Plecostomus Complete Guide: Species, Care, Tank Requirements…

Plecostomus, or Plecos, are a group of armored catfish that belong to the Loricariidae family.

They are by far the most popular catfish amongst fish keepers and in total there are well over 150 species.

The most in demand member of this family is called the Common Pleco and can grow up to 24 inches long.

In our complete guide, we discuss the various species, care guide, tank mates, aquarium requirements and much more.

Want Something Extra? Download your free Plecostomus guide to learn all about their dietary needs, tank conditions and more.

Category Rating
Care Level: Medium
Temperament: Peaceful
Color Form: Brown, Gray
Lifespan: 10-15 Years
Size: Up to 24″
Diet: Omnivore
Family: Loricariidae
Minimum Tank Size: 30 Gallons+
Tank Set-Up: Freshwater: Driftwood and Caves
Compatibility: Limited due to size constraints

Plecostomus Overview

The Plecostomus catfish, or Pleco for short, is a name used for the catfishes that belong to Loricariidae family.

In total there are more than 150 different species; ranging from small to large and peaceful to aggressive catfish. You may have heard of the naming system (“L” or “LDA” followed by numbers) which is used to identify the various members of the Loricariidae family.

Whilst lots of beginner fish keepers think that the common Pleco refers to the Loricariidae family it actually refers to a specific member of the family; the Hypostomus plecostomus.

The common Pleco is the most popular freshwater catfish amongst fish keeping enthusiasts and is a type of armored catfish. It is found in the freshwater streams and rivers of South America, can grow up to 24 inches in length and have a lifespan of 10-15 years.

Pleco

Typical Behavior

The first thing to know about this fish is that it is nocturnal. This means during the daytime you won’t see much activity. In the daytime, they can appear timid and you will likely find them hiding amongst the plants and any caves inside your tank.

When they are active you will notice that they are a bottom dwelling fish and will move slowly across the floor of the aquarium. Whilst moving slowly across the floor they make a superb job of cleaning up algae within the tank.

It’s important to note here that while they will eat algae, their diet should not be made up of that alone. Many pet stores advertise them as algae eaters which is dangerous as they are omnivores and require other nutrition.

You will also notice here that they use their suckermouth and attach themselves to the glass or rocks within the aquarium.

Whilst they generally have a friendly temperament they do best in a tank on their own due to size constraints (read the tank mates section below for more).

Appearance of Plecostomus

Plecostomus OverviewThe majority of Plecos are brown in color; however certain species’ coloration is dependent on their environment. The majority of them also have sand colored spots or patterns.

They are referred to as “armored catfishes” because they have large boney plates that cover their body.

One of the most unique things about them is their mouthparts; this is what makes them so effective at cleaning algae.

As for their appearance; in the wild they will grow to around 24 inches in length, in an aquarium this will only grow to around 15 inches.

Like other members of the family, they have an elongated body which covered with four rows of bone plates. The bone plates are not present on their abdomen. They have well developed dorsal, pectoral and tail fins. The dorsal fin has one coarse ray and seven soft rays. The anal fin has one coarse ray and between 3-5 soft rays.

Its body is gray colored with brown spots and patterning.They have a large head with small eyes that are high up on their head. Interestingly they have a membrane covering their eyes which allows them to control the light exposure into their eyes.

One of the most interesting things about this fish is its tail fin; it is moon shaped, the bottom part being longer than the top.

Plecostomus Types (Species)

To date more than 150 different species of Plecos have been discovered, however not all of them should be kept in aquarium. Below is a list of the most popular aquarium ones:

  • Bristlenose Plecostomus (Ancistrus sp.)
  • Gold Nugget Plecostomus (Baryancistrus sp.)
  • Zebra Plecostomus (Hypancistrus zebra)
  • Clown Plecostomus (Panaqolus maccus)
  • Sailfin Plecostomus (Pterygoplichthys gibbiceps)
  • Snowball Pleco (Hypancistrus inspector)
  • Royal Plecostomus (Panaque nigrolineatus)

Plecostomus Size

In the wild a common Pleco will grow to around 24 inches, and in an aquarium it will typically grow to around 15 inches.

