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Plecostomus Care Guide: Feeding, Breeding, and More

Plecos are probably in the top 10 as far as aquarium fish popularity and being easily recognizable. They go by several common names, including Suckermouth Catfish and generic “Algae Eaters.” The Common Plecostomus is all of these things – and much more besides! Let’s take a closer look at this iconic aquarium fish!

Getting to Know the Common Plecostomus

Getting to Know the Common Plecostomus

Plecos of all kinds are found in South America, especially within the Amazon and Orinoco River basins. In this equatorial rainforest region the temperatures stay elevated all year round and occasional flooding allows plecos to find plenty of algae, driftwood, and detritus in the forests that periodically get overwhelmed by rising waters.

Most Common Plecos are captive bred nowadays in massive farms in East Asia. However they remain hard, popular additions to aquariums thanks to their ravenous appetites for algae and leftover food. Still, they should not be as popular as they are. Plecos are quite large once fully grown and unfortunately become both territorial and aggressive as they mature.

Are Common Plecos right for you? Find out in this extensive plecostomus care guide!

  • Scientific Name: Hypostomus plecostomus
  • Origin: South America
  • Length: 12-15 inches
  • Aquarium Size: 55+ gallons 
  • Temperament: Peaceful to Semi-aggressive
  • Ease of Care: Very Easy

Types of Plecostomus

Believe it or not there are quite a few different kinds of plecostomus out there! This guide will be focusing on the Common Pleco, the most popular species of them all. But it’s worth introducing some of their close cousins!

Sailfin Pleco

Sailfin Pleco

The Sailfin Pleco (Pterygoplichthys gibbiceps) is an impressively large type of pleco, reaching anywhere from 15-20 inches long when fully grown. They get their name from their expansive dorsal fin, which only grows larger with age.

Sailfin Plecos are so large that they are really only suitable for aquarists with tanks 100 gallons or more in volume. They eat tremendous amounts of algae – so much so that you’ll need to offer supplemental food since no tank can grow enough to keep them fed.

Clown Pleco

Clown Pleco

On the other end of the size spectrum is the Clown Pleco! Also known as Panaque maccus, these little guys max out at 3-4 inches, making them perfect even for aquariums as small as 10 gallons! Clown Plecos get their name from their mottled stripes and are one of the more beautiful species of plecostomus.

Zebra Pleco

Zebra Pleco
found on reddit

The Zebra Pleco is the Holy Grail for many a pleco keeper! They are some of the most beautiful freshwater aquarium fish in the hobby – and unfortunately much more challenging to keep than the other species mentioned here. For starters, Zebra Plecos are mostly carnivorous, feeding on invertebrates and other meaty food. They also need fast moving, highly oxygenated water to do well.

Caring for Common Plecos

Plecostomus Water Conditions

Plecostomus
found on reddit

Common Plecos are some of the hardiest fish you’ll come across, especially the captive bred ones usually found in the hobby. In the rainforest conditions they are native to, plecos are found in water with a low concentration of dissolved minerals (soft water with a low GH/KH). These same waters are full of plant tannins, which increases the acidity (pH <7.0). In fact, plecos are popular additions to blackwater aquariums, where the tea-colored plant tannins can bring the pH as low as 4.5.

That said, plecos are hardy enough to not require soft, acidic conditions to do well. In fact, they even do just fine in hard, alkaline water alongside African Rift Lake cichlids and other fish. But if you can provide it, even captive bred plecos do a little better in the acidity they are native to.

Plecos are also tolerant of higher than normal levels of ammonia, nitrite, nitrate, and other nitrogenous waste products. Since they are so durable, aquarists often add plecos to the tank first to help initiate the cycling process. Fishless cycling is safer for your fish and just as effective but the chemistry required may be too challenging for new aquarists.

You should never subject your plecos to dirty water conditions though, just because you can. Make sure you’re regularly performing water changes to siphon out feces and nitrates, which aren’t broken down by nitrifying bacteria and need to be removed from the tank in other ways.

Plecos prefer elevated tropical temperatures of around 75-85℉, similar to Discus, Angelfish, and other Amazonian natives. But they are tough enough to even survive room temperature conditions. I don’t recommend keeping plecos in a coldwater aquarium since their immunity goes down greatly in cool conditions. Plecos are much more susceptible to ich, body fungus, bacterial infections, and other diseases if they get too cold.

Aquascaping for Plecostomus

Plecostomus Aquascaping

You’ll want to think carefully on aquascaping when keeping a Common Plecostomus. Live plants can be a good match for a young 1-2 inch baby pleco as they will benefit from having their leaves scrubbed free of algae and biofilm daily. 

But as they grow older, plecos can become increasingly rough on softer plants. In fact they may simply eat soft leaved plants like Cabomba and Elodea. Tough, bitter plants like Java Fern and Anubias can stand the attention of an adult plecostomus but not much else. If you start seeing fresh holes appearing in your plant leaves it’s likely your pleco isn’t getting enough greens in their diet.

An adult plecostomus may even unintentionally knock over rooted plants in a small tank. Remember, these fish can top a foot in length easily and are fast and powerful. When turning on the tank lights abruptly at the start of the day plecos sometimes have the habit of dashing about in fright, which can result in decorations being torn free.

One of the best things to place in any pleco aquarium is driftwood because it offers a whole host of benefits! For starters it is a slow and steady source of the plant tannins that help buffer your aquarium water towards acidity. Driftwood also provides a perfect growing surface for bacteria and algae, which form a thin film that your pleco will continually graze upon.

Some species of pleco actually eat waterlogged driftwood, especially Bristlenose Plecos. Common Plecostomus may eat small amounts but they don’t need it as a digestive aid as other species do.

