How Much Water Does a Betta Fish Need?


Betta fish may be the most popular aquarium fish today, simply because of their beauty.

If you decide to get a betta fish, you will have to figure out how much water your betta fish needs. Don’t worry, there is a simple formula to follow…

The general rule of thumb for all aquarium fish, including betta fish, is one gallon of water per inch of fish. One betta fish will need a minimum of 3 gallons of water since betta fish grow 2-3 inches. Since you don’t know how big your betta fish is going to get, it is safer to go with the maximum size. In essence, you would need 3 gallons of water for each betta fish.

However, based on the reputation of the betta fish, a better question to ask would be…

How Much Water Does A Betta Fish Need To Be Happy?

If you go shopping for a betta fish at a pet store, you will probably find a lot of betta fish in tiny cups or bowls that are not remotely close to 3 gallons.

You may think this is because they are just being stored that way temporarily, but betta fish have a reputation of being able to survive in tiny spaces. So much so that you will even find betta fish living in wine glasses as decorations!

Betta fish come from shallow rice paddies, where the water goes through droughts or simply dries up into puddles.

Betta fish actually have a ‘labyrinth organ’ that allows them to go to the surface of the water and breathe oxygen when most of the oxygen is dissolved in these tiny puddles.

Betta fish have adapted to living in these tiny puddles and will even jump into another puddle to try to get to more water.

Because of these living conditions, betta fish are very hardy fish, which means they can live in some pretty harsh conditions. This also means that a lot of people think it is okay to keep betta fish in these tiny containers of water.

However, betta fish are much happier with more space to roam around and explore.

Betta fish are very intelligent and like to explore different plants and decorations to keep themselves entertained. It’s kind of hard to do in 3 gallons of water.

We recommend at least 5 gallons of water to start out and then 3 gallons at a minimum for the rest of the fish, or if you are going to have a community tank including other fish, you can follow the gallon per inch rule after the initial 5 gallons.

More Water = Easier To Clean

Betta fish are happier in clean water because they won’t get sick. It doesn’t matter how much water your betta fish has if they are sick they won’t be happy.

If your betta fish is stuck in a small bowl with no filter, then you will have to change the water every day to every other day to keep the ammonia, nitrite, and nitrate levels down.

If you have a bigger tank with at least 5 gallons of water, you will have room for more live plants that can help filter the water. You will also have room for a filtration system even in the tank, although we recommend a hang on the back filter or a canister filter to put under the tank.

The more water you have in your tank, the more room there is for bad bacteria to spread before the water becomes contaminated.

So, if you have more water than recommended it is a win-win because the water needs to be changed less and the betta fish has more room to run around – whoops – I mean swim around and play.

Don’t Make This Mistake

Another reason that we hit on above, with a minimum of five gallons for the first fish in your tank, is you need to account for the space that filters, heaters, plants, decorations, etc will take up in your tank.

If you simply start out with 3 gallons of water for a 3-inch fish and then add a bunch of decorations, plants, a heater, and maybe even an in-tank filtration system, you may only end up with 1.5-2 gallons of water space for your fish since these other objects are taking up space.

The More Water The Merrier

It never hurts to have more water than recommended when it comes to aquarium fish so it is better to err on the side of caution anyway.

Just give your fish more than the recommended amount of water and no worries!

Any fish in their right mind would love to have more space to explore and swim around. You can never have to much water so just give more than enough and you won’t have to worry about it.

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