Fish Guide

Can An Otocinclus Catfish Live Alone? Can I Just Keep One?

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This article is especially for all of you fish lovers out there. I’ll be talking about the Otocinclus Catfish today. Furthermore, I’ll try my best to answer the query of, “Can an Otocinclus Catfish live alone?”.

For starters, Otocinclus Catfish cannot live alone. Since Otocinclus Catfish is community fish, it lives in peace with other tankmates like Ramshorn Snails, Shrimps, etc.

I have seen people having so many queries about this beautiful catfish. The most asked one is, “Can an Otocinclus live alone?” I also have been curious about the same question, and so I conducted research. I will try to make it very clear to you in this article. Let’s begin now, shall we?

Can An Otocinclus Catfish Live Alone?

Otocinclus are schooling fish and love to stay in groups. So, it is clear that an Otocinclus can’t live alone. However, you should only separate your fish from the community tank if it gets sick. Don’t leave your fish alone for a long time, though.

As a community fish, Otos will not adjust to staying alone and will suffer from psychological stress. Stressing out more will even lead to further health complications and even untimely death of the fish. So, it is right when they say, “Prevention is better than cure.” Now, you know what to do, don’t you?

To know about more diseases in fish, check out our articles about Hole In The Head Disease: Cause, Treatment and Prevention and Treatment and Home Remedy for Fin Rot Disease in Aquarium Fish

Hence, keep your Otos in a group so that these fish live healthy and happy. This article will help you find more about these beautiful catfish.

The Behavior Of Otocinclus Catfish- Can An Otocinclus Catfish Live Alone?

Otocinclus Catfish cannot live alone, and you will often see them grazing in groups. Otos swim together, showing their suckermouth full in action. So, it is quite fun to see these catfish sucking the algae inside the tank.

As mentioned earlier, Otos are quite small and peaceful beings with friendly nature. These fish are vulnerable beings and fear being prey to the larger fish. So, you must be careful while choosing their tankmates. We will come back to the tank mates part later on. For now, let’s get clear about the behavior of the Otocinclus catfish.

Relative Article: Health benefits of having an aquarium fish

Otos are active and fast swimmers, so you can’t catch them easily, even from a fishnet. You will usually see the fish floating at the middle and lower levels of the tank. These fish are mainly famous as “the best algae eaters” of the fish keeping world.

Furthermore, these catfish are sensitive beings just like you, so make sure you do not make them stressed out. Otos tend to hide more when they are either stressed out or sick. That is the reason why you need to take proper care of these beautiful catfish.

Size Of The Otocinclus Catfish

The average size of the Otocinclus catfish ranges from 0.6 inches to 1.7 inches (16.5mm to 43.8 mm), excluding the tails. Males are comparatively smaller than the females. Males have a flat body, while females are broader, especially in the time of breeding.

Price Per Otocinclus Catfish

Otos aren’t expensive to buy, it will cost up to $2 to $4. However, there is good news for you. The more you buy the Otos, the less you need to pay. It is because the Otos are wildly caught in groups by the fish keepers and simply sold in a group. How cool is that? But beware! You need to be careful and alert enough to buy healthy Otos.

Tank Conditions For The Otocinclus Catfishes

You already know that Otocinclus Catfish are shoaling fish and can’t live alone. It will lead to further health complications.

After that, the most important thing is to set up a perfect tank for the fish.

Any fish species are easily prone to get stressed out, which might even lead them to get sick. So, that means you need to take proper care of your fish. It is more vital, especially when you keep the fish in a small aquarium.

How Many Otocinclus Catfish To Keep?

Since the Otocinclus are shoaling fish, the main query “Can an Otocinclus live alone?” is already solved. Isn’t it? You must keep the Otos together in a minimum of 3. However, it is best if you keep 5 to 6 of the Otos together.

But do you know the ideal tank size for your fish? The size of the tank is normally 10 gallons, while you can also go up to 20 gallons. Since Otocinclus are small in size, any size bigger will not look good unless you want to pair it with other species.

I suggest you Tetra Aquarium 20 Gallon Fish Tank Kit, Includes LED Lighting and Decor for the 20 gallons aquarium as it is the best for the affordable price. You can also understand better through our article on How To Setup A 20-Gallon Fish Tank: Livestock and Equipment List.

