How Big Can A Plecostomus Get? Plecostomus Size

The most worrisome thing about Plecostomus is the way they unpredictably grow. If you are someone who is familiar with fishkeeping knows the trauma Plecos can bring to you when it comes to their growth rate. People often prepare a smaller tank looking at their size in the very beginning, unaware of the fact that these small Plecos will grow into a bigger one after a year. I know most of us are not even aware of the fact how big can a Plecostomus get?

Well, if we are talking about their wild habitat, then the size might vary from the one that grow in the aquarium. Plecostomus can grow up to 24 inches big in the wild while remains only 15 inches in the well-maintained aquarium.

There are several factors that decide whether your Plecostomus will grow big or stay smaller than usual. You cannot start a journey of keeping Plecostomus in the home aquarium without knowing these factors.

So, I have written an entire article dedicated to this very topic. And I hope this will make it easier for you to understand what to do next.

With no further ado, let’s dive in.

How Big Can A Plecostomus Get?

The size of Plecostomus varies according to the environment these fish are living in. They can grow bigger when given a proper environment and will stop growing once they find the environment different.

There are many factors that contribute to the smooth growth of the fish. Also, sometimes you play the important role in deciding what actually happens.

The size of Plecostomus varies when they are in the wild and when you keep them in the aquarium life. Each factor that follows the wildlife can be mimic in the aquarium but the size still remains smaller.

Size Of Plecostomus In Wild

If you ever encounter a wild Plecostomus, you will be stunned by its size. Trust me, I was so used to looking at aquarium Plecostomus and always thought these can’t get any bigger.

But how wrong I was when I discovered a full-grown wild Plecostomus. When I asked an expert, they let me know about wild Plecostomus more.

You see, Plecostomus can grow up to 24 inches when they are in their natural habitat. Every living being grows properly and usually is stronger when they are kept in their natural habitat.

Size Of Plecostomus In Aquarium

Now, let’s talk about the change you will see when it comes to wild Plecostomus and aquarium breed. The size can vary so vastly that you will be confused if these two are the same fish.

The Plecostomus that are grown in the aquarium gets 15 inches big and they grow throughout their life to reach this size.

The tank condition and size also determine if your Plecostomus will reach its full potential in the aquarium. Some might remain smaller than 15 inches.

This happens when they don’t get enough room to grow or have a proper diet. Even the small change in the aquarium condition can make a great impact on the growing frequency of Plecostomus.

You might be interested to learn more about 10 Best Large Peaceful Community Fish For Your Freshwater Aquarium

How Fast Can Plecostomus Fish Grow?

When you are aware of the size of Plecostomus and how big they can get in an aquarium, it is necessary to know about their rate of growing into bigger ones.

When you first purchase the baby Pleco from the pet store, they are merely the size of full-grown neon tetra.

You will find a baby Pleco of size 2 to 3 inches during the first purchase and they can even be smaller than that.

However, they won’t remain the same baby ones throughout their life, will they? They live for nearly 15 to 20 years and will keep on growing.

However, the first year is the deciding year for the growth rate of your Plecostomus. Plecostomus grows the most in their very first year of life.

So, don’t get shocked when you see your baby Plecos growing up to 5 to 6 inches within a year. The growth however does continue after the first year too but the rate is slower than the first year.

The growth of Plecos is quite unpredictable and even experienced aquarists face the problem of the smaller tank.

If you want your fish to grow properly and big, then you must look at the rate at which they are growing in the first year.

But do not focus entirely on the first year, as I mentioned earlier, they will keep on growing after the first year too but it will be slower and sometimes unnoticeable too.

How Long Does It Take For A Pleco To Get Full Size?

The length or timespan for Plecostomus to reach their full size depends on how well you are keeping them.

Also, as I mentioned earlier, a Plecostomus can live for nearly 15 to 20 years and are supposedly growing throughout their lifespan.

Most Plecos in a home aquarium live happily for 12 years but reach their full growth potential within the fifth year of their life.

You may get confused with my jumbled words as I am saying two different things at the same time. Let me break it down for you so it gets easier.

They do grow throughout their lifetime and there is no certainty if they will stop. But by the end of their 5th year, they will attain the maximum size they are supposed to grow.

We cannot predict if they will grow further or not but the size they have after 5 years is generally the maximum size.

Factors That Affect How Big Plecostomus Get

I have been blabbering about the factors that can affect and determine how big your Plecostomus can get. That’s why you must be waiting to find out what actually am I talking about.

Many of us already have the idea of how to raise a fish in the tank while some of us are totally good at it.

Fishkeeping can be as simple as you make or as complicated as most people think. Once you get a grip of what to do next, you will never fail in this hobby.

