Do Molly Fish Need A Bubbler? (And Which One To Get)

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Establishing an aquarium for molly fish can pose a challenge, particularly for beginners who are new to this hobby.

A common question aquarists ask is, “What are the specific requirements for these fish, particularly in terms of using bubblers (or air stones)?”

In this article, I will discuss whether bubblers are actually necessary for molly fish, and provide my personal recommendations.

Let’s dive in.

Do Molly Fish Need A Bubbler?

While molly fish don’t specifically require a bubbler in their tank, the addition of one can be beneficial to their overall health and well-being.

The main function of a bubbler, or air stone, is to increase the oxygen level in the water, which can support the fish’s respiration.

It’s not a necessity for molly fish, but a bubbler can certainly contribute to an optimal environment.

Let’s delve into why this is beneficial for molly fish:

  • Oxygenation: A bubbler increases the water’s oxygen levels. Molly fish, like all fish, rely on oxygen dissolved in water for respiration. Higher oxygen levels help ensure molly fish have an adequate supply for optimal bodily function.
  • Water Movement: A bubbler generates water movement. This can mimic the flowing water of a molly fish’s natural habitat, providing a more comfortable and stimulating environment.
  • Gas Exchange: Bubblers facilitate improved gas exchange at the water’s surface. This process is crucial in removing harmful gases like carbon dioxide and introducing fresh oxygen, which is beneficial for molly fish.
  • Prevention of Stagnant Water: The consistent water movement created by a bubbler helps prevent stagnant water, reducing the chance of harmful bacteria or algae growth, which could negatively affect the health of molly fish.

Also Read: Molly Fish Tank Setup

Choosing The Perfect Bubbler For Molly Fish

Before looking online for a bubbler, there are a few things to consider:

1. Consider The Size Of Your Aquarium

When selecting a bubbler for your molly fish, the size of your aquarium should be a prime consideration.

The efficiency of a bubbler largely relies on the size of your tank, as not all bubblers are made equal.

A small bubbler might not sufficiently oxygenate a large tank, and conversely, a powerful bubbler might create excessive water movement in a small tank.

Key aspects to note when considering the size of your aquarium include:

  • Tank Volume: The larger your tank, the more powerful a bubbler you’ll need. For instance, a 100-gallon tank inhabited by molly fish will require a stronger bubbler than a 20-gallon tank.
  • Number of Fish: More molly fish in the tank means more oxygen consumption. Therefore, a tank with a higher population of fish may require a more powerful bubbler.
  • Tank Shape: Tanks with a larger surface area facilitate better gas exchange. In deep, narrow tanks, a bubbler can help improve oxygenation throughout.

2. Look For Bubblers With Adjustable Airflow

An adjustable airflow feature is a valuable aspect when choosing a bubbler for molly fish.

This functionality allows you to regulate the amount of air produced by the bubbler, enabling you to customize the tank’s environment to your molly fish’s needs.

Here’s why adjustable airflow is important:

  • Controlled Environment: Adjustable airflow allows you to tailor the water movement to the molly fish’s comfort, as they typically prefer calm water.
  • Flexibility: It provides flexibility for any changes you might make in your tank setup, such as adding more molly fish or changing the tank’s dimensions.
  • Prevents Stress: Too much water movement can stress molly fish. Being able to adjust the airflow helps ensure their environment remains peaceful.

3. Evaluate The Noise Level

Noise level is an often overlooked but essential factor in choosing a bubbler for molly fish.

A noisy bubbler can be disruptive to both your household and potentially stressful to the molly fish themselves.

Here is what you should know:

  • Quiet Environment: Molly fish thrive in a peaceful environment, and a quiet bubbler helps maintain this tranquility.
  • Household Disruption: A less noisy bubbler ensures the aquarium doesn’t disrupt household peace, particularly in quiet rooms or at night.
  • Fish Stress: Excessive noise can stress molly fish. While more research is needed in this area, maintaining a quiet environment is generally beneficial for fish health.

4. Prioritize Durability And Quality

The durability and quality of a bubbler are essential considerations for the long-term health of your molly fish.

A well-constructed bubbler will not only last longer but also maintain consistent water conditions for your fish.

Here’s why durability and quality matter:

  • Longevity: A high-quality, durable bubbler will last longer, ensuring consistent conditions for your molly fish over time.
  • Reduced Maintenance: Better quality bubblers often require less maintenance, freeing you from frequent equipment checks and replacements.
  • Cost-effective: In the long run, investing in a quality product will save you money, as you’ll avoid repeated purchases of cheaper, less reliable bubblers.