Plecostomus Habitat and Tank Requirements

Bristlenose Pleco
A Bristlenose Pleco

The majority of Plecostomus are native to South America. They can survive in a wide range of habitats, with the majority of them living in fast flowing streams and rivers with a rocky substrate. However some can be found in brackish estuaries.

You should remember though that each species is unique and no two require the exact same habitat or tank setup. So you should thoroughly research the needs of the specific breed you’re interested in keeping.

An example of this being aquarium sizes. Smaller Plecos (Otocinclus Catfish) can survive in a 10 gallon tank whereas larger species such as a Bristlenose needs a minimum of 25 gallons.

Now let’s look at the common Pleco and their specific requirements.

It’s important to note here, that they are usually only 2-4 inches long when first bought, grow very large, very quickly. Therefore they are only suitable for more advanced aquarists in tanks of at least 80 gallons. As it grows, you’ll need at least a 150 gallon tank.

The Hypostomus plecostomusis native to the tropical waters of South America, specifically the Amazon River basin.

This natural environment consists of shallow streams and rivers that flow through tropical forests.

This water tends to be fast moving and littered with driftwood and plants; you will find them hiding amongst them during the daytime.

So how does this translate in setting up an aquarium for Plecos?

Firstly, you should make sure that their aquarium has plenty of hiding places as they will sleep in these places during the daytime. You can create these hiding places by adding caves and hollowed logs. You can also use upturned flower pots.

They also prefer a tank that is heavily planted. You should make sure these plants are hardy because they like to nibble on them. Faster growing plants such as java moss is ideal. As mentioned in the dietary need section (below) you should also make sure they always have access to driftwood to nibble on.

This combination of dense debris and vegetation helps to make them feel safe and secure.

Tank Conditions

As previously mentioned they are fairly hardy fish so the water parameters aren’t as critical to maintain when compared to other fish.

The most important thing is maintaining a strong water current and keeping it well filtered. For this you should use good quality canister filters.

As for the parameters you should aim to keep the water temperature between 72°F and 86°F, with pH levels between 6.5-7.5.

The most important aspect of the water conditions is just to ensure you keep your water clean.

What Size Tank Do Plecostomus Need?

The common Pleco, it requires a huge tank. Once they reach an adult they need at least a 150 gallon tank.

As for other popular species here are their minimum tank sizes:

  • Bristlenose Plecostomus (Ancistrus sp.): 25 gallons
  • Gold Nugget Plecostomus (Baryancistrus sp.): 50 gallons
  • Zebra Plecostomus (Hypancistrus zebra): 30 gallons
  • Clown Plecostomus (Panaqolus maccus): 30 gallons
  • Sailfin Plecostomus (Pterygoplichthys gibbiceps): 125 gallons
  • Snowball Pleco (Hypancistrus inspector): 30 gallons
  • Royal Plecostomus (Panaque nigrolineatus): 125 gallons

Plecostomus Diet and Feeding

As you already known most are sold as ‘algae eaters’ which would have you believe that they are herbivorous; however most of them are carnivorous and will eat smaller fish, invertebrates and crustaceans. Whilst they won’t outright kill for meat they will scavenge making them ‘opportunistic’ omnivores.

Certain varieties also feed on wood, so make sure you thoroughly research the exact species you are interested in to ensure you meet their dietary requirements.

As for the Common Pleco, the common misconception is that they can live purely on algae. This is wrong and in fact leads to malnourished fish that are unhealthy.

Their diet should be comprised of vegetables and algae; they will occasionally eat meat/live food.

Like always, we recommend that a high quality pellet forms the basis of their diet.

For vegetables you can feed them: lettuce, zucchini, spinach, shelled peas and cucumbers to name only a few of their favorite.

For live foods: bloodworms, earthworms, crustaceans and larvae. Our preference is the worms because they sink, meaning in a community tank the Plecos can still eat.

One important point to remember is that they require lots of fiber; feeding them a lot of vegetables helps them meet this requirement. You should also make sure they always have access to driftwood to help with their digestion.