Water parameters, diet, proper attention, care, and love are what make one fish the healthier. You may not understand this if you are a beginner but trust me every fish is different.

Here I will let you know the important factors that will directly affect the growth rate and frequency of your Plecostomus.

Tank Size

A spacious tank where there is always room for growth plays the main role in deciding how big your Plecostomus will get.

I have always wondered how a small 3 to 4 inches sized baby Pleco needs such a bigger tank. But I was proven wrong when I saw my Plecostomus overgrowing the tank.

I had seriously had a bad heartbreak while I was handing over my healthy yet overgrown Pleco to my friend.

I was a beginner back then and underestimating the importance of tank size for Plecostomus was one of the first common yet beginner’s mistakes I made.

So, I don’t want you to repeat the same thing I did. Here is what you need to do. And please do not count changing the tank once they get bigger as an option.

You will at least need a 55-gallons tank for a single Plecostomus to grow properly. If you are planning for 2 or 3 of them, then go for more than 80 gallons tank.

Here is an article on How To Set A 50-Gallon Fish Tank?

To be honest, if you are serious about keeping a few of them, a 150-gallons tank is undoubtedly an ideal choice.

You need to, however, make sure the filtration system and the aquarium beneficial bacteria are doing their work properly.

These fish tend to get quite messy and produce a lot of waste. The tank size might be the determining bacteria but a dirty tank will surely make the game over.

You might like to read more about

Why Do Fish Tanks Get Dirty So Fast – How To Clean And Maintain Tanks


The growth of any living beings depends on the food they eat. Even if it is a microorganism living in the host body or human being, all living beings need a proper diet to survive and grow.

Plecostomus is an omnivore and hence they will eat both meat and plants. These characteristics of Plecostomus give you a window to feed them so many things.

They don’t like to eat the same food every day so you need to be careful with their eating schedule and menu.

If you really want your Plecostomus to reach as big as possible, then go for food with a high level of fiber. Zucchini, lettuce, shelled peas, cucumber, and spinach are some great vegetables to feed your Plecostomus.

Also, as I mentioned earlier, they are omnivorous so it is better for them to have some fleshy diet too. You need to go for bloodworms more precisely than other live foods as these Plecos love bloodworms immensely.

If you want to go for some store-bought food, then feed them pellets that sink in the bottom of the tank. These bottom feeders will appreciate it.

You must remember to feed them daily with a certain amount of food without missing a day. Also, make sure you are not overfeeding them, or else you will end up with obese fish rather than the big one.

Plecostomus will only eat when there is no light on and it is necessary to understand their every need. A simple miss can make your fish unhealthy and even kill them.

So do not forget to alternate the food every day. As the same type of food daily can make anyone lose their appetite and rebel.

Read an article on Fish Food 101: A Beginner’s Guide On How To Feed Aquarium Fish

Hiding Spots

Keeping a nocturnal and darkness-loving living being in a well-lit environment with no spots to hide is quite cruel, don’t you think?

If you are interested to see or observe the activities your Plecostomus does, then it is better to look for them when you turn off the light.

They don’t prefer light and stay hidden when there is any kind of light making their way. So, if they don’t have enough spaces where they can hide during the daylight, these Plecostomus will start to get stressed.

The uncomfortable feeling along with the stress will make the life of your Plecostomus miserable. They will start to lose their appetite and will act irrationally in the tank.

This will not only make them weak and unhealthy but also hinder the growth rate of Plecostomus. So, you have to make sure they have enough spaces to hide and stay during the daylight.

Algal Growth

Do you know Plecostomus are famously known for their love for algae? Yes, my friend you read it right. These fish are so in love with algae that they won’t leave any behind.

These Plecostomus are like two-in-one deals where you get a fish for your fishkeeping hobby while it also helps you get rid of algae in the tank.

They love to feed on algae so you need to make sure there are some algae growing in the tank. These fish need something to keep them busy while they graze through the bottom.

However, keep in mind that uncontrollable algal growth can change the entire ecosystem and water parameters of the aquarium.

You need to keep in mind the more your Plecos eat in the tank, the more they will create a mess. You need to have a good aquarium filtration system as well as a controlled algal growth.

A little growth of algae will be like a playful snack for your Plecos. And their presence apparently makes the Plecos feel more comfortable within the tank.

I know it may sound absurd but if you have a community tank that has a high level of algal growth you can get Plecos.

They work or better to say eat as a miracle worker when it comes to making a tank free from algae.

Here is an article on How To Get Rid Of Algae In Fish Tank Naturally?

