How Big Does A Plecostomus Get?

Oh, Pleco!

Oh, Pleco!
Oh, Pleco!

One of the most popular and distinctive family of freshwater fish kept as pets are in the plecostomus family. Usually, they are referred to as "plecos" partly because it's a great nickname and also because of an old superstition. It was once thought that if you spoke or spelled out the entire name of "plecostomus", a pleco somewhere would die. So my apologies in advance.

Advantages of Plecos

Plecos are hardy, distinctive and social (as in, they completely ignore other fish - unless it's another pleco). They are also a bottom feeder, which is very helpful for keeping your tank healthy. They sift through the gravel or whatever you use on your tank's floor and eat the food the top feeders may have missed. If their food was left alone, bacteria could grow that could affect the health of the water. They also eat any growing algae. Since you are sure to keep your tank healthy, you will most likely have to buy algae wafers for them to eat. Their food is also easy to find.

And they look so cool. They come in several colors and patterns, including a very striking black and white zebra. The brown types are the least expensive and easiest to find.

Disadvantages of Plecos

Plecos can often be aggressive to other plecos. They also will suck on any sick fish in the tank and can pester a sick fish to death. They are also notoriously difficult for the hobbyist to breed, but you might not want to, anyway.

The main disadvantage of a pleco is that they grow unpredictably. For every pleco seems to grow in their own good time. The majority seem to grow to 18 inches, but only after several years. Some just seem to be content to stay under a foot all of their lives. And still some need to move to ever larger tanks and then a pond. Ask 10 pleco owners about how big and fast their plecos grow, and you'll probably get 100 different stories.

Plecos are not recommended for tanks under 10 gallons. They are sure to outgrow a ten gallon tank eventually, although it will most likely take years. If you only want to keep a ten gallon tank or less, consider a Chinese algae eater instead.

In Conclusion

This writer has seen plecos almost two feet long. However, most plecos never get that big. If you have a large tank or pond, don't completely dismiss the idea of getting a pleco. They are long lived fish that are relatively easy to care for and have a unique beauty. The chances for a pleco outgrowing your tank are small.

If your pleco does turn into a record-setter, please do your best to find him or her a new home. The nice thing about plecos is that they are not to fussy about where they live. Call a pet shop or advertise on Petfinder.com or Craigslist. If you know someone who has a backyard pond or koi pond, ask them if they need a bottom feeder to help keep the pond clean. If there is a public park or college with a man made pond, ask them if the pleco can live there. Don't just dump the pleco in, unless you want to make a lot of enemies fast.

For a last thought, let me tell you about my Dad's pleco. He's about ten years old and still hasn't grown beyond six inches. The tank has just him and one other fish (a glassfish) and he seems to be doing great. So, although the possibility exists that he might outgrow the tank, the odds are he won't.

Minor disagreement between two striking plecos. Film by Jonashansel

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Comments 71 comments

Shep 8 years ago

Great article! I had a hard time finding good info on these guys before now. Good job!


kelly 8 years ago

dumb never have i seen something so weirod!!!!!!!!!!!!!!! i hate bitches that put these things on the web


kyle 8 years ago

hi. you said "If you only want to keep a ten gallon tank or less, consider a Chinese algae eater instead."

i would not recommend a chinese algae eater for a tank less than 30 gallons. they are also large fish (although not as large as a common pleco) growing to 10" and get more aggressive with age. they will eat algae initially, but after 4-5" they tend not to eat it and would rather eat fish food instead, or the slime coat of other fishes. i also wouldn't recommend a common pleco in anything smaller than a 90 gallon tank.


sammie 8 years ago

i have 2 plecos and one has grown huge the other still is smal the big one is a bully not letting my little one eat! getting a new tank and only keeping one pleco per tank!!!


matt 7 years ago

i heard there were plecos i wanted to get one but then found out about their size they get to and got a brisstle nose plec instead in one year they get to abot 7-8cm aprox.


