How Many Cichlids In A 20-Gallon Tank?

I know when you fall in love with a certain type of fish, you can’t get over it easily. All you want to do is bring them from the pet store and keep them in the home aquarium. And when it comes to cichlids, I mean wow. Those varieties of cichlids can be a real blessing for your eyes as well as your house. But, when you can’t think or keep a bigger tank at your home, you tend to think about keeping fish in a smaller tank. Although a 20-gallon tank is not considered small cichlids can be a little confusing. So, you need to know how many cichlids you can keep in a 20-gallon tank. Which cichlids can you actually keep in a 20-gallon tank?

Well, cichlids can be big and small depending on their type. So, you may not be able to keep more than 2 to 3 cichlids in the 20-gallon tank even when you go for smaller cichlids. Convict cichlid, cockatoo cichlid, and Kribensis cichlid are few cichlids you can keep in a 20-gallon tank.

Keeping cichlids in a 20-gallon tank will be a problem because most of them need tanks bigger than 55 gallons. So, we need to learn more about the cichlids that can fit in a 20-gallon tank.

You might have more questions about these cichlids and their numbers in the 20-gallon tank. So, I have written a whole article dedicated to this problem.

So, let’s dive in.

How Many Cichlids In A 20-Gallon Tank?

Most cichlids are way too large for a 20-gallon tank as they belong to one of the largest fish families. So, I can’t think how you will adjust some of the cichlids in the tank.

For let’s talk about the few, you can actually keep in the 20-gallon tank despite the size. You see there are few types of cichlids that will make themselves comfortable in confined space.

However, their number cannot exceed more than 2 because their size doesn’t allow them to live with more.

I know you want to keep many cichlids together in the tank. But cichlids tend to be territorial and won’t let anyone else within their space.

Some of the smallest cichlids like Multie, a shell-dwelling type, will be happy in the 5-gallon tank. So, don’t worry about not being able to keep many cichlids in the 20-gallon tank.

What Is The Ideal Tank Size For Cichlids?

Well, as I told you already most of the cichlids are quite large. So, their tank requirement is quite bigger than what you are planning to keep.

Most of the cichlids do well in the tank larger than 55-gallon. While some of the cichlids are way larger and need a tank with more than 120-gallon capacity, there are few smaller ones that will be happy in a 20-gallon tank too.

The ideal tank size depends on the type of cichlid you are planning to keep. Each of them has different requirements and you will be surprised to find varieties within one family.

How Many Cichlids Per Gallon?

Well, to be honest, the size of your fish might be the prime factor for deciding the gallon of water it needs in the tank, but its territorial behavior plays a key role in locking the decision.

Most cichlids are more than 4 inches in size. So, if we go by the golden rule of 1 gallon per inch, most cichlids will need more than 4 gallons of water per fish in the tank.

But, cichlids will not be happy with 4 gallons of water per fish because they are territorial and will ask for most of the space in the tank.

So, if you are planning to raise cichlids, then go for bigger tanks with a water holding capacity of more than 55 or 120 gallons.

However, there are few cichlids that are smaller in size and will be fine with 5 to 6 gallons of water for each of them.

But again, the territorial issue can intervene, thus it is better to give each cichlid more space than their size asks for.

Research well for the types of cichlid you are planning to keep or the one you fell in love with. Do not keep any of the cichlids in the confined space or the smaller tank than they prefer.

Which Cichlids Can You Keep In A 20-Gallon Tank?

There are few smaller cichlids that will happily adapt and adjust to the life of a 20-gallon tank.

You have to make sure there is everything these cichlids will need to survive in the 20-gallon tank.

Or else, you might have to have a faceoff with consequences despite the appropriate size of the tank.

And you cannot keep more than 1 pair of each of the cichlids in the tank as small as 20-gallon.

Ram Cichlids

When we are talking about Ram Cichlids, you can go for 1 male and 1 female in the 20-gallon tank.

The female number can go up to 2 but the male number needs to remain one. The male-to-female ratio should always be 1:2 when you are keeping a smaller tank.

Convict Cichlids

Again, you cannot exceed more than a pair of these cichlids in the 20-gallon tank. You may have to face consequences if you try overstocking them.

Kribensis Cichlid

The same story again, you can keep a pair of this cichlid in the 20-gallon tank. We can keep a pair of these Kribensis Cichlids in the tank with no problem or issues whatsoever.

Agassizi’s Dwarf Cichlid: Apistogramma Agassizii

Our dear Apistogramma Agassizii is probably one of the most undemanding cichlids you can get. And keep a pair of these Agassizi’s Dwarf Cichlid in the 20-gallon tank.

Cockatoo Cichlid: Apistogramma cacatuoides

Now coming to another type of cichlid that is also quite smaller compared to other cichlids. You can keep cockatoo cichlid in the 20-gallon tank but their number should be 2 or less than 2.

Another Apistogramma you can keep in the 20-gallon tank is Apistogramma cacatuoides. But the number will vary a little than Apistogramma Agassizii.

