Common Plecos are a very popular freshwater fish that have been kept in the aquarium community for ages. They’re hardy, straightforward to care for, and very fun to observe.

But despite the popularity of this fish, there’s actually a lot of inaccurate information passed around about them online. This results in newer aquarists making mistakes and providing poor care without knowing it!

This guide will cover the essentials of Common Pleco care. You’ll learn about their diet, ideal tank size, tank mates, lifespan, size, and more!

Species Summary

Lovingly referred to as a “Sucker Fish” in many circles, the Common Pleco (scientific name: Hypostomus plecostomus) is a freshwater aquarium staple! These fish have been in the trade for decades and continue to captivate fish enthusiasts.

Hypostomus plecostomus resting on the substrate

The Common Pleco belongs to the Loricariidae family, which is a large group of armored catfish species. Originally, this species comes from South America. Specifically, they are abundant in countries like Brazil, the Guianas, and Trinidad and Tobago.

Author Note: Common Plecos have started to appear in several countries around the world, too. Due to pet owners releasing these fish into the wild, they’re considered an invasive species in many regions.

There are many misconceptions about this fish. If you’re thinking about owning a Common Pleco, it’s important to get a good understanding of what caring for this fish entails.

Common Pleco Lifespan

In pristine conditions, the typical Common Pleco lifespan is between 10 and 15 years! They have a longer life expectancy than most tropical fish, so be prepared for years of care.

As always, there’s no guarantee with any fish species when it comes to lifespan. The quality of care you provide will impact the fish’s overall health for better or worse.

Appearance

Common Plecos have a signature shape that you might have seen before. Like catfish, all types of plecos have an underturned mouth, flat belly, and expansive fins.

When it comes to coloration, Common Plecos are pretty simple. They have a base color of brown. Several small black splotches cover the entire body, creating a unique net-like effect.

Author Note: Other color variations do exist. You might see some Plecos that are lighter or those that have sand-colored spots. The coloration of this fish varies based on the environment they come from.

On top of their body, these fish have a unique physical characteristic. They have several rows of armor plates! These plates are tough and offer loads of protection from predators.

These fish are bottom-dwellers, so that added protection from above is essential. On their bellies, Common Plecos don’t have armor at all.

A Common Pleco swimming with other fish in a freshwater aquarium

Like other fish in the Loricariidae family, Common Plecos have impressive fins. The dorsal fin is expansive and has several rigid fins. The same goes for the tail, pectoral, and pelvic fins.

On the head, Common Plecos have small beady eyes. These fish are nocturnal, so the eyes are equipped with tissue that regulates the amount of light getting in. On the bottom of the head, you’ll find that iconic sucker mouth!

Average Common Pleco Size

The average Common Pleco size in captivity is around 15 inches in length when fully grown. They’re known to have a max size as large as 24 inches in the wild!

Some specimens living in massive environments can reach similar lengths in captivity, although this is pretty rare.

When you first buy a Common Pleco, it’ll likely be a few inches in length at most. But don’t let that small size fool you! As we’ve said, these fish can get huge and have a pretty steady growth rate.

Care

Proper Common Pleco care isn’t a huge challenge. These fish adapt well to a wide range of environments. Plus, they have healthy appetites for pretty much any food they can find!

That said, keeping a Common Pleco healthy isn’t as easy as some people think. They have distinct care requirements and some behavioral quirks you need to address.

Here are some care tips you can follow to keep your Common Pleco happy and healthy.

Tank Size

Adult Common Plecos need a tank size of 75 to 80 gallons at the very minimum. However, to help your fish reach its full size and potential you’ll need at least 150 gallons!

Larger is always better with the Common Pleco.

If you plan on starting small, these fish do well in tanks that can hold up to 30 gallons when they’re juveniles. 

Author Note: Tank size is where many beginning fishkeepers go wrong with the Common Pleco.

Because these fish are usually sold as juveniles, some people think that they’ll do fine with a smaller tank. Those smaller tanks are fine as the fish grows, but you’re going to have to move them to a much larger aquarium at some point.

Water Parameters

Common Plecos do best in environments that replicate their natural habitat in the wild. This includes both decor (more on that in the section below) and water conditions!

These freshwater fish come from slow-moving tropical rivers. The waters are warm and highly oxygenated. Here are some basic parameters to stick to when setting up your fish’s new home.

  • Water temperature: Between 72°F and 86°F (somewhere in the middle of this range is ideal)
  • pH level: Neutral pH balance between 6.5 and 7.5
  • Water hardness: Up to 25 dGH

Stick to a consistent schedule when it comes to testing the water (once a week should be fine). It’s very important to make sure the parameters and general conditions are stable.

Setting Up The Rest Of Their Tank

To replicate the Common Pleco’s natural environment, go with traditional riverbed decorations. These fish will spend most of their time at the bottom of the tank, so spend some time getting the decorations just right.

Use a fine sand substrate at the bottom. Common Plecos do fine with gravel, but sand is softer and less likely to cause injury.

On top of the sand, arrange live plants. The plants will act as a shelter from the light. Next, add some natural caves and driftwood.

