Do Plecostomus Need A Filter / Air Pump? {Why Is My Pleco Gulping For Air?}

Are you wondering if you can keep your plecostomus in a tank without a filter or air pump? Will they be able to clean the tank enough without the need for a filter? In this article, we’ll discuss if plecostomus need a filter or an air pump.

Do Plecostomus Need A Filter / Air Pump? A Plecostomus creates massive amounts of waste that grossly outweighs the amount of algae cleaning they do to keep a tank clean. A filter is absolutely necessary. If your plecostomus is gulping for air at the surface, you need an air pump to aerate the dissolved oxygen in the tank. 

Why Do Plecos Need A Filter?

We are discussing a fish that may have one of the largest bio-loads out of all your marine life in your tank. Maintaining water quality without a filter in a tank with a single pleco is going to be a huge challenge.

You will need:

  • 4-7 water changes per week
  • A very large tank over 75 gallons
  • living plants
  • frequent cycling of a tank

Water Changes

Many plecostomus get stressed during a water change. You may notice that their color becomes more pale as they feel fear or discomfort from new water being added in.

Do so slowly. Without a filter this is going to be arduous and very frequent from 25% daily water changes or 40-50% changes every other day.

75+ Gallon Tank

A 40-50 gallon tank is not going to cut it for a plecostomus that grows over 14 inches. The waste they produce will surely spike ammonia levels in a smaller sized tank.

They need the room to move and grow. A 50 gallon unfiltered tank will surely cause poor water quality levels and make your plecostomus stressed.

Living Plants

Plant help to oxygenate the tank. The oxygen dissolved into the tank, but an air pump or the current produced by a filter will help to aerate it.

Plants are helpful for providing hiding spaces, but will not be able to replace the function of a filter for a plecostomus that carries such a large bio-load.

Frequent Cycling

Without a filter media, the beneficial bacteria that you need to balance the nitrogen cycle will prove to be very challenging.

You will most likely lose the bacteria battle with harmful parasites and infections taking charge without the beneficial bacteria that a filter’s media helps to provide. You will be forced to cycle your tank more often.

YouTube video

Why Do Plecos Need An Air Pump?

Are you seeing your plecostomus gulping for air at the surface of your tank? There are two main reasons why this happens:

  1. Not enough dissolved or aerated oxygen in the tank
  2. Your pleco might have swim bladder problems

Dissolved Oxygen & Aerated Oxygen

Sometimes your planted area producing dissolved oxygen is not getting around to the entire tank. Oxygenating the tank by adding more plants may not cut it.

The air pump help to aerate what is dissolved to make sure your pleco resting in the corner of the tank is getting enough air. If not, you may see your plecostomus swimming up to gulp air at the surface.

Swim Bladder Disease

It may not be a disease, but buoyancy issues are common in plecos. They may swim upside down or tilted because of a swim bladder that is malfunctioning or is injured from an accident.

Although there is no cure, you pleco can survive with swim bladder problems if the tank’s water quality is clean and there is enough oxygen flowing throughout.

Should I Get An Air Pump For My Pleco?

Have you ever seen a tank with air pump start to malfunction? When the air pump breaks down, you may see the marine life inside trying to swim up to the surface to gulp air.

An air pump will agitate the water’s surface. It will provide the gaseous exchange needed to reach down and move around the dissolved oxygen all the way to the substrate where your pleco is located.

Is your plecostomus breathing rapidly, gasping or becoming increasingly lethargic? It might be time to consider an air pump to assist. You may even notice your plecostomus enjoying the bubbles from an air pump or air stone as it swims through, around or rests underneath them.

Do Plecos Like Currents?

Your plecostomus originates from fast flowing waters in the wild. The faster the water flows, the more oxygen is able to dissolve and circulate. Your plecostomus is used to well oxygenated waters.

Our mission is to do our best to replicate natural environments as much as we possibly can. An air pump is an easy solution to mimic their naturally oxygenated, fast flowing habitat in nature.

Do Plecos Need Warm Water?

The water temperature range for a pleco should be within 74-80° F. This is quite warm, but replicates their South American waters. Warmer water however, holds less oxygen. You will need to make sure the oxygen is being dissolved, agitated and aerated for your plecostomus to be comfortable.

An air pump and frequent water changes along with vacuuming the substrate will keep oxygen levels high while clearing harmful debris or preventing stagnation from stressing your plecostomus.

How Can I Prevent My Plecostomus From Jumping Out of the Tank?

Have you ever seen a plecostomus jump out of a tank? You may think it’s unlikely due to their large size, but frequent trips to the surface to gulp air may cause the urge to jump out.

We can prevent this with a tank lid or making sure our plecos have enough air circulating in the tank with an air pump. Without a filter or air pump, frequent water changes are going to be even more crucial.

When changing the water with chlorinated tap water, there will be chemical reaction with your tank water that will cause your plecostomus a brief moment of difficulty breathing. A filter and air pump will reduce the need to change the water so often.


Plecostomus is a type of suckermouth catfish that excretes massive amounts of waste. They clean algae, but they make a bigger mess in your tank. A filter is a must. An air pump is optional, but recommended to prevent your pleco from swimming up to the surface to gulp air.

We need the oxygen to flow and the current from a filter or movement of water with an air pump to help to mimic the naturally fast flowing waters that plecos are used to in the wild.


Thanks for visiting for another article on plecostomus that we greatly enjoy taking care of in our aquariums. Check out more of our articles on the variety of marine life we research and keep. Bye for now!

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.