How Fast Do Plecos Grow? {Will You Need A Larger Tank?}

Plecos are a hardy species of aquarium fish capable of surviving varying environments. It has a relatively long lifespan of about 12 years if they live under suitable conditions. However, they usually grow to full size before their first five years.

How Fast Do Plecos Grow?

Common plecos tend to grow slow up until three months of age, then they usually have a growth spurt and can grow up to 3-5 inches in its first year.

After then the growth proceeds in an almost unnoticeable manner for a few more years until they attain full size. Common plecos usually grow up to 20-25 inches on average.

It is vital to keep the growth rate and the maximum size of plecos in mind while choosing your tank size. Larger tanks will favor the growth of these species of aquarium fishes. Likewise, what you feed them with and other water conditions can also affect their growth rate.

How Fast Do Plecos Grow

Different Types Of Plecos Species

There are different types of plecos species, and most of them vary in sizes. They also vary in their physical structures as well as their average life spans. Even though most of the species and aquarists often refer to them as common plecos, the term is non-specific and rather too general.

However, most of the species that are in the same category with ‘common plecos’ have a lot of features and characteristics in common. It is, therefore, essential to know the exact species you are buying and how large they can grow. The common types of plecos include; Amazon Sailfin Pleco, Sailfin Pleco, Bristlenose Plecos, and the Suckermouth Plceo.

You should understand the size range of each species of aquarium pleco before getting them. This understanding is because this significantly affects how large plecos can grow. While some of them can grow up to 15-25 inches long, some others cannot exceed the 2-4 inches limit.

To be specific, common plecos can grow up to 14 inches long over a relatively long period. Only their first few years of growth are rapid, and other years proceed on a steady level. Bristlenose pleco, on the other hand, can only grow within the range of 4-6 inches over the same period.

What Is the Common Pleco Growth Rate?

The growth rate of a common pleco depends on a multitude of factors in captivity. Generally, it takes about five years for a common pleco to reach its full size.

In the beginning, you will notice the common pleco being able to grow between 3 to 5 in the first year. After this point, the growth rate slows down even further. This is why it could take up to five years for the maximum full-size of 24 to 25 inches to be achieved.

During the first three months, the growth rate is very slow and you may not notice much at all. After three months, you may notice a growth spurt where 2 to 3 inches are tacked on until it reaches about 6 months of age.

Another 2 inches or more can be reached in that first year, but be patient because it’s going to take a long time (5 years!) for your common pleco to reach its maximum length.

How Fast Do Sailfin Plecos Grow?

Sailfin plecos have a fast growth rate compared to many other plecos, but this depends on certain factors such as the food you are feeding. If you are trying to substitute some high protein foods along with the algae and pellets that this pleco is eating, you will be able to help it grow faster.

  • Sailfin plecos grow about 1 inch per month until they reach about 13 to 19 inches in maximum length.

In the first six to eight months they can grow from one inch to 8 inches. This is because it’s common to witness a Sailfin pleco growing at 1 inch per month. If you are not seeing such a fast growth rate, you may need to perform more water changes and consider a larger tank.

If you have aggressive tankmates, you may also be preventing your pleco from growing to its maximum potential. Sadly,  if this Sailfin pleco’s  growth is stunted, the organs inside will still continue to grow which leaves it susceptible to an early death.

Do Plecos Grow to the Size of the Tank?

Is generally a myth to consider that plecos would grow to the size of the tank. A common pleco can grow between 15 to 24 inches, but you should keep them in a tank that is 100 gallons or larger. It’s impossible to the consider that a pleco could grow as large as 100 inches.

On the other hand, you might have to consider the opposite side of the question. If the tank is too small, it’s quite obvious that a pleco’s growth would be stunted. This is an awful occurrence because while the pleco’s body isn’t growing any further in length, the organs within are still continuing to grow.

This means that the organs are pushing against the body and creating incredible amounts of stress within. A pleco’s growth that is stunted with leave it open for premature death or a life that is riddled with disease.

If you have no room left in your tank for a growing pleco, you will have to consider adoption or a larger tank.

Bristlenose Pleco Growth Rate

Bristlenose pleco fry grow slower than many other types of pleco species. They may stay under an inch for the first 3 months and that is common, but after these initial three months, they may hit a growth spurt where an extra 3 inches are added until they it hit the six month mark.