One Common Pleco with a smaller tank mate

Caves are essential for this nocturnal fish. They’ll hide out in the shadows to get some rest during the day. A cave will block out light while keeping the fish protected from any other nosy fish in the tank.

Driftwood is important, too. These fish like to munch on driftwood for a source of fiber. It’ll also grow algae, which is another important food for the Common Pleco.

Keep lighting relatively subdued. At night, the tank should be dark. Utilize a red light to view the fish after hours.

As for filtration, go with the most powerful option you can find (our recommendation would be the Fluval FX4). Common Plecos produce a lot of waste. They’re constantly eating, which can sour the water quality pretty quickly.

Author Note: Many Pleco owners prefer to over-filter the water. This means that they have a filtration system that’s more powerful than what their tank would normally need. With the large size of the Pleco, that extra power can do a lot to keep ammonia and nitrate levels in check.

Common Potential Diseases

Plecos can suffer from all of the same diseases as other freshwater fish. Many believe that Plecos are more sensitive to disease. While they have large plates of armor, these fish don’t have small scales to protect their body from contaminants and bacteria.

Some common diseases you might encounter are ich and dropsy. Ich is a common ailment that’s usually caused by stress. It’s very contagious and causes small white bumps to form all over the fish’s body.

Dropsy is a form of bloat. The fish’s body starts to swell up with fluids, making it difficult to swim.

Your fish may also experience bacterial or fungal infections. These maladies tend to accompany other diseases.

Fortunately, all of these issues are very preventable.

They’re usually caused by poor water conditions. Use a test kit to check conditions regularly. You should also perform 30-percent water changes every week to support the filtration system.

If your fish contracts a disease, quarantine them to start treatment immediately. Use a Pleco-approved medication or utilize natural treatment methods to cure your fish. Common Plecos can be sensitive to copper-based medicines, so exercise caution.

Food & Diet

Many pets stores market Common Plecos as some of the best algae eaters. And it’s true that they will consume algae every once in a while.

However, it shouldn’t be their diet staple.

Common Plecos are omnivores with a big appetite. They will constantly scavenge the tank for food to eat. These fish will consume anything they can get their mouths on, so you shouldn’t have trouble getting them to eat!

The mouth of a Common Pleco

A varied diet of vegetables and protein-based foods is ideal. You can supply blanched lettuce, zucchini, peas, and more for vitamins and nutrients.

For protein, consider live or frozen snacks. This can include bloodworms, small crustaceans, fly larvae, and earthworms.

Author Note: You can also provide sinking dry food. Common Plecos enjoy balanced pellet food and algae wafers.

Behavior & Temperament

When they are young, Common Plecos are pretty easy-going. They get along well with most fish of a similar size.

However, that changes once they reach adulthood. These fish can exhibit aggressive behavior when they are fully grown.

This is primarily because they can become territorial. This behavior applies to even fish of the same species!

In general, Common Plecos prefer to stay alone and will have no problem attacking other fish. They seem to target brightly colored fish with flowing fins, such as Angels and Discus.

Don’t expect to see much activity during the day. This species will spend their days in hiding as they rest.

After the sun goes down, these fish will go into scavenging mode! They’ll use their sucker mouths to cling onto glass, eat algae, and chow down on driftwood. Plecos are constantly eating, so it’s never a dull moment when they’re awake.

Tank Mates

Because of their territorial behavior, you can actually keep Common Plecos with other semi-aggressive fish. This might seem dangerous, but it’s actually beneficial for every fish involved.

Common Plecos are tough enough to stay safe. Their armored bodies can protect them from nips and bites. Usually, semi-aggressive fish develop mutual respect for each other and learn to coexist.

Your best bet would be to choose similarly sized fish that occupy other parts of the water column. However, smaller peaceful fish that spend their time near the top of the aquarium can work too. Common Plecos are bottom dwellers, so they won’t bump into fish that stay in the middle and upper parts of the tank.

Here are some good tank mates to try:

Breeding

Breeding Common Plecos in captivity is extremely difficult, and there are a couple of reasons for this.

First, you would need a massive tank. Two adult Common Plecos need around 300 gallons of space to stay healthy!

Secondly, the territorial nature of this species makes it tough. Most fish will just fight to the death rather than spawn.

Breeding is much easier if you’re able to raise Common Plecos together as a bonded pair. If you’re lucky enough to get your hands on a pair, the breeding process is straightforward.

Males will find a suitable cave for spawning. He’ll then clean the cave and invite the female. She will then lay her eggs on the side of the cave. Males watch over the eggs until they hatch, which takes a few days.

Generally, breeding Common Plecos is reserved for professionals with massive breeding tanks. Don’t expect to see much success if you try to breed the fish at home.             

Conclusion

If you’re looking for a large but low-maintenance freshwater fish, the Common Pleco is a great choice. There’s a reason this species has been popular for so long!

There’s something about their size and simplicity that’s really fun to watch. Seeing this large aquatic creature move around the tank is rather mesmerizing.

If you have any lingering questions about Common Pleco care we would be more than happy to chat with you. Simply shoot us an email and we’ll reach out as soon as we can!

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