With the 20 gallon aquarium tanks being such a popular option due to being a great mix between their price tags and the type of fish that you are able to keep in them, we constantly se peopl reaching out with qustions like how many fish can you keep in a 20 gallon tank?
With so many people reaching out and asking for advice on stocking a 20 gallon aquarium with fish as well as the prics of excellnt 20 gallon tank options being much cheaper than they once were, we wanted to publish this article to try and help as many of our readers as possible.
Our hope is that we will be able to help you better understand how many fish you are able to keep in your 20 gallon aqaurium as well as what kind of fish spicies you are able to keep in a community 20 gallon tank too.
With the 20 gallon tank being such a popular beginner aquarium size, many of the people who we see reaching out and asking for advice are brand new to keeping fish so we hope to help you avoid some of the more common mistakes that we see people making time and time again.
We see countless questions each month specifically asking about how many fish from a specific fish spicies you are able to keep in a 20 gallon tank too.
Due to this, we have added our table of contents below to make it as easy as possible for you to navigate the article and get to the specific infomation that you need.
How Many Fish In A 20 Gallon Tank?
You are able to keep between ten and twenty fish in a 20 gallon tank depending on the specific fish species you are planning to keep.
The general rule of thumb of 1 inch of fish per gallon of water in tank is a great way to initially plan out how to stock your 20 gallon aquarium. Just keep in mind, this rule is only effective for fish that are three inches and under and does not apply for fish over three inches.
Following this rule, you can plan to keep around twenty fish that will grow to a maximum of one inch in size like Galaxy Rasboras due to their adult length being so small.
You can also change it up and opt to keep ten fish that will grow to a maximum of two inches in size like guppies or you can opt for around seven fish that will grow to around three inches like Tiger Barbs in your 20 gallon tank.
Although some fish species that are larger than three inches can be kept in a 20 gallon tank, you may want to try and keep one or two of them in there due to the lack of available territory.
Due to the 20 gallon tank size being aimed at entry level fish keepers, it is generally recommended that you stick to smaller fish anyway as they can be much easier to care for.
Fish Stocking Options For A 20 Gallon Tank!
The best fish stocking options for a 20 gallon tank usually include goldfish, cichlids, tiger barbs, platies, dwarf gouramis, betta fish, clownfish, danios, and various types of algae eaters.
You are usually able to mix and match most of these fish species to make a 20 gallon community tank but many people will opt to keep a single species in such a small tank.
Although you are able to keep a range of different fish in a 20 gallon aquarium, we would usually recommend that the majority of our readers who are new to fish keeping stick to the fish species listed above.
They tend to be more beginner friendly, especially with such a small tank and ensure that you will have the easiest possible time at keeping your fish happy.
We will not be taking a more in-depth look at keeping the specific fish species in a 20 gallon tank including how many of them you should keep as well as if you should be mixing them with other fish species or not.
They are all excellent options for a 20 gallon aquarium but each fish species does have their own unique quirks that do have to be factored in.
How Many Goldfish in A 20 Gallon Tank?
The term “goldfish” is used to describe a number of different fish spicies each having their own growth sizes. As different goldfish can grow to different sizes, it is generally recommended that you only keep between five and ten gold fish in a 20 gallon tank.
This leaves plenty of room for growth in your goldfish and ensures that your tank will have all of the space needed for them to live a long and happy life.
If you take the option of ordering your goldfish online to save some money, you will usually be able to find out the exact species of goldfish that you are ordering to workout their maximum lengths as adults.
If you do know the specific species of goldfish that you have then you may be able to stock as many as twenty goldfish in a 20 gallon tank.
Many goldfish species will grow to a length that their tank supports though making it harder to plan how many to keep in a 20 gallon tank.
How Many Cichlids in A 20 Gallon Tank?
You can keep a maximum of three cichlid in a 20 gallon tank due to their larger sizes with two cichlid usually being the recommended number for such a small tank.