You can go for 1 male and 2 females for these cichlids when you look for cichlids to keep in a 20-gallon tank.

Umbrella Cichlid

A pair of umbrella cichlid will do great in the 20-gallon tank but do not exceed the number. Overstocking these territorial cichlids can cause some serious damage to fish as well as the tank.

Dwarf Cichlid

Neolamprologus multifasciatus are the smallest cichlids you will find and probably be the easiest for you to keep. You can keep nearly a colony of them in the 20-gallon tank.

You can nearly keep 10 to 15 of these dwarf cichlids in the tank. Thanks to 2 inches size of the male dwarf cichlids and less than 1-inch size female dwarf cichlid.

Why Can’t You Keep Bigger Cichlids In A 20-Gallon Tank?

Well, can you stay in a confined space where you can’t move your hands and legs? I don’t think so. Thus, you can’t expect cichlids to stay in a tank that is not appropriate for them.

The confined space cannot handle bigger fish. These cichlids love to swim around and prefer fun activities.

But bigger cichlids will have a problem staying in a confined space. Hey, you can’t keep larger cichlids with 120-gallon tank need in a 20-gallon tank.

Where did the 100-gallon go? Come on, you can’t be that cruel.

Keep bigger cichlids in a bigger tank and designated cichlids in the 20-gallon tank. Don’t force impossible things to happen.

What Happens If Overstock The 20-Gallon Tank With Bigger Cichlids?

I know you might be wondering about the consequences of overstocking I have been babbling about.

And trust me when I say this, the end product of overstocking a tank is never something you would prefer seeing.


How would you feel when you are in the middle of a small room with 100 people? You will feel the suffocation due to overcrowdings.

The same happens in the tank with cichlids when you overstock the 20-gallon tank more than it is said to be.

High Waste Production

Cichlids when more than necessary will produce way more waste than a tank can handle. Hence the aquarium ammonia poisoning might intervene killing your fish.

Dirty and foamy aquarium water can kill any fish after the pollutants level reaches a certain point.


Territorial fish will bully each other to make them stay away from their safe space. So, in a small space of a 20-gallon tank, there will be a high chance of bullying and winning over females with some petty act and fight between males.


Cichlids are mostly territorial and when they see some other cichlids in their safe space, this can stress them.

They will feel vulnerable and you might see some aquarium fight between two egoistic male cichlids.

They will injure each other during the attack and you might end up losing the weaker fish.


When you keep a greater number of cichlids in the 20-gallon tank, they will start to suffocate each other due to overcrowding and small space.

Frequently Asked Questions

I know the questions related to fishkeeping are never-ending and finding answers to each of them is quite nerve-wracking.

So, to make your suffering less painful, I try to answers some of the most asked questions related to a 20-gallon tank and cichlid.

What Is The Best Fish For A 20 Gallon Tank?

If you really want to keep a 20-gallon tank rather than a bigger tank, you might like to look for other options.

Trust me there are so many fish that will happily adjust in the 20-gallon tank, blessing you with the best aquarium.

I will name a few of them so you can research them more and choose the one you will absolutely fall in love with.

  1. Neon Tetra
  2. Mollies
  3. Guppies
  4. Zebra Danios
  5. Cardinal Tetra
  6. Ember Tetra
  7. Cory Catfish
  8. Swordtail
  9. Dwarf Gourami, etc.

Do Cichlids Need Light At Night?

No, Cichlids don’t need light at night. Coming from the deepest lakes, they are used to living in dark and murky conditions.

A tank full of plants, decorations, as well as algae will be great for them and lighting also needs to be the same as their natural habitat.

And natural habitat means light during the day and darkness throughout the night. They will grow properly and with their full potential when you replicate their natural habitat in captivity too.

What Temperature Is Best For Cichlids?

African cichlids come from the tropical environment and are used to warm water. So, you need to replicate the same temperature in the tank if you want them to grow mentally as well as physically.

The ideal temperature cichlids ask for is between 78 to 82 degrees Fahrenheit. You might need to get a heater for this very purpose. And while you are at it, go for an aquarium heater with an output of 5 watts per gallon of water.

Make sure to not fluctuate temperature more often and cichlids too can be sensitive to the constant change in their environment.


In conclusion, it is better to get a bigger tank when you are planning to keep cichlids. A big spacious tank is what cichlid needs to be happy in captivity. Overcrowding and small space will suffocate and stress your cichlids and you might be able to raise them in the tank. Research well about the types of cichlids you want to keep in the tank and prepare accordingly. A simple mistake can lead to the death of your fish and make you a failure in fishkeeping.

Fishkeeping is no rocket science rather it is simpler than raising other pets. All you have to know are the simple rules and procedures while preparing and after keeping the fish in the aquarium.

Go for the 20-gallon tank if you really want to keep cichlids but with only the cichlids I suggested.

I know you will do great. If anything comes up, let me know. I am here to help.

Good luck!!

Happy Fishkeeping!!!

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