Cheryl 7 years ago

My Pleco is huge! He's about 12" long and quite suddenly outgrew the 6 Gallon take he has taken over. The fish place never told me he would get so big... I recently got a new tank for him. I am attempting to move him, but ever since he jumped out last week, and "walked" across the floor, I get hesitant to even open the top for long. He's such a mellow guy, and I think he jumped because I nipped his fin while trying to vaccum the rocks, I appologized to him for days! I love this fish, and he NEEDS the new tank, so any suggestions on how to get him out of a 6gal tank? I can't get a bucket in there, and I don't think I can grab him firm enough without feeling like I'm squishing him. I removed the other fish that were in the old tank, and he seems to be living large in his tank by himself. He even has funny new habits. He floats with his "nose" out of the water, and lets the water coming out of the filter run into his mouth. He rams the bubble hose so it disconnects, and then floats with his "nose" out of the water and lets the bubbles give him a massage on his back. He's got more of a personality then any fish I've ever owned. I am not even a big fish fan!


jessy 7 years ago

wow that thig is huge and i thought my pleco was big its only about as big as my hand


Aaron  7 years ago

i had one about 4 years ago but my dad made me give it away because it out grew out 4foot tank


Aaron  7 years ago

i had one about 4 years ago but my dad made me give it away because it out grew out 4foot tank


phil 7 years ago

I had one and he just died out of know where.he was about 10" long.I had him for abut 5-6 years.my cat would here him move from across the house and go running.they were great friends.rip


FoxDragon 7 years ago

I have a pleco that is currently 13 1/2 inches, I moved him from a 20 gallon when he was 5 inches long. I used a large net style 'baby breeder' that I very carefully maneuvered under him and scooped him out then dashed him over to the new tank (before this I did water transfers between to two tanks so the new water wouldn't shock him) Since your pleco is so biug, i wouId recommend a pond style 'koi net' to get you're pleco with. Be Carefull of the Spikes! No matter how you do it, the pleco wont be happy with you, so try to have the tanks close together and be quick. I hope the new tank is big, a common pleco can get to 18 inches or more.



davey jones 7 years ago

i am the great cornholeio i need peekada for my bum hole


CJ 7 years ago

If he's still in there, get him out fast! I don't think he's displaying 'interesting' characteristics, I think he's merely trying to fit! Common pleco's should never be in a 6 gallon at any stage in their lives - they need a tank 15 TIMES that size! They are armoured catfish and can be handled without any threat to damaging them. They might not like it but they like living in a sardine tin a lot less!


jess 7 years ago

i have a 60 gal. and a bristlenose is very small what pleco should i use


Rich 7 years ago

I have two plecos in my 37 gal. tank. My tank is about 3 mths old. I got the plecos about the same time with the tank. The plecos were about 1.5" long. Now they are about 8" long. I am looking for a 100 gal. tank now. I never new that a pleco can get so big. When I was younger I had a pleco that never got any bigger than 3" long, in a 29 gal. tank. I told the guy at the pet store, he told me if I wanted to I could bring him in. He also told me that he have seen a 6' long pleco. I never knew that plecos can get that big.


em 6 years ago

I'm sorry to say, but this is the worst advice for someone looking for information on a pleco. A normal pleco grows (on average) 18-24" and should not be kept in a tank smaller than 55 gallons.Plecos that are kept in tanks smaller than 55 gallons die prematurely(usually a year or so). Smaller tanks do slow their growth, but do NOT stunt it. They still reach 18-20 inches it just takes a bit longer, however most die before they can get that big because the slowing of their growth kills them. There are however smaller types of plecos that only grow to 5-6 inches(bristlenose plecos).


Mrs.Barrymore. 6 years ago

Why the hell are you even on this site then KELLY.

You RAT.


gary 6 years ago

i think the best way to move plecos depends on size a small pleco will be fine been moved by a net and for larger plecos the best way is to pick them up just behind the head then lay it on your forearm for support my pleco doesn't seem to mind and he's nearly 2 foot


Kylie 6 years ago

My mom has had plecos all my life and every one has gotten huge! I currently have a 19 year old, 2' pleco and a 3 year old, 6" one that used to be hers. My big guy actually survived the 6 hour transfer between their house and mine in a bucket in the back of a truck. These guys are tough and live a long time. I love my plecos, even if the big one likes to suck on me when I clean the tank.


Andrew 6 years ago

My Common Pleco is about 4 years old and is about 23" long and still growing. I have him in a 150 gallon tank. He lives with my two 24" Tiger Shovelnose Catfish and my 3 24" Gars just fine. I have two other common plecos in another 125 gallon tank that have grown to about 9" within the last year or so. They can grow fast if they have the room.