Hiding Places

Get some new dose of knowledge from here Aquarium Decorations: What To and What Not To Add – Beginners Guide

What To Do With Your Overgrown Plecos?

FIRSTLY DO NOT MAKE ANY STUPID MISTAKES OR OVERBOARD WITH SOLUTIONS. If your fish has overgrown the tank, then this might be your mistake in the first place for underestimating the growth rate of Plecostomus.

Let bygones be bygones and let’s think about what to do next once you see your Plecostomus is getting big each day and space getting smaller.

What Not To Do With Your Overgrown Plecostomus?

First of all, I will tell you the list of things you should not do while your Plecostomus is overgrowing in the tank.

Do not drop them back into the wild if your Plecostomus is big enough to not fit in the tank. Aquarium-bred Plecostomus are adjusted and adapted to live in captivity where every little thing is well-maintained and taken care of.

They will not be able to survive in their natural habitat as it would be an entirely new environment for them.

Can you imagine spending 1st half of your life in Africa and then going back to live in the North Pole? Even the Santa Claus who lives in the polar region chooses the coldest night of the year to visit the world.

So, if a mystical character like Santa Claus cannot survive the temperature change, how can you possibly imagine your fish living in a completely new environment?

Things To Do With Overgrown Plecostomus

Now, that being said and the fact that you cannot and should not keep your Plecostomus in a smaller space, you need to make a certain plan.

If you want to make a profit out of this, then there are many buyers who would happily buy bigger Plecostomus from you.

Find a potential buyer and make sure to check if they have a well-maintained and bigger aquarium. Sometimes it is a real trauma to search for someone who is interested to get a bigger Plecostomus.

So, you can ask the pet stores near you if they are willing to take a bigger Plecostomus for breeding purposes.

There is another thing you can do if you have few dollars to spare. You can get a bigger tank for your Plecostomus and cycle it properly (which you should have done in the first place).

If you don’t prefer either of these ideas, do what I did back when my Pleco grew weirdly big and made the aquarium smaller for itself.

I asked my friend who had a bigger aquarium at home to take and pet my dear Plecostomus. To my surprise, he happily obliged.

He was excited to have a new addition in his home aquarium. I was happy to find a new home for my fish and the idea of getting to meet it whenever I can.

Find a friend or acquaintances who will happily raise and keep your Plecostomus in their bigger aquarium.

Frequently Asked Questions

I know the questions don’t end here and the queries never get over. So, I have tried to put together some of the FAQs and answer them in order to make it a little easier for you.

What Fish Can Plecos Live With?

If you know the type of fish Plecostomus is, it will easier for you to choose its tank mates. Despite the big size, these fish stay at the bottom and eat whatever you give them.

These Plecos are omnivorous and bottom feeders hence, they won’t be disturbing any other fish in the tank. You can go for smaller ones or slightly bigger ones but make sure they are fast-moving mid or top dwellers.

I will let you in on the fish that I personally have in the tank with Plecos. For the past year or 2, I have been raising Plecostomus and angelfish together in the same tank. There are few other names too.

You can go for cichlids, bettas, barbs, gourami, loaches, mollies, platies, hatchets, and even some species of catfish.

But before you decide or drop any fish in the tank, make sure you research well and learn about their compatibility and their tank requirements.

You might end up losing your new fish while you are busy taking care of your Plecostomus. Make sure to treat each of them equally.

Can A Common Pleco Live In A 55 Gallon Tank?

Yes, you can keep common Pleco in a 55-gallon tank but there is a catch to0 it. Although common Plecos can attain the size of 15 inches in the aquarium and 24 inches in wild, they will need a much bigger tank irrespective of their size.

They will live happily in a 55-gallon tank only if the filtration system is top-class and always cleans the tank leaving no mess behind.

You might already know how messy your common Pleco can get and how necessary cleaning is. But remember to keep only one Pleco in a 55-gallon tank.


In conclusion, Plecostomus is one of a kind and can grow really big. It will not be their fault if you are not prepared well enough for their unpredictable growth. You know it is always better to plan one step ahead and go for a bigger tank in the first place. This will help you prevent the situation where you run searching for a new home for your overgrown Plecos. The real deal is to know how big Plecostomus can get and what is ideal for them

Do not compromise or go small if you really want to keep Plecostomus in the home aquarium. Because trust me they can get really big when you give them ideal water parameters and diet.

Love can do wonder. And here the most wonderful thing would be a Plecostomus that get big to their full potential.

If you still have queries related to Plecos or any other fish, drop a comment or check other articles on this site. Trust me, I will try to get back to you as soon as possible.

Good Luck!!!

Happy Fishkeeping!!!

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