Flame angelfish are active swimmers that grow up to 4 to 6 inches in length. So a minimum tank size for flame angelfish depends on numerous factors like the reef tank layout, number and size of other fish species, etc. However, keep one male and 2 to 6 female flame angels in a large 125-gallon tank.
Let’s understand the various factors that determine flame angelfish tank size in more detail.
5 Factors to Determine Flame Angelfish Tank Size
Flame angelfish are small fish. However, despite their small size, they’re active.
So choosing an appropriate tank size for them is tricky.
Besides, aquariums come in different shapes and sizes.
There are tanks that are as small as 10 gallons to as big as 200 gallons or even bigger.
However, marine aquariums have different requirements than freshwater aquariums.
Apart from the fish species, other things should also be factored in before determining the tank size.
Given below are some of the factors to consider when deciding on the right tank size for flame angelfish.
1. Number of Fish
The tank size is directly proportional to the number of fish you want to maintain in the aquarium.
Flame angelfish generally prefer to live in pairs or small groups, so they don’t enjoy being kept in isolation.
You can keep flame angels with other small tropical reef aquarium fish that are similar in size and temperament.
Make sure there is plenty of swimming space for all the fish in the aquarium.
2. Size of The Fish
Flame angelfish are small in size but require lots of swimming space.
A single flame angelfish requires at least a 30-gallon tank, but it’s best to provide more room to curb aggression.
Flame angelfish are peaceful fish species but become territorial and compete with other fish for food in certain situations.
So keeping them in a large tank is recommended.
3. Tank Layout
Flame angels like to spend most of their time close to the bottom of the tank, grazing on live rock.
Therefore, they should be housed in an environment similar to their natural habitat.
These fish are shy and prefer to hide.
Rocks of various shapes and sizes should be placed in an aquarium for the flame angels to hide or seek shelter.
Coral reefs can be added to their aquarium to create a natural environment.
So, besides the fish species, coral, live rocks, and an open swimming space should be considered before determining the tank size.
4. Tank Maintenance
Flame angels are relatively easy to care for, but if they don’t get enough attention, they might not be able to survive.
Regular aquarium maintenance is required for stable water conditions.
Larger tanks tend to be easier to maintain than smaller tanks.
As the size of the tank increases, it becomes easier to maintain stable water parameters.
Regular tank maintenance is time consuming and needs a lot of effort.
So investing in a large setup will help you save valuable time and effort.
5. Tankmates

Tankmates are another crucial factor to consider while determining the tank size for flame angelfish.
These fish are compatible with other peaceful fish found in community tanks.
You should take into account the space needed for the tankmates too.
The tank size needs to be large enough so that each fish has plenty of space to live comfortably.
Lack of space causes territorial disputes between tank inhabitants, resulting in aggression and stress.
Can Flame Angelfish Live in A Nano Reef Tank?
Flame angelfish can live in a nano reef tank as they’re small in size, reef safe, and well-suited for captive environments.
However, it’s not ideal to keep them in a nano reef tank.
Flame angels are active fish and like to swim around the tank.
So, a nano reef tank creates challenges for them since it’s typically 30 gallons or less in size.
Besides, a reef tank contains coral, invertebrates, and live rocks that provide flame angels a place to hide and rest.
And all of these will reduce the space in the tank.
So it’s best to keep flame angelfish in larger aquariums that offer more swimming space.
How Many Flame Angels Can You Keep in A Saltwater Aquarium?
Flame Angelfish are peaceful and easygoing. They get along well with other fish.
These community fish prefer to live in pairs or small groups since they don’t want to be left alone.
At the same time, flame angelfish are aggressive toward members of their kind and other similar-looking fish.
That’s why it’s best to keep a pair of flame angels so that they cohabitate peacefully.
How Many Flame Angelfish Can You Keep in A 75 Gallon Tank?
Flame angelfish are primarily peaceful. However, they become territorial and fight with each other during feeding hours.
So keeping them in a large aquarium of 75 gallons or more is recommended.
These fish enjoy exploring every nook and cranny for hidden morsels of food.
Furthermore, having plenty of caves also helps your other fish from frequent pursuits.
Flame angelfish also swim a lot and must be provided space to move around freely.
So it’s best to keep a single pair of angelfish in a 75-gallon marine aquarium.
Keeping more than one pair results in fights.
However, as they can live in a community tank, you can keep them with other fish species in your 75-gallon tank.
How Many Flame Angelfish Can You Keep in A 125 Gallon Tank?
Flame angelfish live in groups called harems in the wild.
So, keep one male and 2 to 6 female angelfish in a 125-gallon tank.
Flame angelfish are stunning aquarium fish, but they don’t prefer to live with their own species or fish that are similar in appearance.
So most people keep a single pair of flame angels.
If you want to keep a group of flame angelfish, you’ll probably need a larger aquarium.
Make sure you have lots of open space and areas inside the tank to place live rocks for supporting algae growth.
Large tanks of 125 gallons or more provide you with an opportunity to emulate their natural habitat.
So, create a reef environment by adding coral, live rocks, caves, and invertebrates.