Tim 6 years ago

My plec is about 18months old if that. He eats everything. But he is now about 15inches long maybe a bit bigger, and still growing. He constantly digs up gravel and rearranges the tank to his liking. Te weird thing tho is that he thinks he's a dog and I always catch him swimming around with twigs in his mouth which I used for tank decoration. Hopeing to get him a big tank soon, 250litre plus, just there so expensive.


saz 6 years ago

i had one and mine named jaws he was so frendley i could stroke him there skin is like sand paper rip jaws he would be 14 this year and he got to just under 20 cm


andrew 6 years ago

i had a pond and a tank and i put 2 in my pond and they reached about 16-18" but in my tank he only grew to about 6 inches but i was also wondering why the pleco in my tank has spikes covering its face and the 2 in the pond don't and they were bought at the same time in the same tank at the store


deosfluviatilis profile image

deosfluviatilis 6 years ago from Pandora's Box

Andrew the spiked one is a bristlenose. That's why it didn't grow as big as the other two.


jake 6 years ago

i have two plecos and they never seem to bother each other. i did not know they were aggressive to each other. an interesting thing about plecos is that they only come out of hiding at night ( even when the lights are on )


zortaini 6 years ago

Hello, We have had our one Pleco for 23 years and she is 22" long! We have a second Pleco that is almost as long which we have had for about 14 years. Both are in a 45 gallon bow front tank and we would like to find them a bigger home! We are very attached to our Plecos and each has it's own personality! We tried to get all of the large Aquariums to take the Plecos but all refused to accept pets! We do not have room for a larger aquarium and are trying to find a better solution for our longtime friends. We need to find out what Winter temperature a Pleco can handle in an outdoor pond as we live in the Carolinas! - thanks


Gazi 6 years ago

I have a blue royal phantom, leopardus pleco, black with White dots flyer pleco, common pleco, royal pleco, clown place and a zebra looking pleco... I have a 60gal tank, is that ok??? They have plenty of bog wood and hiding spaces, they look happy!!


Mia 6 years ago

i have a pleco and he is living perfectly fine in his 10 gallon tank. i plan on getting a betta and a couple mollies. is that ok??i have had him for 9 months. he is only the size of 4 inches.... is that normal???


Molly 6 years ago

i have one common pleco and would like to get another in a 200 litre tank would that be okay??


momo 6 years ago

@molly, no betta splendens do not like any other fish and are aggressive species the do better on their own in a medium sized bowl.


lockie 6 years ago

ok guys i just bought a 45 gallon tank

i have always wanted a pleco but i think i will out grow very fast

i have 2 bristle nose

what type on pleco dosnt get to big?


twilight 5 years ago

Our plecostomus(we call him"plecy")is 13 and a half.My kids are jealous of him because he is a year older then them!


Web Gazelle profile image

Web Gazelle 5 years ago from USA

There a many different species of Plecostomus and not all grow to be over a foot long. The common Pleco that is found in almost any pet store is the one that will grow quickly and get to be about 12 inches long. Then there is the even larger Sailfin Pleco which can grow to be about 18 inches long. If you would like to get a pleco for your tank to help with algae control but you have a small tank then I suggest getting a Bristlenose Pleco or a Bullnose Pleco. Both of those species grow to be only about 5 inches long.


Evan 5 years ago

People are so dumb when it comes to tank sizes and what you can keep in there, it's retarded , I have a 65 gallon with a foothold albino pleco, full-grown parrot fish, and a tiger Oscar, plenty of room for everyone and everybody is happy, no "90 gallon minimum"llmao


rachel 5 years ago

@em : ive kept a pleco in a 5 gallon tank for almost 2 years and it is fine. it just skims around on the bottom for food and it seems to be in perfect health.


dom 5 years ago

dose anyone know how much plecos sell for?

just a common one my friend said the can sell for $400


Katie 5 years ago

I got my lovely common pleco at Walmart for less than $2.50. Within 24 hours of Costy being there, he ate so much algae! He didn't even hesitate. He's around 5.25 inches now, and still growing (got him at around 3 inches)! If you want something smaller, then I suggest a bristlenose catfish which max out in size at 5-6 inches. I've seen both kinds at reputable pet stores.


tanner 5 years ago

mollies bettas plecos can all live together in the same tank. and if u go to sertain websited ull fine the main companion for a betta is a mollie along with snails pleco zebra danio shrimp kuhli louches and so on. there only aggressive to other bettas. females can live with any amount of other female bettas.


