The Chinese Algae Eater is a freshwater fish that comes with a mixed reputation. Some aquarists think they’re very aggressive, others believe they only eat algae, and a few mistake them for another species entirely!

Because there’s so much confusion out there, we thought it would be a good idea to create this guide to help set the record straight.

In it, you’ll learn everything you need to know about the Chinese Algae Eater. Care tips, average size, aggressive tendencies, food, and tank mates are all in here!

Species Summary

The Chinese Algae Eater is a unique fish that you wouldn’t expect to be a popular choice among aquarists. They’re not particularly colorful and tend to be solitary creatures. However, their penchant for eating algae makes them a great choice for those who want to keep their tank clean.

Despite their name, these fish are most commonly found outside of China. They are native to the Chao Phraya basin and can be found living in rivers throughout Laos, Vietnam, and Thailand.

Scientifically, these fish are known as Gyrinocheilus aymonieri. But, they go by many names in the aquarist community. The two most popular are the Honey Sucker or Sucking Loach.

Whatever you call them, these fish can be a bit of a challenge to care for. Not only do they require good water conditions, but their temperament and habits can change as they get older.

Lifespan

The typical Chinese Algae Eater lifespan is around 10 years. This makes them a fish that’s better suited for aquarists who are interested in making a reasonable commitment. Casual hobbyists might do better owning a species with a shorter lifespan.

As always, many factors can contribute to their overall lifespan. Some of the biggest are water conditions and diet. The state the fish was in when you purchased them matters a lot too.

Appearance

As we mentioned earlier, Chinese Algae Eaters don’t have the vibrant looks of other fish. They have a relatively muted color and pattern. Sometimes they’ve mistaken for the Siamese Algae Eater, but you can tell the difference when you pay attention to the details.

Most specimens have a golden or pale brown body. Typically, the fish’s belly is lighter. Accompanying the base color is a dark black stripe.

Gyrinocheilus aymonieri resting on the substrate

This stripe runs horizontally across the entire length of the fish. For some fish, the stripe is broken up into smaller dots. Either way, black coloration is present in almost all specimens.

Some color mutations do exist, but they are rare.

In terms of shape, the fish have long slender bodies and very small fins. One unique feature is the dorsal fin. They have a small dorsal fin with several firm rays, giving it a somewhat spiky appearance.

Perhaps the most noteworthy physical feature of the Chinese Algae Eater is their mouth. These fish have a large mouth and sizable lips. The mouth is used to create a small vacuum against smooth surfaces. If your fish is latched onto the glass, you can even see their mouths moving subtly to create the suction power.

Chinese Algae Eater Size

The average Chinese Algae Eater size can get around 10 or 11 inches in length when fully grown. Sometimes in captivity, they can be a lot smaller (usually around 6 inches) if you place them in the minimum recommended tank size.

Some home aquarists have been able to get theirs to surpass this size, but those instances are uncommon. Regardless if you want to maximize the size of your Chinese Algae Eater or not, you should give them plenty of room (more on that later).

Chinese Algae Eater Care

Chinese Algae Eater care is something that anyone can handle. You don’t need a ton of experience to keep this species healthy. In fact, these fish are quite hardy and can do well in various conditions. When you consider the fact that they constantly eat algae in your tank, there’s not much you have to do to keep the fish entertained!

Nevertheless, you need to set them up with a great habitat and stay on top of water quality to stave off stress or disease. Plus, some issues could make these fish challenging for some aquarists. Here are some care guidelines you should be wary of.

Tank Size

So how big should your tank size be for a Chinese Algae Eater? At the very least, these fish need 30 gallons. That number is assuming you only have one Chinese Algae Eater in your aquarium.

Author Note: While you can see success with 30 gallons, we always recommend getting a slightly bigger tank (aim for 50 gallons). These fish can get pretty big, and a larger tank will help them reach their full potential while ensuring there’s plenty of algae to feed on.

Water Parameters

One of the biggest mistakes new owners make when caring for Chinese Algae Eaters is not staying on top of water conditions. Contrary to popular belief, these fish will not stay healthy in a dirty tank.

You want to aim for overall clean water, with some controlled algae so these fish can snack throughout the day.

This means the water parameters need to be maintained and monitored consistently to ensure that no harmful shifts occur. Invest in some testing equipment and analyze the water regularly to ensure that conditions fall within the following parameters.

  • Water temperature: 74°F to 80°F 
  • pH levels: 5.8 to 8.0 (6.5 to 7.5 is the sweet spot)
  • Water hardness: 8 to 10 KH

What To Include In Their Tank

Like any fish, the key to giving your fish an enriching environment is to mimic their natural habitat. Chinese Algae Eaters are found in rivers throughout Asia. These rivers are on the warmer side and have tons of places for the fish to hide in.

Chinese Algae Eaters spend most of their time being bottom-feeders and scavenging for food in the lower part of their habitat. This means you should be paying special attention to this area of your tank.

You can cover the bottom with a fine sand substrate. Small gravel works well, too. However, sharp pieces of gravel can injure the fish as they swim.