As for feeding habits, if you’ve read the typical behavior section above you will know that they are nocturnal. So you will find they eat best during the evening just before you turn the lights in the tank off.

Common Pleco

Plecostomus Tank Mates

The first thing to bear in mind is that this fish is nocturnal.

As a youngster this fish is fairly peaceful and can be kept in a community tank. Some ideal tank mates include:

  • Cichlids
  • Tetras
  • Gouramies
  • And other common community fish

Even as juveniles you should avoid placing it with Discus and Angelfish as they are known to nip at them. Bear in mind the usual rule – any smaller tank mates shouldn’t be able to fit in the Plecos mouth; if it can it won’t be long until its tank mate turns into dinner.

As it ages it will quickly outgrow other fish and should be kept in its own tank.

Can You Keep Plecostomus Together?

Whilst in theory you can keep them together, in practice it is near impossible due to the size constraints.

If you want to keep two or more together you would need at least a 300 gallon tank making this unreasonable for all but the most experienced fish keeper.

Breeding Plecostomus

Unfortunately not much is known about breeding Plecostomus, and even less is known about breeding them in an aquarium.

What is known is that it is very difficult to breed them in captivity.

They are egg-layers and in the wild they generally spawn in caves, laying large volumes of eggs on flat surfaces.

The male will then guard the cave until the eggs have hatched. As fry they are known for being demanding eaters requiring large amounts of protein.

Is the Plecostomus Right For Your Aquarium? (Summary)

After reading this complete guide you should know if the common Pleco is right for you and your aquarium.

If you’re interested in other members of the Loricariidae family, we have already published the Bristlenose Pleco guide and are currently authoring more.

Whilst in principle they are easy to keep and don’t have any complex care needs, due to the size of aquarium they need, it makes then unsuitable for all but the most experienced fish keepers.

This makes them a large commitment, so make sure it’s the fish for you before you decide to get one.

Let us know in the comments section below if you keep any Plecos…

Robert Woods Portrait
Robert Woods is the creator of FishKeeping World, a third generation fish keeper and a graduate in animal welfare and behavior. He is also a proud member of the Association of Zoos and Aquariums, the Marine Aquarium Societies of North America and the Nature Conservancy.

26 Comments

  1. Hello. We have had an aquarium for, it seems, forever. Our son started it when he was a teenager, is 42 now. Anyway, we have grandchildren now who loved the aquarium when they were small and are now teens as well though don’t come around as often anymore or pay attention to the aquarium. I have taken over the duty of caring for these fishies, which I love doing btw. However, it has been a chore and worry for a while because there were two goldfish which grew to be about 10 inches and about an 8 inch. Also two Cory catfish, three hatchet fish and a pleco, very small at the time. I decided to bring the goldfish to a pond, which was sad because they were like pets, owned by a friend and they are thriving, thank goodness. Now the pleco has grown to be enormous, about 10 inches long. I read that it needs, at least, a 125 gallon n tank, but our is a 30 gallon tank. I can not have a larger tank though… the pleco seems to be doing very well though. Will it be all right to keep it. I would hate to get rid of it, he’s used to me now, I can tell when feeding time comes around.

    • Hello Wilhelmina,
      It’s nice that so many of your family have been able to enjoy the aquarium. As we mention in the article, these fish are all too often sold to customers with smaller tanks. I always recommend opting for the minimum size tank for a species.
      Robert

      • Thank you, Robert. The sad thing about the pleco is that he/she can not be put into a pond like the goldfish, which are cold water fish. I’ll make sure to take good care of him/her. He/she has a beautiful, large cave and plants. The two Cories have their own small cave and the 3 small hatchet fish swim at the top. All seem to be happy…so far.

  2. I have a 70 gallon upright cylinder aquarium, and am the proud owner of a beautiful leopard sailfin pleco. I am realizing though that the gallon size does not really matter as much as the dimensions of your aquarium. With an upright cylinder shaped aquarium, you are really limited by the amount of floor space you have. (24” diameter). So, I am facing the realization that I will need to be rehoming my beautiful fish sometime in the near future as it is about 8” now. I am considering another aquarium, but am also considering a stock tank. But the bottom line is… a lot of pet shops and pet owners really only discuss aquariums in gallons when they should also discuss sq feet. Not all 70, 100, 125 gallon aquariums are created equal and provide the optimal living space for such large fish.