At this point,  the growth rate will slow down to about an inch every 3 months. After the first year, you may only notice a growth rate of an inch every four to six months.

It could take up to 2 years for a bristlenose pleco to reach its full size. Within six months however, a bristlenose pleco can reach full maturity even though it continues to grow.

Daily water changes and adding some boiled vegetables to your plecos morning meals can help this fish grow much faster. Sometimes we are able to create the changes that we want to observe.

Common Pleco Size by Age

A common pleco can live up to 10 to 15 years and reach a maximum length of 24 to 25 inches. The lifespan depends on the way that they are cared for in a tank that is large enough to house them.

Sometimes a common pleco with only grow up to 12 inches only. In other cases, if you have a tank that is over 100 gallons, then you may be able to encourage the maximum growth rate of 24 to 25 inches.

The first 3 months are going to be very slow for their growth. After that by the time, they reach six months  and a common pleco can reach an extra 6 inches in length.

The growth rate will slow down to an inch or two every four to six months. By the time they reach 5 years in age, they will have finally achieved their maximum size and should not grow any further.

Factors That Can Affect the Growth Rate Of Plecos

Just like many other species of aquarium fish, several factors can affect the growth rate of plecos. These factors include;

  • Genetic History: It is essential to know the genetic history of the plecos you want to get. Genes are one of the first things that can determine how big your plecos will grow. Even some common plecos might not grow as big as others because their genes are not programmed to do so.
  • Tank Size and Water Conditions: Plecos grow best when you keep them under a suitable tank and water condition. Right water conditions will make your plecos live healthily, and consequently accelerates their growth. Similarly, plecos need enough space to maximize its growth range—the bigger the tank size, the better for your large plecos.
  • Feeding quality And Feeding Schedule: How well and how often you feed your plecos can go a long way in determining how well they will grow. The feeding habit and feeding rate is particularly influential in the early stages of their growth. Plecos experience accelerated growth in the first couple of years before slowing down later on.
  • Environmental Conditions: Plecos, like most other aquarium species, have their preference for ecological conditions. You should ensure you keep them under conditions that support their growth and make them happy. You should consider key parameters like pH, temperature, lighting, and even tank mates. You can even add plants to their tank to help stimulate their natural habitat and also provide places to hide and rest.
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Caring for Aquarium Plecos

Plecos are one of the hardiest fish that best fit aquariums. They are easy to care for even for beginners, and this feature accounts for why they are one of the most common fish in aquariums. Plecos are freshwater fish, and they are one of the most common algae eaters, scavengers, and bottom feeders. Summarily, plecos can feed on anything.

It is important to avoid overcrowding in plecos’ tank if you intend to keep them safe and healthy. It is essential to create enough space that will allow each fish to have their territories. Enough space will also avoid negative interactions among the members of the tank.

It is also essential to keep plecos with only suitable tank mates. For instance, flat-bodied fish can cause damage to their mouth. Likewise, it is better to house plecos in glass tanks because acrylic tanks can scratch their mouth.

If you want your plecos to grow well and live healthily, you must add gravels or pebbles to their tank. The stones are essential because plecos spend time combing over debris for food. You can also include wood that the plecos can chew.

The temperature of the plecos tank should be between 72-82°F, and they thrive better in the pH range of 6.5-7.5. Before introducing any plecos to your tank, you should know that they require stable water quality. The temperature, pH, ammonia, and salt levels are also crucial to their health.

Finally, if you intend to add plants to the plecos’ tank, ensure you add only sturdy and live plants with fast growth. This choice is because plecos often uproot and eat them. To ensure the survival of these plants, make sure you bury the root deeply in the substrate. You can also consider artificial plants that are not edible for plecos.


Aside from some features that distinguish plecos from other aquarium fish, they also have varying sizes. Plecos have varying sizes that are peculiar to each species. Therefore, it is essential to know the growth pattern of the species you are getting for your aquarium.

Nevertheless, you can accelerate and ensure the proper growth of your plecos if you keep them under the right conditions and if you maintain an appropriate habit of feeding. You should also keep them in a large tank and design their aquarium to simulate their natural habitats.



Hello, I'm Jason. I'm the guy behind I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.

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