Common Pleco (Plecostomus): Care, Size, Lifespan, breeding, & More

The Common Pleco (AKA plecostomus) is a unique-looking freshwater fish that it’s huge size will draw the attention of any bystander to your tank. They are large fish with unique patterns that make them very different from other aquarium species. They are one of the first types of plecos kept in the aquarium hobby. In fact, the term “Pleco” originated from their scientific name “Plecostomus”. Caring for this fish is relatively straightforward and simple. They’re easygoing and friendly fish but will grow very large which makes them a little hard to keep.

This article will walk you through all the information you need to know about Common Pleco care and many more tips and tricks to make an ideal living space for them.

Species Profile & Overview

The Common Pleco (L021) is a freshwater species that is widely available in most pet stores. They are sold when they are very small which some new aquarium owners might get for their smaller tank not realizing that these fish will soon outgrow the tank. If you have a large tank or tropical pond that has algae problems, we highly recommend getting them. 

This fish, like all its family members, has an armored back that is designed with a dark green base color that has lighter patches and dots. Depending on the age and size of the fish the color and patterns might slightly differ. 

That being said, these are some of the most popular types of plecos for large tanks and ponds. Despite their large size, they are shy and mostly active during the night. So it’s important to provide them with lots of hiding spots and caves so they can relax during the day.


Common Pleco

Common Pleco’s size and color make them stand out in an aquarium or pond. No matter what type of fish they share a tank with, they will still grab viewer’s attention to themselves.

They do not have scales, instead, they are covered with hard bone plates that cover their entire back. The belly area is soft and has a thin layer of skin that is slightly brighter than the rest of the body. On their back, their eyes are the only soft spot they have which makes them vulnerable to aggressive fish.

Anatomy Of Plecos

As seen in the figure above, they have 8 fins in total, fins have a triangular shape that shares the same colors as the rest of their body.

Adult Size

The average Common Pleco size in captivity is about 15 – 16 inches in length. This means they are one of the bigger plecos that will outgrow most aquariums. So you should only keep them if you have a large aquarium.

They are relatively fast growing plecos, so you might soon need to get a bigger aquarium if you purchased them for a small aquarium.


In captivity, Common Pleco lifespan is around 10 – 15 years. This is only possible if you give them proper care and diet. Bad diet, low water quality, and stress will reduce their lifespan drastically.

Behavior and Temperament

Common Pleco aren’t very social and outgoing fish. They are mostly at the bottom of the tank hiding somewhere under rocks and decorations when the lights are on or it is daytime. These fish are mostly active during the night and will look around for food.

Having said that, you will also see these fish come out during the day or when the lights are turned on. This generally occurs when they are hungry or when it has been accustomed to the environment of the tank and feels safe to come out.

If more than one pleco is present in your aquarium, they might fight over their favorite cave or hiding spot. To avoid any aggressive behaviors, you should have a large aquarium that has lots of hiding spaces. If they still fight with each other, you should move one to another aquarium before they injure themselves.

Common Pleco Care

Common Pleco care is easy and simple. Despite coming directly from the wild to your aquarium, these fish adapt well to life in the aquarium. As long as you can manage to keep your aquarium to the minimum parameters they need, it will thrive.

However, that doesn’t mean that Common Pleco doesn’t need special attention. They will still need clean and warm water with a rich diet made especially for this pleco. They will develop diseases that will reduce their lifespan if water quality and diet are not in their favor.

To create an ideal environment for your Common Pleco you will need to follow the recommendations mentioned below.

Tank Size

The minimum tank size for a single Common Pleco is 120 gallons. Juveniles can live in smaller aquariums but we do not recommend doing this unless if you are planning to upgrade soon. Large tanks are generally easy to care after and are able to maintain more stable water parameters in comparison to smaller tanks.

We do, however, suggest getting an even larger tank if possible. This is especially true when you want to house more plecos in a tank.  Naturally, larger tanks will give your fish more floor space where your plecos can hang around and call home. A further benefit of having a larger aquarium is that its parameters will be more consistent. This is probably the most important factor in keeping fish. 

Ideally, a tank that has a more flat surface area is better than a tank that can hold more water. This means a wider aquarium is much better than a tall aquarium as it provides your fish with more floor space. You will also have more space to decorate and create even more surface and hiding spots.

Tank Setup:

In your aquarium, you will need to pay attention to the substrate and decorations so you can create a natural habitat for your Common Pleco. These bottom-dweller species are shy and prefer to have lots of hiding places when needed. 

Developing hiding places in your aquarium is as easy. When you add lots of driftwoods and rocks to decorate your tank, you can create hollow spaces so your fish can hide. In order to provide the fish with a safe environment, you will need to place pleco caves so they can rest throughout the day. You can make DIY caves out of driftwood, or PVC pipes or purchase commercially made pleco caves. Commercially constructed pleco caves are the best option because they are specifically created for the needs of this species.

L021 has a very soft belly, this means it will need a soft and fine substrate. In the wild, the river they come from has a fine sandy and muddy substrate. This means you will need to recreate the same or similar setting for your tank. In an aquarium, sand is the closest substrate to this fish’s natural habitat. However, if you grow aquatic plants as well, then many planted substrates are also great options. 