Some dwarf cichlid species are smaller than regular cichlids so you may be able to keep up to ten dwarf cichlids in a 20 gallon tank.
The majority of the time though, people want something like convic cichlids in their tank and their larger size will limit the number you should keep to two or three. More and more people are starting to opt to keep dwarf cichlids though like the electric blue dwarf cichlid.
Due to the selective breeding of the electric blue dwarf cichlid ensuring they don’t get larger than around two inches, you can often keep around ten of them in a 20 gallon tank without issue.
There are a number of other dwarf cichlid spicies too that will grow to a maximum of two to three inches that are popular like the apistogramma dwarf cichlid that are proving to be very popular options.
How Many Angelfish in A 20 Gallon Tank?
Some people will keep baby and juvenile angelfish in a 20 gallon tank while they are small but it is not recommended that you keep adult angelfish in a small tank due to their large size.
Most adult angelfish will require a tank height of around eighteen inches and with a maximum volume of 20 gallons, this really doesn’t leave much space for the fish to swim in.
Even a single adult angelfish will probably end up having problems in a 20 gallon tank so we would recommend you try to upgrade to a decent 40 gallon tank to keep two or three angelfish.
If you are breeding angelfish and have multi tank setup then a 20 gallon tank can be a great option for angelfish fry and babies.
You can also keep a number of juvenile angelfish in a 20 gallon tank too while you wait to house them in a larger tank or ship them out to retailers.
How Many Tiger Barbs in A 20 Gallon Tank?
You can usually keep five or six adult tiger barbs in a 20 gallon aquarium without having issues.
Depending on the specific shape of the tank, you may be able to keep seven or eight tiger barbs in the tank but it is generally not recommended in a tank with such a small water volume.
With tiger barbs being so cheap as well as such a beginner friendly fish for people new to fish keeping, they are one of our top recommended fish to keep in a 20 gallon tank.
Just because you can keep five or six tiger barbs in your tank does not mean you have to keep that many either so you can reduce the amount of waste produced by keeping less fish giving you an easier time with tank maintenance.
That said though, tiger barbs are a schooling fish so we would recommend that you keep a minimum of four tiger barbs in your tank if possible. Anything less than that and the fish may experience higher levels of stress and anxiety due to feeling vulnerable.
How Many Platies in A 20 Gallon Tank?
Most people will keep between five and eight platies in a 20 gallon tank without running into any problems.
You can try to keep more in some very specific situations but we would not recommend it and if you have a tall tank with a reduced width then keeping closer to five platies in your tank is probably better.
Platies are one of the easiest fish species to keep in a 20 gallon tank and are one of the more common fish species to stock in smaller tanks no matter the level of experience of the keeper.
Their low price tag also helps make them a great option to beginner fish keepers who are just getting into the hobby too.
Most people will try to only keep female platies in their tank as males can sometimes display aggression to each other, especially in a smaller 20 gallon tank due to there being such a small amount of space available.
If you are trying to actively breed your platies then one male per 20 gallon tank with four to seven females is usually the best option to take.
How Many Dwarf Gouramis in A 20 Gallon Tank?
You can keep as many as five dwarf gouramis in a 20 gallon tank but the majority of people will only keep a maximum of three to ensure that they have enough space in the tank.
You are usually able to get a nice mix of different colors with three dwarf gouramis in the same tank anyway helping to maximize the bright colors and unique patterns of the fish.
There really are a huge number of different colors and patterns available for dwarf gouramis with prices available for all budgets.
The rarer colors and patterns tend to fetch a higher price tag though so some beginners to keeping fish who are looking to keep their costs as low as possible may avoid the rarer colors.
One thing that we would like to point out is that for the most part, dwarf gouramis are peaceful and show little aggression to each other even in smaller tanks.
We often see people new to keeping dwarf gouramis get confused with the higher aggression levels of the standard gouramis so wanted to clarify that they are different fish species with different aggression levels.
How Many Betta Fish in A 20 Gallon Tank?
