Do Plecos Need a Filter? Everything You Need to Know

Plecos need tank filters, probably more than most other tropical fish. They produce a lot of waste that can lead to poor water quality and a mess to look at in your tank. So, they’ll need a heavy-duty filter and frequent water changes.

This can be a bit confusing since people are often told that plecos are good pets with algae-cleaning properties. Still, that doesn’t mean you should leave your tank without a filter.

In this article, we’ll go in-depth about plecos’ filtration needs. So, keep reading to find the answers to all your questions!

Why Do Plecos Need a Filter?

Naturally, all fish require filters and heaters.

That’s because, through the nitrogen cycles, filters help the growth of beneficial bacteria in your tank. In turn, these bacteria consume toxic ammonia and produce nitrite, thus creating a complete ecosystem.

Plus, filters act as air pumps by circulating the water to the tank’s surface. This way, the tank water is constantly oxygenated through gas exchange.

However, plecos could need filters more than other fish types, and as they get bigger, they’ll require even more filtration.

Here’s why:

Plecos Have a Large Bioload

The main reason you’ll need a filter for your plecos is that they’re incredibly messy fish with a relatively large bioload.

In other words, plecos eat a lot and produce a lot of waste. So, they need constant filtration.

Bottom-Dwelling ≠ Cleaning Fish

It’s a common misconception that plecos don’t need filters, especially since people call them ‘cleaning fish’ often. Yet, this couldn’t be further from the truth.

While plecos are bottom-feeding fish, you shouldn’t expect them to do all the cleaning in the tank. The best you could get out is a reduced risk of algae overgrowth.

Snowball Pleco L142

Saving Up on Space

Filters can significantly decrease the size of your tank since the reason you need more water is to prevent waste accumulation.

Typically, an adult pleco will need a tank size of about 75 to 80 gallons. This means that if you want to keep your tank clean without a filter, it’ll need to be much larger and can even reach 150 gallons!

Keeping Your Plecos Stress-Free

Every time you manually clean your tank, you’re subjecting your plecos to a lot of stress. As a result, your pleco might look pale, hide, or swim abnormally.

So, in a way, getting a filter can significantly reduce all the effort you have to make to maintain your plecos’ temperament!

Meanwhile, you also have something to gain from this equation since you’ll be saving yourself some exhausting maintenance chores.

Can I Keep Plecos in a Tank Without an Automated Filter?

While this could be done, this isn’t really a situation that you want to be in. If you keep your fish in a tank without a filter, you’re slowly poisoning them to death.

Accordingly, if you want to keep your fish from swimming in their own waste, you’ll need to filter the tank manually. However, it’s better to limit this for emergencies, like if your filter breaks down.

Here’s what you’ll need to consider:

Tank Size and Frequent Water Changes

For one, you’ll need a big enough tank.

You’ll also need to change the tank water regularly. Yet, you don’t need to completely dump out the water daily.

Instead, changing about 1/4th of the tank water with fresh water every day will be sufficient to keep the tank relatively clean.

Additional Cycling

Some types of beneficial bacteria live around your tank. These bacteria have a crucial role in balancing the nitrogen cycle, but sadly, their population drops without adequate filtration.

As a result, you’ll have to cycle your tank more often to restore the number of good bacteria.

Aerating the Tank

Filters play an important role in aerating the tank and keeping the oxygen saturation high. So, without a filter, you’ll need an alternate source of oxygen.

You can do this by keeping live plants in your filter. However, your plecos might eat them.

Another option would be scooping the tank water above the aquarium and slowly pouring the water back in. This method ensures the water picks up enough oxygen while being poured back into the tank.

What Happens to Plecos Without Automatic or Manual Filtering?

Without automatic or manual filtration, your aquarium will be prone to many toxins and diseases, some of which can be fatal.

For one, ammonia, the tank’s main waste product, will build up. Additionally, nitrite will also accumulate inside the tank.

The high ammonia and nitrite levels can be extremely harmful to any fish, including your plecos.

You should keep an eye on some alarming symptoms of ammonia poisoning, including:

  • Reduced appetite
  • Low activity
  • Gasping for air near the lid
  • Resting at the bottom

To avoid this problem, you need to have a filter operating at all times inside your tank. Even if you don’t have a filter for your plecos, you should always do it manually.

It’s also crucial to have an ammonia and nitrite testing kit.

How Long Can Plecos Go Without a Filter?

It’s hard to tell how long your plecos can survive without a filter. This life-threatening situation can go on for around five days before your fish can’t handle it anymore.

So, it might be a good idea to have an extra aquarium filter for your plecos tank for emergencies.

The Takeaway

Since plecos are bottom-feeding fish, many people might think the fish will clean the tank themselves. So, do plecos need a filter? Or is that a waste of money?

As opposed to popular beliefs, plecos actually require heavy filtration. Since they have an extremely large bioload, their tanks can get dirty quite quickly.

In addition, filters serve more than just cleaning the tank. They help aerate the water, keep beneficial bacteria in the tank, and reduce stress on you and your pets.

Naturally, your plecos won’t survive without a filter for long.