How Big Can Betta Fish Get? Here You Go!

It’s no breaking news the fact that betta fish is an amazing water pet to have. They are neat and very interactive. The uniqueness lies in the brightness of their skin, aggressiveness and interactive personalities. in this long and detailed article, we will be dealing with some of the questions some betta owners seem to be asking; How big can a betta fish get? How do I make my betta grow bigger? What’s the recorded largest betta fish? How big can my female betta fish get? And, what are the common problems faced when using small tanks? These are some of the questions we will be dealing with today.

How Big Can My Betta Fish Get?

Do betta fish grow at all? Yes, they do. Asides the fact that it is a norm for every living organism at some point experience growth, Siamese fighting fish or betta fish as they are fondly called grows in synchronism with its age. simply put, betta fish grow as it gets older. Of course, this isn’t infinite as the growth will be halted at some point. Your betta fish is considered fully developed once it crosses the 7 months threshold. But, depending on the environment and how well they are taken care of, they can always grow larger.

Every betta fish purchased from the pet store are usually 6 months to a year old. Meaning, a betta fish got from the pet store is relatively a ‘fully developed’ one. Fully developed as in they may be close to their final developmental stage. That’s when they develop their beautiful fins. The age, fins and overall size of a betta fish may differ depending on the breeder or the breed, it could also be a combination of both. But the final developmental stage depends on your management skills.

Nowadays, you’ll find some pet stores selling young (baby) betta. These bettas range from 5 weeks to nine weeks. Obviously, unlike the usual betta fish purchased at pet stores, baby bettas will be a lot smaller in size and require premium – quality management skills. Advisably, if you aren’t experienced enough to deal with the care, excesses, and monitoring needed by these baby bettas, don’t bother getting one. Instead, get yourself the fully developed betta fish which is by far bigger and requires relatively less attention and care (the keyword here is relative, we all know that bettas generally require top-notch management skills).

How Big Can A Betta Fish Get?

The average length of a fully developed betta fish is 5.7 cm (2.25 inches), but this is just an average number. Normally, nurtured under the right condition, a betta fish can grow up to 7.6 cm (3 inches) in length. The growth tendency of your betta depends on his age and how well it’s been catered for.

Worthy of note is the fact that gender also defines the size of a betta fish. A male betta’s length is significantly different in comparison with the female counterpart. For instance, male betta fins are quite bigger, unlike the female bettas. But when they both get to the peak of their age; they tend to grow to the same size. What usually makes the male seem bigger is the size of their fins. Finally, male bettas tend to have a thicker body when compared with the female bettas.

3 Tips To Make Your Betta Grow Bigger

As a pet lover, it is usually a thing of joy when you see your pet grow bigger. Obviously, it is impossible to have your betta grow to the size of the tank. That’s not possible. If you wish to have your betta grow bigger, there are some certain things you need to do. For instance, the growth of betta could be tampered with if placed in habitat is not up to 5 gallons. If you want your betta to thrive, you need to place it in a tank that’s at least 5 gallons in volume.

Just as we’ve stated earlier, being a tough fish doesn’t mean they are not susceptible to different aquatic diseases. Limit the stress then you will aid its growth. Certain factors could contribute to its death and slow or stunted growth. Spot these factors and you would have added to the overall health of the fish.

Water Management

Next to the volume of the tank is the water itself. The water must remain clean at all times. You can do that with the right filter. Also, you should make sure that the overall temperature of the water is between 76 to 82 degrees Fahrenheit. An ideal tool to help maintain the temperature of the water is the thermostat heaters.

Water temperature and quality is an important aspect when dealing with betta fish. Generally, water quality is part of the things that defines the overall growth of a fish. Undigested food crumbs, uneaten feed pellets, feces, and urine will always pollute the water, but your ability to manage the quality, flow through and the filter will go a long way. Preferably, the filter pressure should below. A low-pressure filter will help keep pushing out the water toxins. Also, a low-pressure filter will ensure that the fins are not damaged.

What type of water do you use? Yes, that also matters. Avoid tap water as they are known to contain toxic chemicals. For instance, the chloramine and chlorine found in tap water are known to be toxic for a betta fish. These chemicals can also make your fish become lethargic. A better choice is bottled water. Bottled water is free of chloramine and chlorine, and some other toxic chemicals which are capable of harming your betta fish. Finally, one other type of water to avoid is the distilled form of water. Distilled water lacks the needed minerals which will ultimately aid the growth of your betta fish.

