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

Otocinclus Catfish is one of the best fish that are kept in fish keeping hobby as tank’s cleaning crew. However, most don’t know how many them to keep. So in today’s article, I am going to guide you on how many Otocinclus Catfish to keep in a 10-Gallon aquarium.

The general rule of thumb, 1 inch of fish requires one-gallon swimming space. So, if your tank is a species tank, you can keep about 4-6 Otocinclus Catfish in a 10-Gallon fish tank. Though, this number is affected by various other factors such as the size of the fish, are they kept with other tank mates, and so on. 

First of all, let’s start with the basic introduction of the fish. Otocinclus is the genus of the smallest catfish and belongs to the Lorincadae family. These fish are also known as Dwarf Suckers or Otos. The origin of the Otos is South America (mainly the rivers of Venezuela and North Argentina). Otos have different variations according to their color, size, and pattern. So, about 19 types of Otocinclus Catfish exist to date.

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Otocinclus catfish are tropical fish, which are suitable for aquariums. The average lifespan of this fish is 3-5 years. You should keep the Otos healthy and comfortable so that they live longer. If the Otos don’t feel secure and safe, they will die at an immature age.

How Many Otocinclus Catfish In 10-Gallon Tank?

If you are a bit aware of the Otocinclus fish, then you must surely know that these are shoaling fish. Otos loves to live in schools. These fish are small and peaceful, but it does not mean that you should overstock the fish. So, let’s get to the main question right away, i.e., How many Otocinclus Catfish can be kept in 10 gallons of water?

A small group of 4-6 Otocinclus Catfish is the best suitable option for 10 gallons of water. The Otocinclus Tapirape (smallest species) grow up to an inch only. On the other hand, The Otocinclus Flexilis(largest species) grows up to 2.2 inches long.

Up until now, you know how long does Otocinclus grow. So, you may decide about how many Otocinclus do you want to keep together. I’ve also seen some people keeping up to 10 of these fish in a tank. I’ll say that you must be careful because the Otos needs adequate space to swim around freely. The main thing that you need to focus on is that the Otos should feel comfortable.

The Behavior of The Otocinclus Catfish

Now, you know the adequate number of Otocinclus that are suitable to be kept in 10 gallons of water is 4-6 Otos. So, you must also know that these fish are the best algae eaters. It means these fish can clear all the excess algae in your aquarium. This unique factor is enough for you to pet the Otos. Not only about the removal of the algae, but Otos have a beautiful body pattern as well. The fish have a black-peppered body having tank-like shades. So, Otocinclus will also add glory to your aquarium.

Cost of the Otos

Buying Otos is not too expensive as well. You can get an Oto for about $3-$5. One important thing that you need to know is the more you buy the Otos, the less you need to pay.

If you buy 3-5: $3.89
Similarly, If you buy 6-11: $3.79
Lastly, if you buy 12 or more: $3.69

Isn’t it amazing?

I’m sure you are now wondering about the appropriate tank conditions for the number of Otocinclus catfish to be kept in 10 gallons of water. So, what are we waiting for?

What Size Tank Does Otocinclus Catfish Need?

Otos are community fish, so you must not keep these fish alone. It might cause psychological stress to your fish. This fish loves to stay in schools, and seeing them swim together will make you happier. The size tank for the Otocinclus depends upon the number of fish that you desire to keep together.

Related article: Aquarium Size and Weights

If you desire to keep six or more Otos together, it requires a tank with at least 10 gallons of water. But, if you keep 10-15 Otos together, it will require 20 gallons of water. When you add one more Otocinclus to your tank, remember to add a couple of gallons of water as well. It is because Otos are fast swimmers. These catfish needs adequate space to swim freely without any disturbance.

How Many Otocinclus Catfish Per Gallon?

Researchers have found that one inch of fish requires one gallon of water. Here, I will try to make it clearer to you. Let’s do a rough calculation. You already know that the Otocinclus catfish grow up to a maximum of 2.2 inches. Furthermore, let’s assume that the Otocinclus is of 1 inch, so you can only keep one Otocinclus in 1-gallon of water. It means that you must not let the fish grow up to its maximum size, and shift it to a bigger tank when it starts growing.

