How Many Cichlids In A 40-Gallon Tank? The Exact Answer Is Here!

Cichlids are beautiful additions to your aquarium and look more stunning when kept in groups. So how many cichlids in a 40-gallon tank?

Since these fish come in different varieties, we will suggest the best answer for each. Let’s follow our post and set up your tank correctly!

How Many Cichlids In A 40-Gallon Tank?

Generally, one inch of an adult fish requires two gallons of water. If you have a 40-gallon tank, you can raise 5 to 6 mid-sized cichlids.

However, cichlids are available in multiple varieties and sizes. Besides, some of them are aggressive.

You can keep many of these violent fish in the same container, although they are small.

Right here, we mention the size of each variety and recommend the ideal number of them to keep in your 40-gallon tank.

Fish Average size (inches) Number
Demasoni cichlids 4 8-12
Jewel cichlids 6 2
Chindongo saulosi 3.5 6-7
Convict cichlids 4-5 3-4
Dwarf cichlids 2-4 10-12
Ram cichlids 2-3 4
Peacock cichlids 6 1-3
Electric yellow cichlids 4-6 6-7 or 10-11


Demasoni cichlids

Demasoni cichlids rarely exceed 4 inches in length due to their origin in rift lakes in Africa.

In a 40-gallon aquarium, you can put 8–12 of these cichlids, depending on how often you replace the water and how well the filtration system operates.

Do not add fewer than four to five of these. Otherwise, the subdominant male fish will get bullied severely, sometimes leading to death.

Male demasoni may suffer from bullying

Jewel cichlids

A jewel cichlid is pretty big and requires at least 30 gallons of water.

Ten more gallons would be necessary for every new cichlid. Therefore, two jewel cichlids can fit easily in a 40-gallon aquarium.

These fish are pretty eye-catching, as their name indicates. Even when you have a few of them, they still shine.

Chindongo saulosi

The ideal number of chindongo saulosi cichlids to keep in your aquarium is 5 to 7, with 4-5 females and 1-2 males.

Males can be possessive. So, ensure there are no more than one or two males.

These fish display quite a bit of sexual dimorphism. Males have vivid blue bodies with black stripes, while females have bright yellow spots.

Hence, a small group of these fish would surely add some colors to your aquarium.

Convict cichlids

A convict cichlid needs 20 gallons of water. When introducing a new one in your tank, you will need to increase 10 gallons. So, for 40 gallons, you should keep three to four cichlids.

However, these fish may become very aggressive toward their mates. As a result, some species may not always benefit from a 40-gallon aquarium.

Convict cichlids may turn aggressive

Dwarf cichlids

A 40-gallon aquarium can hold 10 to 12 dwarf cichlids. However, keeping the proper water parameters demands extra care.

There are different dwarf cichlids, such as golden dwarf and multies.

They live well with 40 gallons of water. However, expect different personalities in your aquarium.

Ram cichlids

Ram cichlids should live in pairs in a tank of at least 20 gallons. In a 40-gallon aquarium, you can have two pairs or four ram cichlids.

Ram cichlids are famous for being incredibly calm. As a result, you don’t need to be concerned about fighting.

These fish will not fight in your tank

Peacock cichlids

Peacock cichlids can be aggressive; thus, keeping them in a small tank will only intensify their behavior.

These fish often reach a length of four to seven inches. A 40-gallon tank may hold one male and two or three females.

You would at the very least require 55 gallons for a pair of bigger peacocks.

Electric yellow cichlids

Yellowtail acei and yellow labs both have calm personalities. Hence, with these African cichlids, territorial aggressiveness is not a big issue.

Depending on how regularly you can change the water, you may keep anywhere from 6-7 to 10-11 of these species.

These fish are calm

How To Set Up A Cichlid Tank?

Now you know how many cichlids to put in your tank, but your task doesn’t end here. There are some other things to set up.


Sand is the ideal substrate for cichlids, but you may also add coral sand, crushed coral, and shattered oyster shells to keep the alkalinity and pH of the water in your tank at a reasonable level.

Many creatures like digging and sifting in the sand; some even take a small bite to aid with their digestion.


Cichlids generate a lot of waste due to their huge appetites. Hence, ensure the filtration system you install can handle all the waste.

Plants and decorations

Plan carefully to choose the right plants and decorations for an aquarium with cichlids and other species. Many cichlids eat live plants when searching for food.

The best plants to choose are those that can withstand cichlids’ violent habits. Some popular choices include java moss, vallisneria, anubias, and java fern.


Aquarium lighting is crucial for both plant growth and providing your cichlids with a natural day/night pattern.

You will still need to install a light in your tank even if it has no plants. You can learn more stocking ideas from this video:


The number of cichlids in a 40-gallon tank depends on the fish’s size.

5 to 6 mid-sized cichlids can live well in your tank. But don’t forget to check if your pets feel comfortable and get along.

Raising cichlids is not only about determining the correct number to keep. You also pay attention to their behaviors to give them the best living conditions.

Thank you for reading!