Speaking of water management, you should ensure that more than 25% of the water is changed once a week to prevent infections. Also, we add decorations in the tank to ensure that our bettas don’t get bored and sleep off all the time. But these plants should also be cleaned, likewise the gravels and every other thing you have in the tank. Ensure that these things are kept clean.

The Tank Size

Next to water management is the size of the tank. If you want your betta to remain small, then you can always go for anything between 2 – 2.5 gallons. But, to optimize the growth of your betta, your best bet is to make use of the 5-gallon tank. Meanwhile, 5 gallons is the minimum number, you can always go for something bigger. Advisedly, you should make sure that you create a conducive environment for your betta fish.

The Cons of having small tanks:

There are tons of cons that surround using small tanks for water pets generally. Firstly, fish shouldn’t be restricted, fish need exercise, so does bettas too. Therefore, the bigger the tank, the more space it has to exercise and swim around. All of these add to the overall wellness of the fish.

Small tanks get dirty very quickly. If you don’t want your betta to get ‘burned’ by his poop all the time, then you need to make sure that the tank is big enough for him. Most small tanks don’t have carbon filers installed in them. What happens when there are no carbon filters? The water gets polluted quickly. Then, you will have ammonia amongst other toxins to deal with.

Better dieting

Bettas grow more effectively off a diet high in protein. They are carnivores and solely depend on betta pellets rich in protein-coupled with brine shrimps or freeze-dried bloodworms. To replicate their natural habitat, you could also try out live foods, but be careful as some of these live foods carry different forms of diseases. It is important to note that bettas can’t (and don’t) feed off the roots of plants. The only role played by the plant is to provide a hiding spot and shade for the food. They are not meant to act as a substitute for the normal food required by bettas to grow healthily.

When you feed your betta more food than the fish can eat, it can be fatal for that fish. When feeding your betta fish, you’ve got to be patient. Excess feed in the water (especially when you are using a small tank for the fish) can increase the bacteria level in the water. It tends to leave bettas susceptible to infection and different forms of diseases. So, avoid excess feed and make sure it doesn’t exceed 2 to 3 minutes when feeding them. One other thing excess feed is known to cause is bloating. Just like we mentioned in our previous article, bloating is capable of killing your betta fish.

How Big Can Bettas Get In The Wild?

The size of bettas in the wild is not distantly different from what you have with the captured bettas. Averagely, bettas in the wild grow as long as 2.25 inches. The difference lies in a conducive environment. The susceptibility of bettas in the wild to pollution and danger tend to limit their growth.

Do Bettas Grow To The Size of Their Tank?

This is one question a lot of betta keepers tend to ask. Objectively speaking, it is possible to have betta grow to the size of his tank. Few pieces of evidence support that fact. Even though it’s a phenomenon, it does happen. The caveat is, this phenomenon does not happen always. Realistically speaking, it usually works in a predictable direction. In a situation where you have a betta in a small tank, at some point, the bettas growth will be stunted. This usually happens right before the fish gets to its full developmental stage.

Sometimes (if not most of the time), the genes of the fish might stop functioning, this automatically leads to a halted growth, especially when the fish grows to 2 inches in length. So, if in this case, the tank is a small one, then there is a high probability that the fish could grow bigger than the tank. Simply put, your betta tank should always be big.

How Big Can A Female Betta Get?

What’s the maximum length of a female betta fish? Like we stated earlier, the difference between male bettas and female bettas lie in the outward appearance of both. Generally speaking, female bettas look small in length compared to their male counterparts. Female bettas have smaller fins while make bettas have bigger fins. This difference creates an elusive image, making the male bettas to appear larger. But overall, the difference in size lies in the size of the fins and nothing else.


As we’ve pointed out, bettas aren’t big. Just some inches long. But you can always optimize their growth and get the best out of them. the biggest betta is recorded to have reached 3 inches in length. Generally, you can make your fish grow to that length. It takes experience, professionalism, patience, top-notch water management skills, and of course, quality time. if you try as much as you can to create a conducive environment for your betta, chances are, it may grow longer than you think. Remember:

Keep your betta in a big tank (minimum is 5 gallons)

Also, make sure that the water temperature stays between 72 degrees Fahrenheit to 80 degrees Fahrenheit. Ultimately, what this does is to make sure that your betta remains warm. When it comes to the growth of your betta, managing this well plays a huge role.

Try to change the water (at least half of it) regularly. You can replace the water with a preconditioned one.

On a final note, you need to understand that bettas also produce hormones that responsible for halting their growth.

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