How Many Zebra Danios In A 5 Gallon Tank?

Zebra danios are the perfect freshwater aquarium fish for first-time fish owners. Even if you’re an expert, they brighten up any tank instantly. If you’ve never had an aquarium, you may need to know how many zebra danios you can keep in a 5-gallon tank.

You can keep a maximum of seven zebra danios in a 5-gallon tank. Holding more than seven will increase the risk of stress, and the mortality rate will rise. Zebra danios school together to feel safe, so keeping less than four in a 5-gallon tank is not advisable.

Because they are so small, it’s easy to assume they don’t need that much space, but that’s not the case. Even in the water, fish like zebra danios need room to grow, socialize and forage. If they are overwhelmed, they become sad and stressed.

How Many Zebra Danios Can Fit In A 5 Gallon Tank?

A 5-gallon tank will be a good size for five to seven danios. However, you should consider several things regarding how many danios you should keep in a 5-gallon fish tank.

First, a good thing to remember is danios prefer to be in a larger group rather than alone.

A 20-gallon fish tank is perfect for ten zebra danios. However, keeping more than eight zebra danios in a 5-gallon tank can cause aggression and stress.

Keeping their water temperature around 70 degrees Fahrenheit is recommended to ensure they stay healthy and happy.

Instead of six to seven danios, you can keep four to five and keep other fish in the tank with them. There are a few friendly fish you can keep with your danios, such as:

  • Rainbow fish
  • Yoyo Loaches
  • Honey Gourami
  • Barbs
  • Clown Fish
  • Emerald Pufferfish
  • Swordtails
  • Celestial Pearl Danio
  • Redtail Shark
  • Pleco Catfish
  • Corydoras Catfish
  • Most Loaches

Zebra Danio Side View

What Size Tank Is Best For Zebra Danios?

You should keep five zebra danios in a 10-gallon tank to avoid overcrowding your danios tank.

If you overcrowd the tank, it will affect their growth and result in health issues and stress. They can also become aggressive and end up killing each other.

If you don’t just want danios, then you can add other fish too. But danios prefer to be in a larger group since they are schooling fish. So keeping them in a group of at least five for healthy development.

When looking for the best size tank for your zebra danio, use the one-inch-one-gallon rule since it will help determine how much space they need. A zebra danio is about one or two inches, so a two-inch one will require two gallons of water.

Since zebra danios school, they have to be placed in a group of five. You can put them in a ten-gallon tank, depending on their length.

What Happens If You Overcrowd Your Danios In A 5-Gallon Tank?

Overcrowding your danios can quickly happen if you don’t follow the one-inch-one-gallon rule. Here are several things that could occur if you overcrowd your zebra danios:

  1. Crowding your zebra danios in a tank can spike the tank’s ammonia levels and cause your fish to suffer from ammonia poisoning.
  2. When they are overcrowded, they get stressed very quickly.
  3. Having your danios in a crowded tank can also lead to aggression.
  4. Loss of appetite can happen when the tank is overcrowded since the water quality drops.
  5. The growth of your zebra danios will be affected since they will have no room to swim due to an overcrowded tank.

Zebra danios do great with other fish that are calm and non-aggressive. So you can place your danios with other fish with the same temperament.

Adding other fish to the five-gallon tank is not recommended since it might cause the tank to be overcrowded.

If you want to place zebra danios with other fish, try getting a larger tank or putting only five danios and a few other small fish.

What To Put In My Zebra Danios Tank?

When decorating your fish tank to make your danios feel more at home, you should look at where and what plants they live around.

You can also add other accessories that will make the tank look pretty. Ensure you only put safe accessories for your fish and won’t harm them.

You can add many things to a tank depending on the space of the tank. Here are a few ideas on what you can add to your zebra danios tank:


  • Money plant: These plants can be placed at the top of the fish tank and have roots that grow in the water. With enough light, the plant with thrive and grow well. The money plant also absorbs nitrates and uses them to develop.
  • Anacharis: This plant is a low-maintenance plant making it easy to take care of. The anacharis can adapt to many different water conditions, but they live best in water that is 22-25 degree Celsius.

It needs moderate light to grow. It can be left to float on the surface or be planted.

  • Java moss: This is a prevalent aquarium plant and is very easy to maintain. It can be in temperatures around 22-32 degrees Celsius and is known to float. Attaching it to something is recommended so it won’t float everywhere.


  • Driftwood: Putting natural driftwood in a fish tank is very popular and can create a natural look. It’s a perfect place for fish to hide if they are shy. It’s a very safe accessory and can be bought at many stores or found in streams.
  • Stones and rocks: There are hundreds of different rocks that you can find or buy. If you find rocks in streams or ponds, sanitize and clean them before putting them into your aquarium. Rocks can comfort fish by mimicking their natural habitat.
  • Caves: Putting a rock cave in your tank is perfect for fish to hide if they feel shy or threatened. And it is just a cute addition to the tank.


Keeping your danios in a five-gallon tank is easy and possible, but they will eventually need a larger tank.

If you have the space for a larger aquarium, you can easily migrate your zebra danios once they mature.