tanner 5 years ago

also this is very helpful info for any new pleco owner. iv owned fish all my life and been breeding and selling bettas mollies guppies pleco neon tetras coolie louches quite a few dif typs of catfish snails goldfish zebra danios and so on my list goes on forever iv been breeding fish for about 12-13 years now.


adrian 5 years ago

I have a community tank set up, mollies, few platys a beta (female fighter) few zebra danios left over from cycling the water a lace gourami and a pleco about 4.5", they all get along great and have never been any trouble at all. my tank is 75 litre so about 20 gallon. what I would say to be careful of is that mollies are quite prone to white spot if their immune system is taking a beating from bad water quality / whatever is stressing them and the treatments for this are really hard on your pleco as he has plates not scales, consider having a tank for the pleco to be in while you administer treatments for the scaled fish as they will really make him upset, irritate his skin and could eventually kill him.


paul 5 years ago

I'm a new pleco owner any tips on what fish I can put with him


Silver Poet profile image

Silver Poet 5 years ago from the computer of a midwestern American writer

These cool fish are very interesting. I used to have one. I didn't know they could get so big!


Suzy 5 years ago

I have had my pleco for 6 yrs in my 67.32 gallon tank and he is still only 20cm long. I knew they got big and was quite surprised when it didn't grow as fast as i expected him to. So I'm quite happy with that.


Moi 5 years ago

All of you people recommending tank sizes for every fish, just STOP! if someone can buy fish they can decide their fish tan size. they could even cook the fish and eat it, so thanks but no thanks!


lizzards 5 years ago

everywhere i search, i see plecos only live 7-15 years. mine is approx. 20yrs this yr. i got it in 1991 and it was a few yrs old then. it's approx. 22" long and appears to be quite healthy still. just FYI folks. i guess it depends on how well you care for them.


pissed off person 5 years ago

grrrr

i got a tank given to me (15 gallon) and it had a 12 inch sailfin pleco in it! :@

my parents wont let me give him to a better home!

so now i'm stuck with a massive pleco, which overwhelms the bio-filtration and leaves shit everywhere, everyday!


Pleasant Person 5 years ago

Have you concidered surreptitiously eating it? There are many tasty recipes for catfish on teh internets.

Then you will have an empty 15 gallon tank and a full stomach.


Plecoman 5 years ago

What's goin on! How long does it take for a pleco to get full size? Someone help a brudda out! Cool


MotherOfTwo 5 years ago

I have a 55 gal tank. There are abt 15 feeder fish and one make betta in there. Two days ago I added 2 pleco algae eaters that are about two inches long. They are all ignoring each other so far. My kids and I are excited to see them grow! From all the posts I guess we will have to wait to see how fast they grow. I hope they live as long as all of yours! Good luck to everyone with all their fish!


vlh 5 years ago

This article has more misinformation and bad advice than any I have ever read.


seb 5 years ago

-comon and sailfin plecos get big... if you cant house it, start looking for a new home in advance.

-try not to cycle a tank with a plec in, they are botom feeders and so find it harder to get oxygen from the surface when under stress (eg. high nitrites).

-the size of you'r tank will affect the final size, but not by more than 30% or so, if you'v got a sailfin plec that's 6" and 20 years old, its probably not a sailfin....

-allot of fish shops sell plecs without talking to you about size requirements, this is because they assume someone buying fish has researched them before going to the shop.

-if you have made the mistake of buying a comon plec for you'r 10gal tank, just ask around, there are plenty of people who will take free fish.


Paul 4 years ago

i have a 2 yr old common pleco that is around 6 inches long in a 30 gallon tank. he hasn't grown at all since i moved 2 months ago, his behaviour is still basically the same, the tank is pretty clean so i mean he has to be eating. one thing i have noticed tho is that abt every 10-15 mins he likes to swim really quick to the top and hit the lid of my tank, my friend told me this is normal and that he isn't trying to hurt himself but im more worried about the 50 guppy fry that just popped out of the momma, will they get out of the pleco's way quick enuf or should i take the fry out till they get bigger???


