeding habit and lastly, patience.

The first thing you need is make sure you have both male and female in the tank. Unfortunately, this can be a bit tricky because they look pretty much the same when they aren’t breeding.

A very subtle difference between the two is that males have slightly larger pectoral fin. You would have to very careful to notice this.

When they are ready to spawn, females become obvious. They become larger and in some instances, you can see through their skin and notice the ovaries.

As opposed to some fish, kuhli loach doesn’t require pairing before they can spawn. They are communal breeders.

You only need to have them in large groups and in a specifically designed breeding tank to increase the odds.

A specialized breeding tank for them is a tank that has a very similar condition to their natural breeding ground.

It needs to have a lower level of water. it also needs to be equipped with floating plants and rooted plants. They will also appreciate low light levels. 

Water hardness will need to be lowered a bit and the pH should be raised to 6.5

This will make them very comfortable. At this stage, the next thing they require is plenty of live foods. You will start to see the females becoming bigger and you might be able to see the eggs through the skin sometimes.

This is an indication that everything is going as desired. 

Once this happens, it’s highly recommended you pay close attention to your fish. Kuhli Loach are known for eating both their eggs and fries.

If they release the eggs and you leave them sticking around you may lose them altogether.

Look around floating plants in the tank because the laid eggs usually get attached to the underside of the plants. You may have to pay extra attention to find them. The eggs are bright green and can camouflage with some plants.

Move the adults kuhli loach back to the main tank as soon as you find the eggs.

The eggs will hatch within 24 hours. The little fry will consume the infusoria that is usually on the aquarium plants.

You can also feed them brine shrimp and flakes to supplement their diet.

Kuhli Loach Common Diseases

Kuhli loach are more susceptible to disease than most aquarium fish. Remember I mentioned they have very delicate body scales and their head does not have scale completely.

Consequently, they tend to have a very soft body that is easily penetrated by disease. Most fish are equipped with a hard scale which can protect them against diseases.

Another challenge that kuhli loach is subjected to is sensitivity to chemicals in the water. By this I mean they tend to get affected by medications that are used to treat fish disease. 

Some changes in water parameters can affect them negatively too. So you have to make everything as subtle as possible. 

Be careful when you are about to introduce them into a tank with existing fish. If there is a medication you are using on the fish your kuhli loach can get affected.

Ensure it’s safe and watch out for the water parameters.

The two most common diseases that are known to affect the kuhli loach are ich and parasitic infections.

Ich is a disease common to many freshwater aquarium fish and its caused by a parasite. Fish affected by this disease develop white spots on their skin much like sprinkled salt.

If not treated early, ich can cause further complications to your fish and even death. 

Ich spread easily in a tank and unfortunately, if a tank has kuhli loach, it attacks them first in most cases.

The parasitic infection however mostly causes what is called skinny disease. Fish affected by this disease in most cases start to lose weight even though it’s eating perfectly. 

You can lower their chances of getting a disease by keeping a top-notch water quality and feeding them very healthy diets as recommended.

And lastly, I highly recommend you quarantine any fish you are planning on adding to their tank. This will help make sure it isn’t carrying any disease that can endanger your Kuhli Loach. 

Commonly Asked Questions

Can black kuhli loach live with betta?

Kuhli loach can successfully live with bettas because they spend most of their time hiding. They also have no fins that bettas can nip at.

If you fashion a very good tank with lots of vegetation, pieces of rocks and driftwoods your betta probably won’t even know they are there. 

Kuhli loach are one of the few species that can coexist safely with betta, but make you use an appropriately sized tank.

Can black kuhli loach live alone?

Kuhli aren’t schooling fish but they still need to be kept in a group of at least 6 for social reasons. Keeping only one is highly discouraged.

Otherwise, it will become excessively shy and will completely avoid coming out in the open.

Can black kuhli loach live in a 5-gallon tank?

No! a 5-gallon tank is too small for a kuhli loach. As previously stated the recommended minimum tank is 15 gallons.


Kuhli loach can be a nice addition to community tanks of suitable mates due to their unique personality. They also make a great species only tank considering they come with requirements that can make your tank look epic.

I hope by now you have realised that keeping them will require a specially designed aquarium. They are delicate and at the same time full of potential.

You will need a spaciously enough tank that can house a minimum of 6 kuhli loaches(ideally).

The tank needs to be equipped with plants, driftwood and pieces of rock that will create abundant hiding spots for the loach.

You have to provide a substrate that won’t harm them and provide mesh so they don’t swim through the filters.

You need to mimic the natural water conditions of their habitat in the tank. They are sensitive to water parameters fluctuations and medications used to treat other fish.

For that, you need to evaluate any tank condition before adding them.

This pretty much sums of their care demand.

Giving how challenging it can be to provide and keep up with these requirements, Kuhli Loach are more suited for intermediate to experienced aquarists.

Own a Kuhli Loach? I will appreciate if you share any experience you think can benefit this guide.

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