    • You’re very right! It’s a sad truth that unfortunately, many staff who work in pet stores are just not properly trained. I’m glad you had the foresight to research for yourself and make the best decision for your sailfin pleco! Robert

  3. I purchased our Pleco named “PLuTO” from Wal-Mart nearly 3 years ago, as a pet for my young son.
    Since our living space is limited, 1 gallon classic fishbowl was seemingly a good choice;) Although I purchased algae wafers, fresh spinach, couple of peas & cucumber, but our pleco (Aka. PluTo) refuses to eat those this food. PluTo diet consists Tetra Goldfish flakes 2x per day, ever since the 1st day I brought him home. 😊 I also, purchased dried shirmp food,to add some pritein, but suddenly it turned a completely different color (strange light tan color) and so I haven’t fed it shrimp eVer agAin; within a few hours, the condtion reverted & it was back to looking “normal” again.
    [As for it’s living environment…] I replace the “tap-filtered” water/& clean the glass bowl about once a week; rinsing everything with hot water + a small amount of white vinegar. That’s it.

    Our pleco seems “Happy”, never been sick and has out-lived 5 goldfish & a Chinese Mystery Snail, amazingly!
    My only worry has been, if it’s getting enough food each day, because it hasn’t grown at all… I feed it couple times per day (morning when I wake/& the same at night, before I go to sleep). It never seems ravenous, but nevertheless it’s remained the same size ever since the day I brought it home.

    • Hi Barbara, what type of Pleco is it? A one gallon tank is too small for any breed of Pleco. At the bare minimum, they need around 10 – 25 gallons depending on the species. You might find that the tank size is whats preventing it from growing. Thanks, Robert

  4. Hi,
    Just thought I’d share with you that our Plecos have bred. We have circa 15 young ones in the tank now and they’re great! I’d post a photo but don’t seem to be able.

  5. I have two plecos and a Raphael catfish in a 55-gallon tank. I have to bring city water from a friend’s house because we have well water which is heavy in iron. When I first moved here, I set the tank up with well water and my poor fish, all cherry barbs, died overnight. Since then, for ten years I have filled and changed the water in my tank with city water. It’s a major chore. I recently moved the tropical fish to a 10-gallon tank, which is more manageable. I need to know if I can use well water for my plecos and catfish. We have shubunkins, goldfish, and a koi in pre-water softener well water, all thriving. Will the water, either pre- or post softener, kill the plecos and or the catfish?
    Robert: Would you please send a response to my email in case I can’t find the website again?

    • Hello,

      I don’t have much experience in using well water but I’d imagine if its heavy in iron it won’t be suitable for any of your fish. I’ll leave your comment here in case someone with experience of keeping fish in well water stumbles across it! Thanks, Robert

  6. Hello, I have two tanks I run with well water. One is a 37 gallon with Electric yellow cichlids and a ten gallon community tank. I use a water conditioner when I do water changes. The ph in my water is a little high (7.4) but I haven’t had any problems in my community tank which has 8 guppies, one gourami and ghost shrimp. Cichlids prefer a high ph so also no problems there. I would highly recommend taking a water sample to your local fish store. Also, running your tap for a few minutes before using the water will keep the levels down of any metals present. I hope this helps!

    • I’ve kept Plecos in my 55g tank for 20 years (Slinky x9 yrs, Scribble X10+ yrs) and have always had well water. The old house had a water conditioning system. My new house is also well water (from the same underground aquifer) but no conditioning system. My fish have done fine at both places, without any treatment needed.
      Well water varies by location, so it’s likely your high iron is due to your locale. Here may be a treatment available to remove iron and make it safe for your fish, not sure about that though. Have your water tested by a pond store or a reputable aquarium supply store for the best result.
      I must applaud your devotion. Importing city water to clean your tank must be a hassle. I wouldn’t want to do it, and I really love my fish.