Shereen 4 years ago

To Chery:

I think your pleco is actually showing signs of distress.. A Pleco will not try and jump from his tank because hes happy. I have moved mine before by using a net and my hands only. Once its under him cover him and the net firmly with your hand (be prepared sometimes their spiky fins poke you and their bodies are very rough and muscular) and then just run him over to the other tank and lower him into the water, that is already prepared for him so hes not sent into shock. What's most important is that you hang on to him they are very fast ans strong fish. He really needs to be moved to another much larger tank immediately though. There really is no pretty way to do it unfortunately...but a net is usually helpful because he will have a much harder time trashing out of it as you move from one tank to the other. Good luck.


jim 4 years ago

is anyone interrested in buying a

15 inch sailfin catfish im located in pa and can be reached at 5704846438

Sailfin catfish Pterygoplichthys multiradiatus asking for bids if interrested


marineman 4 years ago

I agree with some, and disagree with many here, One helpful thing to do is before you buy your pleco, ask the fish manager or someone who feeds and takes care of the fish at the store, ask how big the pleco has grown and how long they have had it. plecos vary, mine is only 6 inches after 1 year and that's the size i got him at.


marineman 4 years ago

oh and another great fish to get is a Butterfly Hillstream Loach! check it out! they only reach about 4-5 inches and take a long time to grow, and are very excellent fish!


chris 4 years ago

Hi there was just wondering about my baby plecs some have damaged skin i think its where they have been attacked maybe not sure what would you suggest i do to help them recover fully?


brooke 4 years ago

Just rescued a ft long plecos fm an idiot who was keeping him in a TUPERWARE CONTAINER!!! His fins were damaged & skin damage, open sores... added " API General Cure" to his new tank (80 gal hopsital tank, will b moved to 150 gal) and he is recovering. Please Please Please don't but a Plecos unless you are prepared to deal with a very large fish... if you don't have the proper facilities the fish will suffer needlessly. Horribly cruel.


conor 4 years ago

hi i just bout a leopard pleco does any 1 no how big they grow


Chris S 4 years ago

This morning my 16 year old Pleco died. I bought him as a tiddler in '96 and he grew into a 16 inch monster.

He will be sadly missed. :0(


jojo 4 years ago

my pleco is about 9inchs he is 2yrs old and in a 55gal. withall kinds of small fish. he lives under a fake tree that is hollow and he moved all the gravel out from under it. I also have a out door pond I live in carlsbad n.mex. would like to know about moving him out doors but dont want to freeze him in the winter HAS ANYONE DONE THIS


Richard Pears 4 years ago

I catch them all the time here in Houston. They are in the Bayous here.. I have caught them at 2.5 feet. They will destroy a cast-net, lol.. I think they are put in the bayous by the city to help with the algae. They are giant. and hard as a rock.


Valerie 4 years ago

I have a fun pleco story! Years ago I had a pleco that was about 7 inches long. Well I woke up one morning and he was gone! So I looked all around the tank and eventually looked behind the tank. There he was, covered in dust! I picked him up and was so sad. He was completely covered and dry... It seemed he'd been out of the tank a while. Then, suddenly, his little mouth moved! I dropped him back in the tank and he lived! I now have 2 pleco's (one about 6" and another is a baby at about 1.5") and so far they are getting along. My tank is 55 gallons. Me and my 2 sons LOVE our plecos!


Lucky 4 years ago

I have an 18 in. Pleco in my 55 gal. Shark tank and he is great. A bit quiet but its a fish. Of course if i lived in a shark tank i would be quiet as well! No worries though they all get along great. Its like they have an understanding, he cleas the tank and they leave him alone. Lol. Even my 14 in. Ropefish leaves the beast alone.


JayJay 4 years ago

I own a breeding pair of bristlenose plecos and they're only a few inches long.

They get along fine with a few zebra danios and a pearl gourami.


hc 4 years ago

On of those fish was a red tailed shark and the other was a pleco..


Bill Rouse 4 years ago

My last Pleco was 13 inches when he died and now I have two new ones which are growing fast, where can I find info on their sex and type pleasebecause the two are different not only in colour but physical features too


hayden 4 years ago

my pleco was crit big uchbut it died becouse i fed it to m


darissa 3 years ago

I have a 19" Pleco about 8yrs old....I love him....I just moved him from a bow front to a 55 gal and he is in Pleco heaven! I tried to move him and wasn't successful at first....then I got a clean hand towel, let it soak up the water over top of him until it gradually floated down over him. I picked him up from the back of the head and his tail and he did not struggle at all....I was very pleased and thought I would mention this method of moving a bigger pleco....great stories on here, I've enjoyed them....


Dann 3 years ago

For smaller tanks definitely aim to buy a Clown Pleco, they will never grow much bigger than 4-5 inches for a start and are wicked algae eaters!

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