Place large rocks in the sand. You can also utilize artificial caves to give your fish places to hide.

We recommend choosing a few smooth flat rocks. These rocks will collect aquarium algae over time. Chinese Algae Eaters will then latch onto the smooth surface of the rocks to clean them.

At the top of the tank, make sure that you have a tight-fitting lid. With their powerful sucker mouth, Chinese Algae Eaters are notorious escape artists. Invest in a lid that latches closed to prevent any unwanted surprises.

Standard lighting should be fine for these fish. They like a lot of light. While they spend time at the bottom of the water column, you don’t need powerful lights to keep them happy. Standard fixtures are more than enough to give them the light they need.

As for filtration, high-powered equipment is essential. These fish are particularly sensitive to nitrates, so your filter needs to be efficient enough to keep levels low. It’s also a good idea to perform water changes regularly to avoid stress.

Author Note: A lot of aquarists forget about water flow. The rivers that these Chinese Algae Eaters occupy are quite fast. In these waters the fish stay stationary in their habitat by latching onto smooth rocks.

You can recreate a powerful water flow with a good pump. Direct the outlet towards the side of the tank to keep the water circulating at all times.

Diseases To Watch Out For

There aren’t any species-specific illnesses that you have to worry about with Chinese Algae Eaters. But, that doesn’t mean that your fish are immune to health problems.

They can experience common conditions that affect all freshwater fish, such as Ich. Ich is caused by stress, which is usually a direct result of poor water conditions. Again, maintaining those parameters from earlier is crucial.

Chinese Algae Eaters are also prone to bloat. This isn’t just a cosmetic problem and should be taken seriously. Bloat from overfeeding can lead to serious digestive problems if it isn’t addressed.

Food & Diet Recommendations

The interesting thing about Chinese Algae Eaters is that their diets tend to change as they get older. When they are young, these fish have no problem feeding off algae.

Many owners don’t even feed them because they get ample nutrients from cleaning up the tank. Unfortunately, their appetite for algae wanes as they get bigger.

Eventually, your fish will want some protein. In their natural habitat, they’ll often feed on insect larvae. You can quench their hunger for protein with bloodworms or brine shrimp.

Sometimes, you can reinvigorate their interest in algae with wafers. Every fish is different, so make sure that you can keep an eye on your fish. You should consider other food options if you notice that they are not eating algae as much.

Author Note: When experimenting with feeding it’s important to make sure that you’re not compromising the water quality. Uneaten food can quickly raise the ammonia and nitrate levels in your tank (which is not good).

Temperament & General Behavior

Chinese Algae Eaters are semi-aggressive fish. For the most part, they’ll just spend their time alone at the bottom of the tank. They’re not particularly showy or active and prefer to hide instead.

A Chinese Algae Eater on driftwood

They can show signs of aggression to other fish, so be careful when picking their tank mates (more on that in the next section). Chinese Algae Eaters tend to attack fish that are close in color and size.

Also, don’t make the mistake of thinking that you can pair these fish up. It’s very likely that they’ll attack each other.

You should also be careful about larger gentle fish. They have been known to latch onto flat-bodied fish and be a nuisance. Some common targets for this behavior are discus and angelfish.

This behavior isn’t them being aggressive (or weird). In fact, they do this to eat the slime coat of the other fish. Unfortunately, it can injure the other fish and lead to parasitic infections.

Tank Mates

When picking Chinese Algae Eater Tank Mates you need to exercise a little bit of caution.

The first rule to follow is to avoid overcrowding the tank. These fish need plenty of space to keep aggressive behaviors at bay.

With that said, some owners have been able to pull off pairing them with peaceful fish that occupy the upper portions of the tank. As long as the other fish stay out of the way, it’s possible to make this work.

Here are some possible tank mates for Chinese Algae Eater:

Author Note: Some owners think it would be interesting to pair them with other algae-eaters like the Amano shrimp for the sake of complete tank cleanliness. However, due to the aggressive nature of Chinese Algae Eaters this isn’t a good idea.

Breeding

If you’re thinking about breeding Chinese Algae Eaters, be prepared for some trial and error. There are no established breeding methods. Those that have successfully bred these fish often do so by accident.

The biggest challenge is keeping a pair together. Not only are they prone to aggression, but there are virtually no physical differences between males and females. This makes it difficult to sex the fish for breeding.

If you are lucky enough to have a pair, you can try to trigger the breeding process by raising the temperature. This is a common tactic used for many fish species. While it’s not concrete, some aquarists have seen success by raising the temperature to 80 degrees over several days.

You may also want to try feeding your fish a nutrient-rich diet of live or frozen food.            

Making The Decision

Now that you know all about the Chinese Algae Eater it’s time to decide if they’re a good fit for you.

Due to their potential for aggressive behavior and limited tank mate options, a lot of aquarists pass. There are lower-maintenance algae eaters you can get after all!

However, we know a decent number of people who own these fish and absolutely love it. It’s an against the grain choice that can be very rewarding if you’re a fan of the species.

If you have any questions or suggestions on how we can improve this guide feel free to send them our way. We look forward to hearing from you!

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