Most pleco species are large and need a lot of space to swim freely. So, how many plecos per gallon of water can you keep?
The number of plecos per gallon depends on the pleco species. Depending on the species, a pleco tank can vary from 40 to 150 gallons per pleco. Plecos like common plecos grow up to 15 inches, while others like bristlenose plecos grow up to 6 inches. So the number of plecos per gallon also varies.
There are more than 150 pleco species, each having a different housing requirement. So let’s learn more about this.
Ideal Tank Size For Various Pleco Species
Plecos come in various sizes ranging from small aquarium species to larger pond dwellers.
So their tank size requirement varies as per the species.
Let’s now try to understand the ideal tank size for the most common aquarium plecos.
Tank Size For Large-Sized Plecos
The below large species of plecos need comparatively large tanks with ample space to move around.
1. Common Plecos
Common plecos are the most popular fish kept in aquariums. These fish are hardy, easy to care for, and fun to observe.
In captivity, the average size of fully grown common plecos is around 15 inches.
However, they’re known to grow as large as 24 inches in their natural habitat.
Many aquarists go wrong with the tank size while housing common plecos.
Since these fish are sold when they’re young, aquarists think a small tank is sufficient.
However, they can quickly outgrow a small tank once they start growing.
So a single common pleco needs a tank of at least 80 gallons.
However, to help your common pleco reach its full potential size, a large tank of around 150 gallons is recommended.
2. Sailfin Plecos
Sailfin plecos are known for their body coloration. They sport a highly-condensed series of spots that cover their entire body.
The average size of sailfin plecos is 13 to 19 inches in length when fully grown.
So they need a relatively large tank of at least 100 gallons.
A large tank also helps sailfin plecos grow to their fullest size and curbs their aggression, thus keeping them stress-free.
3. Blue-Eyed Plecos
Blue-eyed plecos are one of the rarest species in the aquarium community. They were pretty popular during the 1990s.
However, they’re now rarely found in the aquarium trade as you can only find wild fish in Colombian rivers, which are now outside the Columbian government’s control.
Bue-eyed plecos can grow up to 16 inches when kept in ideal conditions similar to their natural habitat.
They need a minimum tank size of 180 gallons.
The tank size should ideally be larger than this to accommodate other fish and tank equipment.
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4. Vampire Plecos
Vampire plecos are famous for their unique and intriguing appearance.
They have unique eyes that dilate according to the light intensity levels, which helps their vision at night.
These fish can grow up to 10 inches once fully grown. So, you need a tank of at least 50 gallons for a single vampire pleco.
However, a large tank of 75 gallons is recommended for vampire plecos as they need ample space to swim, scavenge, and explore the surroundings.
5. Royal Plecos
Royal plecos inhabit the Amazon Basin. They look very intimidating due to their vibrant colors.
Royal plecos tend to be a bit larger than other pleco species. So their movement is limited.
The average size of royal plecos ranges between 16 to 18 inches in length. However, some of them grow even larger.
For example, Black Royal Plecos can grow up to 24 inches when kept under the right conditions.
So royal plecos require a sizeable tank of at least 125 gallons.
Besides, the tank width should be at least 24 inches from front to back.
This is because they’re not strong swimmers.
Royal plecos can also have difficulty turning and exploring the tank due to their large size if they’re cramped for space.
6. Sunshine Plecos
Sunshine plecos are favorites among aquarists for their vibrant coloration that can last throughout their life.
However, their vibrancy can change if the water conditions are poor.
Sunshine plecos are around 3.5 inches when they’re a few days old. However, they can grow up to 12 inches when fully grown.
So the ideal tank size for housing a fully grown sunshine pleco is 125 gallons.
A large tank keeps them stress-free and helps in their optimum growth.
Tank Size For Small-Sized Plecos
While plecos are considered one of the largest freshwater species, some plecos stay small in size, even in their adult years.
Given below are the smaller-sized plecos that are an excellent choice for home aquariums.
1. Bristlenose Plecos
Bristlenose plecos are the most popular pleco species as they’re friendly, hardy, docile, and adapt quickly to most water conditions.
The natural habitat for these fish is the fast-flowing rivers in the Amazon Basin.
