Do Betta Fish Grow In Bigger Tanks?

You might’ve heard that goldfish will stay small when placed in a small bowl. They will grow bigger when placed in a large tank. Do bettas work the same way?

So, do betta fish grow in bigger tanks versus smaller ones? Does the size of the tank matter? How big will they get? Keep reading to find out.

Do Betta Fish Grow In Bigger Tanks?

The answer to this question depends on what exactly you’re asking. If you’re simply asking if betta fish will grow in large tanks, then the answer is “yes”.

But, if you’re asking if a betta will grow bigger when it’s kept in a large tank versus a smaller one, then the answer is “no”. Bettas are not a type of fish that keeps growing and growing throughout their lifetime. They stay quite small regardless of what size tank you house them in.

So, if the tank size doesn’t influence the size of your betta, then what does?

How Big Do Betta Fish Get?

The average adult betta fish will only be about 2.25 in (5.7cm) in length. Some have grown up to 3 in (7.6 cm) in length, but this isn’t very common.

What Influences Your Betta’s Growth

We’ve already established that a smaller tank will not grow a smaller betta and vice versa. Yet, many people notice that their bettas stay on the smaller side when kept in a smaller tank. Why is this?

Water Quality

The bottom line is that a small tank is not going to stunt your betta’s growth based on its size alone. Unlike goldfish, bettas won’t become stunted due to the size of their tank.

What CAN stunt their growth is a lack of water quality which is often linked to a smaller tank.

The problem with bettas is that they’re seen as easy beginner fish. People buy them on a whim and house them in a small bowl or tank without any filtration or heater. While the size of the tank itself won’t stunt your betta, these other things will.

Despite what most people believe, larger tanks are more beginner-friendly than small ones. This is because the water parameters are going to remain more stable in a larger aquarium. You need to watch water parameters more closely for small aquariums. They’re more liable to fluctuate.

Now, imagine a betta living in a 1-gallon bowl with no filtration. The water is stagnant, and the fish is swimming around in its own waste and leftover food.

That bowl is going to become dirty very quickly causing an ammonia, nitrite, or nitrate spike. If the bowl has no filter, this problem is only going to become worse.

Poor water quality is very dangerous for fish, and it CAN cause stunting of your betta.

Likewise, many people who house their bettas in a bowl or small tank don’t buy a heater. Bettas are tropical fish and need warm water temperatures.

If the tank is not warm enough, their metabolism will slow down. It will also compromise their immune system. So, they will be more susceptible to illness and infection.

What Should You Provide Your Betta?

To keep your betta happy and healthy, there are a few basic things you should provide it.

Here is the essential betta fish starter kit:

Food That Lacks Nutrition

Another reason your betta may become stunted is if you aren’t feeding it correctly. Bettas need high-quality, protein-packed foods to grow and be healthy. Foods with little nutritional value will stunt the growth of your betta.


If you keep your betta in a large tank, it will grow to the same size as it would in a smaller tank. That’s not to say that larger tanks aren’t any better for a betta than a small tank. Bettas love to swim and will appreciate all the extra space they can get.

So, by all means, get as large of a tank for your betta as you like. Just know that it won’t result in a large, oversized betta.

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