How Many Angelfish In A 10 to 75 Gallon Tank? Here’s A Guide

Angelfish are certainly one of the most beloved types of freshwater fish. Angelfish are schooling fish that require at least a 10-gallon aquarium tank. They are usually peaceful, but may nip the fins of other angelfish. Angelfish are also lovingly referred to as Angels in the fish community. Some people say that angelfish got their other name “angels” from the angel-like shape they have.

So what size tank do you need to house these angels? Knowing the perfect freshwater aquarium tank size is crucial for their good health and survival.

What size tank do angelfish need on average?

Angelfish are usually quite big by the time they’re adults. Tall aquariums will make the best choice to accommodate their angel-like body shape. 

In a 10-gallon aquarium tank, on average, one male or female angelfish can fit. The male angelfish usually has a larger size than the female angelfish. For example, if we were talking about a 29-gallon tank, two adult male fish would comfortably swim around while three adult female angelfish would be able to swim around and still have plenty of room.

how many angelfish in a gallon tank

Here’s a table for finding how many angelfish can go in a tank:

Tank SizeNumber of Angelfish
10 Gallon (37.85 litres)1
20 Gallon (75.70 litres)2
29 Gallon (109.77 litres)3
30 Gallon (113.56 litres)3
40 Gallon (151.41 litres)4
55 Gallon (208.19 litres)6
60 Gallon (227.12 litres)6
75 Gallon (283.90 litres)7

It is important to know the two assumptions I’ve made in calculating the number of angelfish you can stock in a tank:

  1. The fish should be able to move around freely in the tank.
  2. There’s some cool decorations in the tank.

What happens when too many angelfish are put in a small gallon tank?

Placing too many angelfish in a small gallon tank results in overstocking. And overstocking is bad.

Why? The excess poop in the tank will increase the concentration of harmful nitrites and ammonia. If fish or other aquatic animals are exposed to these substances, they can cause water to become cloudy and unsafe for them to live in.

So, for creating a healthy environment for the angelfish, only one angelfish per 10 gallons of the tank should be placed. 

Overcrowding angelfish in small tanks can cause them stress. Such a situation leads to a slowdown in the growth rate of angelfish. The more crowded the tank, the easier it is for the angelfish to spread harmful diseases to each other.

Therefore, a smart angelfish owner should stay away from trying to squeeze just a couple more angelfish. 

What will happen if there are too few angelfish in a large gallon tank?

It is important to keep a certain number of angelfish in a large gallon tank to maintain balance in a tank. If too few angelfish are present, then the fish population will be overpowered by an overgrowth of algae, which will negatively impact the ecosystem. This lack of balance will lead to the angelfish population to dwindle.

Too few angelfish in a large tank also means your angels get bored. Angelfish are extremely curious and enjoy the novelty of the aquarium pretty well. Boredom has a great influence on the angelfish’s brain and behaviour.

Angelfishes need certain amount of stimulation, which they will not get in an empty tank. This lack of stimulation can sometimes lead to health issues such as depression. 


  1. How many angelfish in a 125-gallon tank?

    In a 125 gallon tank, around 10 to 12 angelfish can fit in depending upon the availability of free space and the type of décor in the gallon tank.

  2. What is the minimum size of a tank for angelfish?

    The minimum size of a tank for an angelfish will be 10 to 20 gallons. A 30-gallon tank for angelfish would even be better, since it allows room for decor and aquarium novelty.

  3. Can you just keep female angelfish in a tank?

    Yes, you can just keep female angelfish in a tank. Having a female angelfish tank is a much better option because they are more peaceful than male angelfish. The female angelfish are only aggressive when they are mating or protecting their eggs.

  4. Can you just keep male angelfish in a tank?

    Yes, you can just keep a male angelfish tank. However, the male angelfish have aggressive nature. They might fight a lot and may nips at other fishes in the tank. They may also damage the décor of the tank.

  5. Do angelfish need to be in groups?

    Angelfish tend to be the best whenever they are in a group of four to five angels on an average.