Let me be clear on one thing. You will not find a 1-gallon tank in the market. It is just an example to help you understand the rough estimation of the quantity of water that 1 Otocinclus needs. It will make it easier for you to calculate how many Otos do you want to keep together.

Tank Conditions For The Otocinclus Catfish In 10-Gallon Tank

Otocinclus are small and active fish species. These fish are shoaling fish. It means that the Otos love to stay in groups and not alone. You must keep a minimum of 10 gallons of water to your 4-6 Otos to live comfortably.

Otos are the bottom-dwelling fish, so it’s best if you set up the lower levels. Keep the sufficient plantations (Staurogyne repens), Substrates (artificial caves, rocks, artificial leaves, etc.), sandy bottom, and lighting. Having these will make the Otos happier and will prove to be the best pet fish. It is not hard to pet Otocinclus fish even if you are a beginner.

Related article: Easiest fish to breed

More About The Tank requirements In 10-Gallon Tank

Another main important factor is that your fish will entertain you with lots of activities and personalities. All you need to do is to make the Otos comfortable in the aquarium. I have seen an Otocinclus hang on the aquarium glass, and the suckermouth full in action. Trust me, it is an amazing sight to watch, and you will surely love it. Some of the Industrial Otos will continue to suck the rocks, or leaves, or anything with algae with it.

These fish are hard to catch even from a fishnet, due to their tendency of fast swimming. So, set up a tank that is deep and wide enough for the fish to be fully comfortable.

Remember not to be careless about providing overall care to your fish, as it might be fatal. Don’t be surprised if you lose your fish in a month or so.

Water Parameters

Maintaining an appropriate water parameter is an essential factor for every fish. Even though Otos are the best algae eaters, it does not mean that you should not leave the tank full of dirt and contaminated water.

Related article: How to clean a dirty aquarium?

The water must be clean with balanced levels of Nitrate and Ammonia at 0ppm. It is best if you change the water every one to two weeks.

On the other hand, the water temperature should be between 72-79°C. PH levels should be between 6.8-7.5, i.e., almost close to neutral.

Also, remember that Otos prefer soft water, not more than 15 DH.

Related article: How to maintain the hardness of aquarium water

Maintain The 10-Gallon Tank For Otocinclus Catfish

Like I mentioned earlier, Otocinclus are the best algae eaters. Algae are the natural food of these fish. So, you don’t even need to worry much. However, don’t forget to clean your tank once a week. Don’t leave excess dirt leftover in the tank. It will cause your Otos to stress out and get sick. Don’t forget that a proper filtration in the tank is an important factor.

Unlike other fish types, Otos are easy to take care of. It means you don’t need to spend much of your time and money on this fish. You don’t need expensive equipment for your aquarium as well.

Even though Otos can directly breathe in the oxygen from the air, you can still add a standard oxidation system to balance the oxygen in the aquarium. Sometimes, your fish may rise to the surface for air because of the lack of oxygen in the tank. So, be careful with these little things as well.

Balanced Diet Of The Otocinclus Catfish In 10-Gallon Tank

You might be surprised to know that Otos are herbivores. Yes, I’ve already told you that these are the best algae eaters. Now, herbivores? But yes, you read it right.

These fish usually eat algae as it is the natural food of the fish. You can give them other food as well.

Related article: How to feed an aquarium fish?

You can either buy some fish food from the stores near you or buy algae wafers. But if you don’t, then take the simple food items from your kitchen. Otos love to eat green vegetables such as Lettuce, Spinach, Zucchini, etc. Homemade fish food is also the best option for your Otos.

Related article: Can fish eat human food?

Just like any other fish types, you must not overfeed your Otos as well. Just feed enough food to keep them engaged for a few minutes. It is because overeating might cause difficult health problems to the Otos. Be careful because the excess food you provide to your Otos will be harmful. The uneaten food will decay in the tank, leading the tank to be dirty.

Related article: Why is my fish obese?

Diseases of the Otocinclus Catfish Due To Overcrowding

Otocinclus catfish don’t catch any diseases, unlike other fish. So, this is also another plus point about why to pet the Otos. But that doesn’t necessarily mean that they don’t get sick at all. Overcrowding of the fish tanks can cause the fish to get sick.

These fish might suffer from some parasitic and fungal infections like Common Ich, which are common among freshwater fish. An unhealthy tank and unsuitable water parameters will stress out the Otos. It might lead the fish to death as well. So, keep the environment clean and healthy.