Lastly, driftwood provides your pleco with a secure place to hide. Notice how nicely a Common Pleco’s mottled color helps them camouflage themselves within the shadowy nooks driftwood offers. This is their natural habitat.

Feeding Common Plecos

Feeding common plecos
found on Flickr

Feeding a Common Plecos is a very easy affair! They are vegetarian for the most part but will also sample meaty items. Any leftover fish flakes will be vacuumed up by them with relish!

Plecos are excellent algae eaters as well. They aren’t as good as some of the other kinds of algae eaters out there since they have a strong preference for green algae. Brown algae, blue-green algae, staghorn algae, and other kinds are likely to be ignored by them. But they are voracious eaters of all green algae types!

This aside, you should never rely on your pleco eating solely algae and leftover food or they will grow skinnier and skinnier until they starve to death. Plecos need feeding as well. Most pet stores carry prepared sinking pellet and tablet blends enriched by spirulina and plant matter. 

You can also offer blanched spinach, zucchini, peas, and other terrestrial vegetables to your fish. Simply clip it near the bottom and leave it overnight, you’ll see holes chewed in the veggies by the next morning! Be sure to remove it at this point since vegetables can easily rot, contributing to cloudy water and rising ammonia levels.

An unfortunate myth that’s been around for decades and continues to be repeated is that many types of plecos eat fish poop. Nothing could be further from the truth; plecos do not eat fish poop of any kind. 

In fact, they make plenty of their own – bening vegetarians all that roughage has to go somewhere! They tend to leave long drapes of poop on plants and driftwood that may need occasional tidying up between water changes, unfortunately. Any poop from your other fish will need to be cleaned up in the usual way.

Tank Mates for Plecos

Tank mates for Plecos
found on reddit

When young, Common Plecos are small, peaceful, and cute community tank dwellers that can fit into just about any setup! But as they grow larger they can grow increasingly aggressive and intolerant. They aren’t dangerous to most fish but you will need to plan carefully for this tendency.

Plecos can be troublesome towards slow moving fish with broad flanks, including Goldfish, Discus, and Gouramis. Occasionally a pleco will latch onto a tank mate, especially sleeping ones, to rasp a bit of nutritious mucus from their sides. This isn’t too common but be watchful because losing mucus on their skin makes it easier for parasites to attack fish.

On the other hand, it’s very common for adult plecostomus to become territorial and aggressive. They will usually choose a hiding place and act pushy towards other fish that try to investigate it too closely. While they don’t have the teeth to do actual damage they may cause more peaceful tank mates stress, especially in a smaller tank.

Plecos will fight most often with each other, especially over choice hiding places. So keeping more than one is a bad idea unless the tank is spacious enough for them both to claim separate hiding places. Even then, your plecos will occasionally run into each other and spar, using their tails like battering rams and flaring their fins at each other until one surrenders.

Lastly, Common Plecos are excellent companions for large, aggressive fish like Oscars, Arowanas, and other predators. Their armored flanks and bony fin spines allow them to stand strong against occasional squabbles. A pleco may even out-last other territorial fish, simply shoving them away until their tank mate gives up!

Good Tank Mates for Plecostomus:

  • Tetras, Livebearers, Barbs, Gouramis, and other Community fish 
  • Large Cichlids, Pacus, Arowanas, and other large, Predatory Fish
  • Corydoras, Loaches, and other peaceful Bottom Dwellers

Poor Tank Mates for Plecostomus:

  • Discus, Goldfish, and other slow-moving, deep-bodied fish
  • Other Plecostomus

Breeding Plecos

Breeding Plecos
found on Flickr

Unfortunately breeding Common Plecostomus is almost impossible to do in home aquariums. The fish aren’t ready to produce eggs and sperm until they are fairly large; 12 inches or more. Plus they are highly territorial and will chase away any other plecos unless both are ready to mate.

In the wild, male Common Plecos will dig holes in the mud along the Amazonian river where they try to coax females into entering and depositing her eggs. The male will then guard the eggs until they hatch within 48-72 hours. The young fry absorb their yolk sacs within 48 hours and quickly leave to fend for themselves, hunting for algae and biofilm to graze on. 

Breeding Common Plecos is much more commonly achieved in massive breeding ponds in Southeast Asia, South America, and other tropical countries where they can be kept outdoors year-round. In these huge ponds plecos can grow to their full adult size and graze on unlimited amounts of algae, producing loads of young for the aquarium trade in the process!

FAQ About Plecos

How Big do Plecos Get?

Most types of pleco are on the smaller end of the spectrum but Common Plecos regularly grow anywhere from 12-15 inches, making them one of the larger species!

What Size Tank Do Plecos Need?

A baby pleco can live in a 10 to 20 gallon aquarium with ease. But as they grow up, you’ll need to continually upgrade their aquarium. 55 gallons is an absolute minimum for an adult plecostomus, with 75 gallons or more being much more comfortable.

How Many Plecos Should Be Kept Together?

You should only keep one Common Pleco per aquarium unless you have a tank that’s 100 gallons or more in size. Plecos of most kinds are very territorial and will fight for the best hiding and grazing places. A pleco continually left exposed by their rival will become stressed by the lack of cover.

Can Plecos Eat Fish Poop?

Definitely not! Plecos are mostly vegetarian, feeding on algae, leftover fish food, and soft plant matter. They also eat continually, so supplement their algae grazing with boiled vegetables and sinking algae wafers!

Jason Roberts
About Jason Roberts
Jason is an aquarium fanatic that has been a fish hobbyist for almost three decades.

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