Pictus Catfish Size – How Big Do They Get?

Disclosure: I may earn a commission when you purchase through my affiliate links. As an Amazon Associate I earn from qualifying purchases. – read more

This widely popular catfish called the Pictus Catfish is widely popular among aquarists. In its adult years, pictus catfish reaches 3 to 5 inches in size. Its final size depends on many different factors and we are going to discuss them all in this article.

You will know exactly how environmental factors, tank mates, diet and genetics affect the growth of the Pictus Catfish. In the end, you will walk away with some important tips and fun facts about this interesting community species.

Common Reasons Why Pictus Catfish Stop Growing

It can seem weird for many fish keepers when their beloved fish suddenly stops growing. Several months can go by without the Pictus Catfish growing even a tiny bit. There may be a few reasons behind that and fortunately, most of them can be controlled.

The ones that can be controlled are all environmental, meaning that you can do something about them right away. Let’s see what you can do to ensure that your little pet keeps growing.

Aquarium Size

Placing your Pictus Catfish in a big enough aquarium is very important. The minimum size for even a single fish of this species is a 50-gallon tank. Many beginner fish keepers try to keep them in a 10-gallon tank only to realize that it makes the fish stressful and also prevents him from growing.

If you notice that your fish keeps head-butting the aquarium glass throughout the day, then there might be a serious problem. It means that the fish tank is too small and your fish is basically going crazy. The organs of the Pictus Catfish keep growing while he simply can’t grow in size because there is just not enough space in the tank.

If you don’t want your fish to live a miserable life and get sick, then by all means buy a bigger tank.

Water Parameters

Besides a good diet, what the Pictus Catfish needs the most is clean water. Consider that 25 to 35 percent of the water has to be changed biweekly. There are plenty of contaminants that can build up in the water and cause them to be sick. It can even hinder their growth since they will become unhealthy and stressed out.

It is best to keep the water clean and to keep all the parameters between the recommended values. The temperature should be somewhere between 75 to 81 degrees Fahrenheit and the acidity between 7.0 to 7.5 pH.

To keep water parameters in check, you should have a test kit on hand.

Tank Mates

Pictus Catfish should be kept together only with those species that are compatible with them. There are plenty of aggressive, overly active and even voracious fish out there. Make sure they are not going to get bullied, injured or potentially eaten. Also, avoid those fish that would steal their food all the time.

Keeping them with too many tank mates is can also be an issue. Living in an overcrowded aquarium can cause the same effects as keeping them in a really small one. It is best to gradually add tank mates and monitor their behavior every day. Stress and lack of food can both hinder the growth of your fish.

Food & Diet

No matter what kind of food you drop in the tank, your Pictus Catfish is probably going to eat it. In a big community tank with lots of tank mates, however, things are not always that easy. You can feed all of them about 3 times a day but some of your fish are going to eat faster than the other.

Besides, we are talking about a nocturnal species here. Therefore, they are not going to be as interested in eating during the day. You will see them scavenging during the night, looking for food. That is when you need to give them a few additional bits. Carnivore pellets, for example, are great for them in the night hours.

The point is that you need to ensure that your Pictus Catfish gets enough food to eat and to take into account that they are nocturnal fish.


The Pictus Catfish is genetically predetermined to grow to a size of approximately 5 inches. This is true whether they live in their natural environment or in an aquarium. Since this is the case, placing them in an aquarium significantly smaller than 50 gallons is basically torture for them.

Although you won’t see noticeable growth on the outside, their organs will keep growing in the inside. This causes them great stress and suffering on the long run. It will cause great stress which will result in unusual behaviors such as constantly running into the aquarium glass.

How Long Does It Take for a Pictus Catfish to Grow?

It takes 8 to 12 months for the Pictus Catfish fry to become a full-grown adult. All the things we talked about above can hinder their growth. If you notice any unusual behavior or hindrance in their growth, then you need to keep your eyes open.

Feed them with a healthy diet and make sure they are held in the right conditions and with the right tank mates.

Can Pictus Catfish Grow Bigger in Large Tank?

They can’t grow bigger than 5 inches, yet they can definitely stop growing at a certain point in time. Since this can cause a lot of problems in the long run, it is definitely something you should fix immediately. First off, you need to put them in a 50-55 gallon tank.

This is the first step to ensure optimal growth for the Pictus Catfish.


We can conclude that ensuring that your Pictus Catfish reaches its full size is not always a simple task. This is a common issue among beginner fish keepers who don’t understand how things work in the world of these little pets.

Hopefully, this article made you understand everything that can contribute to, or hinder the growth of your Pictus Catfish. In the end, all you need to do is to spend a little time on research and your fish will be fine on the long run.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
Leave a Comment

Your email address will not be published. Required fields are marked *