Other Health Issues

Sometimes, a new environment with a clean environment and suitable water conditions might also be the reason for the Otocinclus catfish to stress out. Furthermore, when you set up a new tank, don’t forget to leave some algae behind. It is because algae are the natural food of the Otos. Any discomfort inside the tank may eventually lead your fish to stress out more.

You can find out that your Oto is unwell just by watching its activities and body. Some of the signs are loss of appetite, weight loss, inactivity, dullness, changes in the color of skin, the formation of spots, and an increase in respiration. You must be very careful with the signs.

Tankmates For Your Otocinclus Catfish In 10-Gallon Tank

Otocinclus fish are small sensitive beings and get scared very easily. These fish can easily be prey to the larger fish. So, avoid larger and aggressive fish (e.g., Cichlids, Oscar,etc.) to be their tank partner. It is because those will easily gobble the Otos in one go.

Related article: Red Devil Cichlid Care

As crucial beings, Otos will only prefer other peaceful beings as their tank partner. Guess what? You can still select a wider range of other fish species for your Otos. Some of the best tank mates are Angelfish, Cherry Barns, Corydoras Catfish, Danios, Dwarf Gourami, Guppies, Mollies, Tetras, Zebra Loaches, Harlequin Rasbora, etc.

Not only that, invertebrates like Snails and Shrimp also make a great tank partner to the Otos. You know why? It is because of the difference in their appearance and behavior. Even though the invertebrates and Otos are different from one another, these are compatible.

Related article: Why is calcium important for shrimps?

Adding More Fish To The Tank

You might also be wondering whether you could keep Otos only in your tank. Yes, you can. But, remember that only 4-6 Otos should be kept in 10 gallons of water. If you want to add some more fish in your tank, then increase the quantity of the water.

Breeding Your Otocinclus Catfish

One of the negative sides of the Otos is that these fish are hard to breed. As I mentioned earlier, these are fast swimmers. It’s hard to catch them even from a fishnet. However, don’t be hopeless, because it isn’t impossible as well.

A Separate Tank

You need to have a separate clean and healthy tank, with all the conditions fulfilled to make your fish comfortable. Check on the water conditions and the behavior of your fish. Increase the water temperature for up to 79°F, not more than that. That level of temperature will help a little for the mating to occur naturally. Also, don’t forget to feed the pair with a balanced diet. The breeding pair should not be hungry.

Like any other fish species, males are the ones who will woo the females for the mating. Here, the male Oto does the same. He chases the female around the tank. Once she agrees, both of them will hang opposite to one another and start mating.

One difference between Otos and other fish species is that Oto females are not egg scatters. Eggs are laid carefully on the soft surface of the tank, and the male will fertilize them later on.

Fry Separation

The fry comes out in a few days. As natural algae eaters, the fry will consume the bacteria and algae in the tank. Fry grows very fast. Then, it will take a few more days for them to start consuming what adult Otos consume.

Separate the fish when they are fully grown up. You must not forget to give the Otos the adequate space they require.

Related article: How to set up a fry tank?

Conclusion- Otocinclus Catfish in 10-Gallon Tank

I’m sure you know a little bit about the Otocinclus until now. You know how many of the Otocinclus Catfish can be kept in 10 gallons of water. You must be careful to maintain the dietary balance, water parameters, and tank conditions of your Otos.

Just like you need proper care in your day to day living, the same thing goes with your fish. Otos are sensitive to even slight changes in the environment. The Otos will find it hard to adapt for a longer period in such an environment, leading them to stress. It will lead to cause severe health problems for your fish. So, pay extra attention to keep your Otos fully comfortable.

Is Otocinclus Catfish Worth It?

Not only are Otos easy to care for, but these fish are inexpensive as well. The Otos have unique features of their own, which will prove to be your best pet fish. You won’t regret buying this beautiful species. You must be careful about providing them with overall care and giving a homely environment. Don’t exceed the number of more than the required Otos in a 10 gallons tank. It might make the fish uncomfortable and stressful.

If you want to add some more fish, just add a couple of gallons more water to the tank.

So yes, petting the Otos is worth it. I’m sure you’ll understand it soon. Happy Fishkeeping!

Also Read: Ramshorn Snail Breeding

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