How Many Otos Can You Keep Per Gallon Of Water?

As many researchers have found that one inch of fish requires an average of one-gallon water, you can only keep one Otocinclus in one-gallon water.

I’ll try to make it clearer to you by doing a rough calculation here. Let us analyze when the Oto grows up to 1.5 inches. That means you need to add roughly 2 gallons of water.

Related Article: How many Otocinclus Catfish To Keep In A 10-Gallon Tank?

What Is The Ideal Tank Size For The Otocinclus Catfish?

You already know that the 5 to 6 Otocinclus is the ideal number of fish to be kept together by the rough calculation we have done above. So, a tank consisting of 10 gallons of water is the best ideal size.

Adding More Otocinclus In Your Tank- What To Do?

If you are wondering about adding more Otocinclus to your tank, then you must surely add more gallons of water. When you have 4 to 6 Otos, keep 10-gallons of water. When you keep 6 to 10 Otos, keep 15-gallons of water. I guess you understood what I’m trying to say. Remember, each additional fish requires a couple of gallons of water.

Maintain The Water Parameters

Don’t forget that Otocinclus Catfish are also sensitive beings just like you. Small carelessness and mistake regarding the water, and you will pay the price of your fish’s death. So, you must maintain the right water parameters for your fish.

Make sure you keep the nitrate and ammonia levels all balanced to zero as well. You should not make your Otos stressed out because stressing out will make them sick and can even lead them to an untimely death. I keep on repeating this thing because you should never be careless when it comes to your fish.

Related article: How to maintain the hardness of the water in the aquarium?

Now, let’s find out the exact water parameters required for your Otos.


One of the most important things about maintaining the water parameters is the water temperature. The ideal water temperature for the Otos is between 79 to 82 degrees Fahrenheit (22 to 28 degrees Celcius.)

Ph Level

Otocinclus catfish prefer slightly acidic water with the PH level ranging from 6 to 7.5. Remember not to exceed or decrease the level. You can learn a lot from ‘How to Increase pH Level in a Freshwater Tank?’

Proper Filtration System

Otocinclus Catfish is famous as the best algae eaters in the aquarium fishing world. Even though these fish have the unique capability to clear the excessive algae from the tank, you must have a proper filtration system.

It is because you need to keep the water clean and healthy. It is best if you change at least 20 to 30% of the water once a week. You can easily buy the filtration equipment online or through the stores near you. HIKARI Bacto-Surge Foam Filter Mini could work best for the Otocinclus tank.

You can get a better idea of Is Too Much Water Change Harmful For Your Fish: How To Do It Safely from here.

You can easily buy the water heater, temperature checker, and filtration equipment online or through the stores near you. Always remember to maintain the water parameters to keep the Otos healthy and safe.

For a small fish tank, hygger 50W Mini Submersible Digital Display Aquarium Heater would be best. It is a Compact and Fast Heating Thermostat, with External Controller and Built-in Thermometer.

Suitable Decoration

Otocinclus Catfish prefer a tank that will somehow match their natural habitat. So, you need to keep enough plantations and enough hiding places for your fish. Keeping those things will make the Otos more comfortable having a homely environment.

Staurogyne repens is the best plantation for the Otocinclus Catfish because your Otos will have enough places to hide. Not only that, but it also is the best plant for algae formation.

Don’t forget to add artificial plants and rock caves as well. It will enable the Otos to hide whenever they get stressed or scared. Not only that, but plenty of hideous places will also help the Otos to rest peacefully.

I have written in detail about the beginner’s guide on decorating the fish tank.

Lighting System

Another important thing that you must not forget is to keep a standard lighting system in your tank. It is necessary because Otos don’t prefer a darker environment.

NICREW ClassicLED Aquarium Light, Fish Tank Light with Extendable Brackets, 48-Inch, 32 Watts would be a great choice in such a case as you can adjust the lights as per need.

Otocinclus Catfish Diet

If you don’t know, Otocinclus Catfish are herbivores. Even though these catfish are herbivores, you will mostly find them eating or sucking the algae in the plants.

Furthermore, various fish foods are suitable for your Otocinclus catfish.
You can buy the Alage wafers and other frozen food items from the department stores or the fish stores near you.

