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Plecostomus Jumping Out of Its Tank? Best Solutions

Author: Nicole Malczan

You recently decided to add the Plecostomus or suckermouth catfish to your aquarium. You did a lot of research on the fish’s diet and environment, and so far, you haven’t had any issues there. Your problem is your Plecostomus tries to jump out of the tank any chance it gets. How do you stop this issue?

To keep your Plecostomus from jumping out of its tank, we recommend the following measures:

If you’re stumped on why your Plecostomus is trying so fervently to escape, then you’re not going to want to miss this article. In it, we’ll explain the reasons why Plecos jump as well as elaborate more on the above solutions so you can put an end to this bad behavior.

Why Does the Plecostomus Jump Out of Its Tank?

The Plecostomus, affectionately nicknamed the Pleco, is a bottom-feeding fish with a mouth like a sucker so it can clean up food on the pebbles or stones in your tank. This species also has a propensity to jump, so if your Pleco has started this unwanted habit, trust us when we say you’re far from alone.

Getting to the bottom of why your Pleco has begun trying to get out of its tank will help you solve the issue. Here are some common reasons this jumping happens.

Electrical Shortages

You likely have some electrical connections to your fish tank, be those overhead lighting, an in-tank heater, or a filter. When you go to clean these accessories, ensure they’re in working condition. Also, keep the cords out of the water as much as you can.

Electrical shortages from a filter or heater cord being submerged or these accessories being old can hurt the Pleco. Your Plecostomus then jumps so they can get away from this source of danger.

Fish Bullying

This is something that goes for every species of fish, but some fish are better suited to others. You always want to research a fish species’ tankmates and only add those to the tank with your fish of choice.

Otherwise, the other fish can gang up on the newbie because they naturally don’t get along. Ignoring the issue can lead to your new fish getting injured. Unaddressed injuries can become infected and, with enough repeated harm, your fish could even die.

If everything else seems good with your Pleco’s tank but they’re still trying to jump out, you might want to take stock of the other fish you’ve added to the tank. The chances are pretty good that your poor Pleco is being bullied!

Bad Water Quality

Ideally, you want to clean your fish tank every week or two. While you clean, inspect your filter for poor performance, replace roughly 10 percent of the water (15 percent if the water is especially gnarly), and remove the gravel through a siphon so you can clean out any uneaten food and debris.

Failing to do this will leave the water murky, dirty, and overall, unpleasant. Your Pleco won’t want to be stuck living in such low-quality water, so they’ll try to jump and get out whenever they can.

To Get Some Space

The Plecostomus is a huge fish. When it reaches maturity, this species may be as long as 15 inches, and in its native environment, it’s not unheard of for the Pleco to reach lengths of 24 inches.

If your tank can’t accommodate a fully-grown Pleco, then your fish will undoubtedly begin trying to leave said tank. The same can be true if your tank is adequately sized but you have so many fish in there that the Pleco feels like it doesn’t have any room of its own.

How Do You Prevent the Plecostomus from Jumping Out of Its Tank?

As a fish owner, you know how scary it can be to wake up one morning, check your aquarium, and see one of your fish is missing. Your Pleco could have jumped out in the middle of the night and you just discovered him or her now.

Most species of fish are only able to live without water for a matter of minutes. Others can go for a few hours, and the Pleco is one of them. This large fish can last upwards of 30 hours without water provided the Pleco had enough time to gather oxygen in their stomach beforehand.

So sure, if you notice that your Pleco is missing right away and begin looking for it, even if the fish has been out of the water all night, they’ll likely have survived their jump out of the tank.

What if you don’t notice though? What if days go by before you realize you’re down one Pleco? By that point, it’s almost definitely too late and your fish is likely dead behind your tank. That’s not a fun sight to have to find!

To prevent your Pleco’s untimely death, make sure you begin implementing these measures to keep the fish in their tank.

Give Your Pleco Time to Adjust to Its New Environment

If you just brought your Pleco home, then they may not necessarily be super comfortable with their new environment right away. On average, it takes the Pleco about an hour or two to familiarize itself with its home.

What some Pleco owners do is open the bag your Pleco came in, let the bag float in the tank, and then add water to the bag in 15-minute increments. Then, after an hour or so, you can release the fish into the tank outright.

Do keep an eye on your Pleco during the first hours of its first day in its new home, as it may be more likely to jump then. Once 24 hours have passed, the likelihood of the fish jumping lessens somewhat, well, provided you’re otherwise taking care of your Pleco.

Oxygenate the Water

If you’re not already doing so, you must get into the habit of oxygenating your tank. Besides your Pleco trying to jump out any chance it gets, you can also tell that your fish tank is low on oxygen in the following ways:

The sooner you oxygenate your tank, the better it will be not only for the Pleco, but for the rest of your fish in the tank as well. The best and most convenient way to induce oxygen is to use an air pump. You can plug this into your wall or buy a battery-powered version that should work even in a power outage.

Speaking of power outages, know that if your battery-powered air pump fails, you can always oxygenate the tank yourself. Grab a tall cup, fill it with water, raise your arm up high, and then pour the water in from that high up. Adding water at this distance introduces oxygen, especially if you keep repeating the pouring.

That said, make sure you add a bowl or plate at the bottom of the tank to prevent substrate disturbances.

Use a Tank Hood or Lid

In addition to any of these methods, it’s always a good idea to cover the top of your fish tank so your Pleco can’t get out. Whether you prefer a tank hood or a lid, secure this covering to your fish tank so your Pleco can’t dislodge it with the force of their jumps.

Ensure Your Pleco Has a Big Enough Tank

What size fish tank do you have for your Pleco? If it’s anything under 150 gallons, then it’s simply too small to support the length of this sizable fish. Maybe if your Pleco is young you can get away with a smaller tank, but upon reaching maturity, its tank must be at least 150 gallons. If you have the space in your living room or den, feel free to increase the tank size even further so your Pleco has plenty of room to swim.

Improve Water Quality

Besides a lack of oxygenation, another issue that can lead to your Pleco jumping is poor water quality. Like we said earlier, make sure you’re cleaning your tank every week or two, no less often than that. If your tank is especially filthy, feel free to remove even more than the 15-percent recommended water limit. Also, get into that substrate and rinse it thoroughly so there’s no half-eaten food added back to your tank.

Add Pleco Tankmates Only

To prevent Pleco bullying, you should only have fellow catfish tankmates living with the Pleco. Here are some fish to consider that are friendly with the Pleco and vice-versa:


The Plecostomus or Pleco is a catfish species that can grow quite large. This fish also has a propensity for escaping its tank. This happens due to water quality issues, lack of oxygen, electrical shocks in the tank, too little space, or fish bullying.

Your Pleco doesn’t have to jump out of its tank all the time. Now that you know how to contain your fish, you can enjoy life with your Pleco and vice-versa!