  7. The Pleco I have now is kinda nuts. He is very active during the day and less at night. I have kept fish my whole life and never had one so active, especially during the day. He is well fed with a variety of food. Loves the part sand bottom on one half the tank and regularly demolishes my live plants. He is up to about 8” now. A beautiful fish.

    • My current 10 yr old pleco is fairly active during the day too. The pleco I had before him was definitely nocturnal.
      Recently, my pleco has been aggressive with my Angelfish on two occasions. It really shocked me because they have been tank mates for several years without any issues. Not sure why he went wacko, but the angel stays away from him now.

  8. We have a thirty-gallon tank that includes two plecos. One day, we were admiring the fish, and we noticed in the corners of the tank were a total of six baby plecos! After lots of ooohing and awwwing, we settled back with our coffee and thought how lucky we were! After checking on them multiple times during the day, today we noticed that all six seemed to gone. Oh no!! What happened? Should we have removed them from the tank? Please advise if you know anything about baby plecos. Thanks!

    • Hi Elizabeth, Are you sure they are common plecos? The reason I ask is that they are notoriously hard to breed in captivity, in fact it’s pretty much unheard of. Is it possible that they are Bristlenose Plecos? Thanks, Robert

  9. Hi, me and my partner are about to buy a 200L aquarium tank. About 3ft 3 by 16inches. Would a fully grown common pleco manage in that tank?

    • Hi Peach, no they would definitely not be OK in a tank of this size, they require at least 150 gallons (around 560L) when fully grown. Thanks, Robert

  10. Can a small plecostomus fit in a 20 gallon fish tank with a turtle (maybe two?) If not, can you recommend an algae eating fish that does? The turtle is not very big yet, maybe a 3 inch shell. I would like to get another small turtle as well. I do know that eventually I will need a bigger tank. Thanks!

  11. First thanks for a great web page, lots of good information
    I am the owner of two “rescue” plecos that came from a 40 gallon tank, one is 12″ and the other 9″. The thing i like to add is, that Plecos are very adaptive, for example they now have a 180 gallon tank with “lots”(i still think the tank is to small for them) of places to hide, they don’t hide at all, they lie in the open or hang on the front glass most of the day, even with crayfish crawling around them. I like to think that they feel safe and therefore don’t need to hide.
    Even when i clean the tank i sometimes have to “shovel” them out of the way with my hand, and then they really only move just enough.
    So even though the information above is correct, there’s a huge difference in their behavior,
    depending on their environment, which only makes them more interesting to watch.
    I do recommend that when dealing with larger catfish, that you have a good spacing between the top glass and the water surface, or ( as i am forced to have) keep a lightweight top glass on your tank, mainly because like most catfish Plecos, occasionally like to make a small jump or surface turn grabbing a bite of air, So they don’t get hurt, this happens mostly at night so do keep a lid on, dont want a catfish on the floor to be the first thing you see in the morning:)

    • Hi Thore, thanks for sharing your experience. You’re definitely right about each individual fish having their own personality and behaviour. Thanks, Robert

  12. I have a 6000 gal outdoor Koi pond in the Austin, TX area. Would 2 Plecos help me keep the alge growth down? Would the common plecos survive and grow in this enviroment. My Koi are healthy and growing.

    • Hi Tom, the water temperature will need to between 72°F and 86°F, with pH levels between 6.5-7.5. Is the water in the pond likely to dip below those temperatures over Winter in your area? If so, you’ll need to rehouse them over the winter period. The size of the pond is more than adequate, and they are compatible with Koi. Thanks, Robert

  13. Thank you for a wonderful informative article. When I bought my daughter a 10 gallon tank for Christmas one year we went and got Glofish and of course a Pleco. Little did I know 3 years later I’d be purchasing a larger tank for this little Pleco. Store associates don’t tell you all this information. I purchased a 55 gallon tank for our Pleco (and believe it or not 2 glo fish from the original tank) who is now roughly 12-14 inches long. Since then I’ve started researching and learning a lot about Pleco’s. Again, thank you for the information. Do you know of any clubs or websites I could find more information?

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