You can mimic their natural environment as closely as possible in the aquarium to ensure they live a happy and healthy life.
The average size of bristlenose plecos is 3 to 5 inches.
However, they can grow up to 8 inches in length in a captive environment under extreme care on rare occasions.
A minimum tank of 30 to 40 gallons is required per bristlenose pleco, with an extra 10 gallons of water per additional fish.
2. Rubber Lip Plecos
Rubber lip plecos are an excellent choice for beginner to expert aquarists.
They’re usually very peaceful and don’t bother their tankmates.
However, rubber lip plecos can get aggressive over territorial disputes with similar-looking catfish.
The average size of rubber lip plecos is between 5 to 7 inches. So you can keep them comfortably in a 30-gallon tank.
The tank should have more vertical swimming space as rubber lip plecos are very active when they forage for food.
3. Zebra Plecos
Zebra plecos are popular for their unique appearance. Their stripes resemble those of zebras.
Zebra plecos can grow up to 4 inches once fully grown.
Due to their small size, a 30-gallon tank is ideal as it provides ample space to swim freely.
You can also decorate the tank with multiple caves and driftwood and keep them in a small group without worrying about territorial issues.
4. Clown Plecos
Clown plecos are relatively low-maintenance species that can thrive for a decade in captivity under favorable living conditions.
Clown plecos do well in tanks with driftwood as it acts as a food source and a good hiding place.
The average size of clown plecos is around 3 to 4 inches.
Although they’re not large, clown plecos can get territorial if cramped for space.
A minimum tank size of 20 gallons is essential for clown plecos, with extra 10 gallons for every additional fish.
5. Snowball Plecos
Snowball plecos are unique due to their distinct coloration.
Their bodies are covered with yellow and white spots that create a unique pattern.
Snowball plecos usually hide a lot as they come from a dark environment.
They like dark caves covered by plants or driftwood in their tank.
The average size of snowball plecos is around 5.5 to 6.5 inches in length when fully grown.
These fish can do well in a 40-gallon tank.
However, if you’re housing them in a community tank, the tank should be large enough to accommodate all the fish.
6. Leopard Frog Plecos
Leopard frog plecos are also known as Imperial Tiger plecos. They’re hardy fish that adapt well to various water conditions.
The average size of these fish is between 3 to 4.5 inches. Due to their tiny size, a tank of 30 gallons is sufficient.
However, a bigger tank is more suitable, especially if you intend to have a community tank with multiple fish species.
7. Candy-Striped Plecos
Candy-striped plecos are found in aquariums worldwide due to their attractive coloration.
They’re natural bottom-dwellers that do well in heavily decorated tanks with rocks and driftwood.
Candy-striped plecos don’t grow very large. They can grow up to 4 inches in captivity.
A minimum tank of 20 gallons is essential to keep them healthy.
The tank should also have space for decorations to make the fish feel comfortable.
8. Butterfly Plecos
Butterfly plecos are popular for their ability to camouflage.
When kept in captivity, these fish can change their color to match the substrate.
They have a healthy appetite, and hence a strong filtration system is essential.
Butterfly plecos can grow up to a maximum of 6 inches in length.
The minimum tank requirement for a single butterfly pleco is 40 gallons.
Keeping butterfly plecos in a small tank can stress them and affect their immunity.
Can You Keep Multiple Plecos Together?
You can’t keep multiple plecos together.
Once plecos reach maturity, they don’t get along with each other and are highly territorial when housed in the same tank.
The other reason for not housing multiple plecos together is that some pleco species grow very large and need ample space in the tank.
So when they’re placed together, they will fight with each other if their territory gets invaded.
However, there is one exception.
A pair of plecos can sometimes flourish if housed together since birth.
The tank should be massive for both the plecos to claim their territory.
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What Happens If Pleco Tank Is Overcrowded?
Overcrowding can have adverse effects on the health of plecos.
Overcrowding leads to stress, stunted growth, and lower immunity, making the plecos more prone to diseases.
Another problem associated with overcrowding is the risk of aggression among plecos.
Plecos can become territorial if cramped for space or another fish encroaches on their territory.
An overcrowded tank also holds less oxygen, and the water can get contaminated faster than usual.
Poor water quality and less oxygen level can stress the plecos.