It is usually recommended that you only keep a single male betta in a 20 gallon tank due to their territorial aggression. Most people will keep around five female betta fish in their sorority in a 20 gallon tank with there rarely being as many issues with aggression female betta fish.
More and more people are switching over to keeping a sorority of female betta fish rather than a single male due to being able to mix and match the various colors and patterns of their fish.
There are some truly unique looking betta fish available for sale online that can retail for up to $50 but you can often find yourself a bargain with unique looking betta fish selling for $20 or less.
It is also becoming increasingly popular to keep an algae eater with betta fish so our article going over keeping an algae eater with a better fish might be worth the read.
It will ensure that you are able to keep the algae growth in your betta’s aquarium under control while also ensuring that there will be minimal aggression from your betta fish to your algae eater.
How Many Clownfish in A 20 Gallon Tank?
A single clownfish is usually recommended for a 20 gallon tank due to territorial aggression between multiple clownfish being common.
A pair of clownfish may work if one will submit to the dominance of the other but there will usually be fishing between the two until the dominant fish is established.
Aggression between clownfish can be common and it is well documented amongst the fish keeping community. We have an article on clownfish being aggressive as well as how to stop two clownfish fighting that may be helpful to you.
With a 20 gallon tank being so small, it is unlikely that you will be able to stop the aggression between clownfish though due to them always having to be so close to each other.
You really do need larger tanks like a 50 gallon tank if possible as it offers more space for multiple clownfish to live with less aggression usually being displayed between them.
How Many Danios in A 20 Gallon Tank?
You are usually able to keep as many as twelve danios in a 20 gallon aquarium depending on the specific type of danios you want to keep. Most people tend to keep between six and ten danios in a 20 gallon tank to ensure that there is plenty of space available for the fish.
A number of danios have gone viral on social media over the last few months due to their unique looks.
Unlike some of the other fish features on our list, the more unique looking danios tend to be cheap making danios an excellent option for anyone who is wanting to keep unique looking, colorful fish in a 20 gallon tank.
You can also mix and match a number of different danio speicies and they will school together in the tank without issue. This can be a great way to keep a number of unique looking fish in such a small tank without having any issues with aggression too.
How Many Algae Eaters in A 20 Gallon Tank?
There are a large number of algae eaters available for a 20 gallon tank and the number of algae eaters that you should be keeping in the tank will depend specifically on what you will be using as your algae eater.
Four nerite snails or ten to fifteen cherry shrimp are excellent options for 20 gallon tanks.
When it comes to the amount of algae consumed for a 20 gallon tank, four nerite snails will probably be the better option for the majority of people.
Due to the rather bland look of nerite snails, a large number of people choose to add cherry shrimp to their smaller tanks instead due to them being a more colorful option.
There really are a huge number of suitable algae eaters for a 20 gallon tank though so going off and researching the different options may be a better path.
Once you have settled on the algae eater that you want, check how many of them can live in a 20 gallon tank without issues.
How Many Ghost Shrimp in A 20 Gallon Tank
You are able to keep as many as eighty ghost shrimp in a 20 gallon tank but the majority of people choose to keep between ten and twenty ghost shrimp.
The less ghost shrimp in the tank the more options you have for other fish, snails, and shrimp allowing you to mix your tank up.
Although ghost shrimp really are seeing a huge spike in their popularity right now, we actually prefer cherry shrimp due to the similar functionality that they offer but wider range of colors and looks.
Depending on what you want for your tank though, ghost shrimp may be able to get the job done.
Some people will mix different type of shrimp in the same tank too with there usually being no major problems.
This can be another way to keep your tank looking as unique as possible due to the unique looks of the individual shrimp, especially if you are able to get a rare purple cherry shrimp.
That brings our article going over how many fish you can keep in a 20 gallon tank to an end. We hope that we have been able to help you better understand your main options as well as how many of those particular fish spicies you should be keeping in a 20 gallon tank. As we mentioned back at the start of the article, you are able to mix and match a fair number of those without issue to add veriety to a community tank.