Learn from Fish Food 101: A Beginner’s Guide On How To Feed Aquarium Fish.

However, if you don’t intend to feed your fish with the packet food items, then you can select the items from your kitchen. Choose green vegetables such as Lettuce, Spinach, Zucchini, etc.

You might also like ‘Can aquarium fish eat human food?’.

No Overfeeding

Just like you feel uncomfortable after you overeat, the same condition goes for your fish as well. Although the Otos will eat as much as you provide, remember to feed enough quantity, neither more nor less. It is because overeating will not only make the fish fat, but it will lead to other health complications as well.

Tankmates For The Otocinclus Catfish

Otocinclus catfish have a peaceful, non-aggressive, and friendly nature. So, you might have already guessed that these catfish will not adjust well with larger aggressive fish species.

Avoid larger fish like Cichlids, Aquarium Crayfish, Goldfish, Jack Dempsey, Oscars, Striped Convicts, etc., because small fish will fall on to the prey of the larger ones. Not only that, but Otocinclus are small and get scared very easily. As expected, it will lead to the downfall of the health of Otos.

Related article: Red Devil Cichlid Care Guide

The best tankmates for the Otocinclus Catfish are Angelfish, Dwarf Gouramis, Mollies, Tetras, Guppies, Corydoras Catfish, Cherry Barbs, Danios, Zebra Loaches, Harlequin Rasbora, Boraras, etc.

Also read: Longfin Leopard Danios: Everything You Need To Know

Besides, some invertebrates such as Snails and Shrimps are best with the Otos. Nerite, Ramshorn, Mystery, Gold Inca, Ivory, Malaysian Trumpet, Rabbit, Japanese Trapdoor, and Pond, etc. are the types of Snails. On the other hand, Bamboo, Vampire, Red Cherry, Ghost, Amano, and Whisker are the types of Shrimp.

Breeding Process Of The Otocinclus Catfish

Despite having all the good qualities, Otocinclus are hard to breed, especially if you are a beginner. I didn’t intend to demotivate you, though.

Related article: Easiest fish to breed for beginners

As you already know, these catfish are fast swimmers, and you can’t catch them easily, even from a fishnet.

Once you get lucky and finally catch the pair, the second important thing that you need to do is to make the breeding tank cozy and comfortable. Make sure you keep the tank temperature moderate enough for the pair to adjust well. Keep the water temperature up to 79 degrees Fahrenheit. Slightly warm water temperature will encourage safe and fast breeding.

The Behavior Of The Otocinclus Pair

You will often see the males chasing the females around the tank.

Males will fertilize the eggs while mating, after which the females will lay eggs in the bunches of plants, or the lower surface of the tank.

The fry comes out and starts swimming after a few days. Those days are the most crucial part because slight carelessness in the overall care will kill them. Make sure to keep the fry safe and comfortable by providing enough diet and the right water parameters.

Related Article: How to set up a fry tank?

Interesting Facts About Otocinclus Catfish

Otocinclus catfish is one of the famous aquarium fish in the fishkeeping world. It belongs to the Loricadae family. Talking about the origin of the Otos, these fish belong to the South American territories (rivers from North Argentina and Venezuela). Here are some facts about Otocinclus as a bonus:

  • These are tropical freshwater fish.
  • There are about 19 species of Otocinclus catfish available to date due to the selective breeding process happening every year.
  • Otocinclus are also called “Otos” or “Dwarf Suckers” as well.
  • Otocinclus is the combination of Greek and Latin words, ie. Oto (Ear), and Cinclus (Latticework), respectively.
  • These catfish will add vibrancy to your aquarium with the variations of the colors and patterns.
  • Not only that, but Otos also have a unique capability of clearing up the excessive algae in your aquarium.
  • Otos are mainly famous as the community tank fish because these fish have peaceful temperaments and are not hard to pet.

Last Words

I’m sure you understood the main answer to the question, “Can an Otocinclus catfish live alone?” No, because these are shoaling fish and loves to stay in groups. So, be careful if you are thinking about petting these beautiful catfish.

However, let make it clear to you that petting the Otocinclus Catfish is worth your time and money. So, why not?

Happy Fishkeeping!

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