Plants are a vital part of any balanced ecosystem. Aquatic plants will remove toxins from your tank while providing plenty of hiding spots for your fish. You can use floating plants or any other aquarium plants to add beauty and functionality to your aquarium.  

Water Parameters:

Common Pleco are very manageable when it comes to water parameters they need. They are as hardy as other species in their family and will live in similar tropical parameters as most fish coming from South America. These parameters are easy to maintain even by beginner aquarists. Below are the tank parameters you can keep this species in: 

  • Temperature: 70 – 80 Degrees Fahrenheit 
  • PH: 6 – 7.5
  • TDS: 100 – 200 PPM

A Total Dissolved Solids (TDS) meter is a must-have for any pleco keeper. The TDS meter can measure the concentration of dissolved substances in your aquarium. If the TDS in your tank rises beyond the recommended level, you should perform a water change. We think that TDS and heat are the main parameters that even novice fish keepers should track. However other parameters like pH, GH, and KH are also crucial to track if you have to test kit to check.


Keep in mind that Common Pleco prefers diffused light, so if you don’t have any plants, you should keep the aquarium lights dim. To ensure that your plecostomus has somewhere to hide while the aquarium lights are on, simply add more decorations or caves. 

If you have live plants, pick your lights according to the plants you keep. Your plecos will stay at their favorite hiding spot when the lights are on.

Filter System:

We strongly recommend getting the largest filter you can afford. This is because Common Plecos produce a considerable amount of waste so a large filter is a must-have to manage waste and prevent ammonia spikes in the aquarium.

Common Diseases and Prevention

When tank parameters are not in favor of Common Pleco, they tend to get ill. Long periods of stress, low water quality, and bad diet are among some of the reasons your fish can get diseases. They are also vulnerable to all common aquarium diseases that any new fish might bring into your tank.

Ich and internal worms are among the most common diseases these fish can get. If you notice your fish have any of these diseases you will first have to check what caused the issue and eliminate it. There are medications sold in pet stores that will cure these diseases. You should follow the instructions on the packaging before treating your tank. It is always best to ask for help from other experienced fish keepers or vets to diagnose the disease correctly and treat it accordingly.

Never introduce new fish or plants to your tank without first adequately quarantining them to ensure they won’t spread any diseases to your tank. By doing so, you will significantly lower the possibility of tank epidemics that might occur in your aquarium. It is also crucial that you maintain a clean tank that gets regular water changes. Food leftovers in the tank can lead to bacterial illnesses and even internal or external worms. So it is important not to overfeed your aquarium.

Diet and Feeding Requirements

The main misconception we see online is that Common Pleco can survive on algae and vegetables alone. While they will happily eat algae and plant matter, these fish also need meaty foods in their diet. You will need to provide them a good mix of different foods so they can get all the nutrition they need. 

Dry foods like sinking pellets, shrimp wafers, algae wafers, and other available fish foods are the ideal diet to feed your common pleco daily. Some brands of these fish foods are very high quality while some might not have all the ingredients your fish needs. That why, you must buy a few different types of sinking foods (mainly plant based) and feed your Common Pleco. 

Plant based sinking pallets should be the primary source of nutrition for your this species of aquarium fish. Live or frozen foods can make great snacks that can be given once or twice per week in low amounts. Make sure your fish have a wide variety of foods available so they can get all the nutrients they need. Because the these fish are primarily active at night, it is better to feed them overnight.

Common Plecos are omnivores and thrive on a mixed diet of fresh vegetables and protein-rich foods. You can feed them fresh vegetables like: zucchini, cucumber, green or red pepper, potatoes, and spinach.

There are many protein foods available that you can feed your pleco. Live or frozen foods like brine shrimp, bloodworms, and tubifex worms can be great protein sources. Some specimens will also eat small and newly hatched snails that might be in your tank but this is not a common behavior.

Breeding Common Pleco

Breeding Common Pleco in the aquarium is probably not possible as there are not many reports breeding them successfully in captivity. They need a natural environment to be able to breed. Recreating these natural events is not an easy task thus not many people attempt to breed this species. The other reason is that these fish are widely available in nature so it is more affordable to collect them from the wild than to breed them.

We know that this species is a cave breeder but the kind of cave they like to breed in is not known yet.

Tank Mates

Despite the fact that Common Pleco are generally calm and friendly fish, when they are at their breeding season, male specimens may become territorial. Having said that, if you decorate the aquarium correctly, this fish will not display any aggressive behaviors and can peacefully live with any fish.

Selecting Tank Mates for common pleco is very easy, most South American fish can happily live with this species. However, you will need to make sure all your fish can live in the same water parameters.

Here are some good tank mates worth considering: 


Now that you are knowledgeable about the essentials of Common Pleco care, you are prepared to confidently look after your pleco pet. These fish are relatively quiet and won’t bother any other individuals in the aquarium. They will do best in warmer water that is well-oxygenated and clean.