Pleco Fish Full Size?

Topic: How large can common plecos grow to? I have one that is 5 inches long right now and wondering how big they grow to. What size tank should these fish be in? I was told they can grow pretty large so how big of a tank is being realistic?

Veggie Rounds 4.2oz.
List Price: $5.99
Price Disclaimer


*Awarded Answer
Posted by Nick R: These fish can grow over 24 inches long BUT IT TAKES a long time for this to happen. If you plan on keeping larger fish like this I would say a tank size minimum of 75 gallons. Don’t worry too much though because pleco catfish are super popular among aquarium owners. It really just depends on if you plan on keeping bigger tanks or smaller fish tanks. I personally have always kept bigger tanks because the fish are cooler.. but that’s just me.

  • pleco fish sizeHere is a popular photo that is going viral in the groups. This shows you how big these fish get.
  • Can a common 5-6 inch pleco and a school of otocinclus be in the same 55 gallon tank?
    Edit: this isn’t my tank, Girlfriend’s. I don’t condone a pleco in such a small tank but wasn’t my choice. Will upgrade tank as he gets bigger but won’t go to 100+ until we move.
  • Common pleco needs a lot of space. They get pretty big.
  • Always plan on the full grown size of each species. So common plecos grow to 18-24 inches. 55 gallon is not big enough.
  • You could do a clown pleco and otos or some other smaller pleco.
  • Yea 55g is good for now but definitely by the time he’s 10” I’d upgrade him
  • I was just recently reading online that a full grown (I believe it said full grown) pleco can become semi aggressive. Idk anything about the fish you wish to add but I would do some research. My guy is currently 7-8 inches and he’s gentle. He’s going into an indoor pond of his own so I didn’t do too much research on it.
  • They’re only aggressive with others or if fish try to take their food. Then they’ll switch and become a dinosaur. They’ll even attack piranha
Cobalt Aquatics 1.5" Round Pleco Cave
List Price: $11.79
Price: $9.62
You Save: $2.17
Price Disclaimer
  • Katie I won’t judge you for having a common pleco.
    Believe me I understand the situation .
    If your friend doesn’t haven’t the ottos yet I would recommend holding off on buying them.
    A common pleco can be very territorial and might not tolerate the ottos .
    If you have them already make sure they have plenty of hides and cover to break up the line of site and provide shelter.
    Wish you and your friend the best and Marry Fishmass
  • Saved my boy from my mates aquatic shop. when I got him he was in terrible shape, split fins and bite marks etc, recovered well, Lord knows what the guy who brought him in kept him with.
  • I have one that big, and it pains me to see them as juveniles still for sale as not many people have room for 5ft 500 litre plus tanks to keep them once they grow, I hear of so many outgrowing & getting killed
  • My pleco is mean enough to hang with my 5 piranhas. He is really crabby. He is now the boss. Piranhas are scared of him. He slammes into them if they get in his way.
  • I rescued one that size that was in a 55 with a 2 ft bala and a 9 inch kissing gourami. Needless too say I wasnt putting him in my planted 75 so he went too a guy with a 300 gallon tank.
  • I have a question/problem…. so I did a water change today and my Oscar got a hold of my pleco and it seem that the pleco stuck in the Oscars mouth… pleco still moving I think it’s using the suction to avoid being eaten… what should I do???