5. Opt For Energy-Efficient Options

Opting for an energy-efficient bubbler offers benefits beyond cost savings on your electricity bill – it also contributes positively to the environment.

Energy-efficient devices often perform at the same level as their non-efficient counterparts, offering the same benefits to your molly fish without the additional energy consumption.

Energy-efficient bubblers offer several advantages, including:

  • Decreased Electricity Expenses: By using energy-efficient bubblers, you can effectively reduce your electricity costs, resulting in long-term savings.
  • Environmentally Friendly: By using less energy, these bubblers have a smaller carbon footprint, contributing less to environmental degradation.
  • Performance: Energy-efficient doesn’t mean less effective. These bubblers can provide the same benefits to your molly fish as less efficient options.

Considering all these factors, my personal recommendation is the Hygger Aquarium Air Stone (link to Amazon).

What Can Replace Bubblers?

While bubblers are effective in oxygenating aquarium water, there are alternative methods for aerating your tank.

1. Manual Aeration

Manual aeration is one method that can serve as a replacement for a bubbler in your molly fish tank.

This method involves physically stirring the water or pouring it back and forth between two containers to introduce oxygen.

Nonetheless, it can be labor-intensive and may not be feasible for larger tanks or extended periods of use.

Key aspects of manual aeration include:

  • Labor-Intensive: Manual aeration requires consistent effort and may not be suitable for those looking for low-maintenance solutions for their molly fish tank.
  • Limited Efficacy: The amount of oxygen manual aeration can introduce is limited and may not suffice for large aquariums or a large number of molly fish.
  • Stress for Fish: The physical agitation of the water may stress the molly fish, so it’s important to employ this method with caution.

2. HOB Filter (Hang-On-Back Filter)

A Hang-On-Back (HOB) filter can be a viable alternative to a bubbler for a molly fish tank. 

These filters not only clean the water but also create surface agitation, which promotes gas exchange and introduces oxygen to the water.

Reasons for considering a HOB filter include:

  • Dual Purpose: HOB filters clean the water and promote gas exchange, providing a two-in-one solution for your molly fish tank.
  • Customizable Flow Rates: Some HOB filters offer adjustable flow rates, enabling you to control the level of surface agitation.
  • Suitable for Various Tank Sizes: HOB filters come in various sizes, making them suitable for a wide range of molly fish tank volumes.

Also Read: Do Molly Fish Need A Filter?

3. Air Pumps

Air pumps are not strictly necessary for molly fish but are beneficial for their health and wellbeing.

They enhance the water quality and general environment for these fish in several ways:

  • Oxygenation: Air pumps aid in oxygenating the water, which molly fish require for respiration. In a densely populated tank, an air pump can help maintain adequate oxygen levels.
  • Water Circulation: Molly fish thrive in flowing water. Air pumps provide this by creating currents, mimicking the natural habitats of molly fish and preventing stagnant areas in the tank.
  • Waste Management: Air pumps contribute to efficient waste dispersal, reducing toxic buildup. This helps maintain a clean environment, essential for the health of molly fish.

Also Read: Do Molly Fish Need An Air Pump?

4. Incorporating Live Plants

Incorporating live plants in your molly fish tank can serve as a biological substitute for a bubbler.

Through photosynthesis, plants generate oxygen, assisting in the oxygenation of the aquatic environment.

However, it’s crucial to establish a balance, as plants also utilize oxygen during periods without light.

The advantages of integrating live plants include:

  • Natural Oxygen Generation: During the hours of sunlight, live plants undergo photosynthesis, producing and releasing oxygen into the water, beneficial for molly fish.
  • Visual Enhancement: Live plants contribute to the aesthetic appeal of the aquarium, offering a visually stimulating environment for molly fish.
  • Additional Perks: Beyond their oxygenating role, live plants provide molly fish with shelter, assist in the absorption of excess nutrients, and help inhibit the growth of algae in the tank.

However, remember that these alternatives are not perfect replacements for a bubbler.

They each have pros and cons and may or may not be suitable depending on the specifics of your molly fish tank.


For those of you who are in a rush, here is a brief summary of what I discussed earlier:

  • While not necessary, using a bubbler in a molly fish tank can be beneficial for their health and well-being.
  • Bubblers increase oxygen levels, which support molly fish respiration and bodily functions.
  • Water movement created by a bubbler mimics the natural habitat, providing a comfortable environment for molly fish.
  • Bubblers facilitate improved gas exchange and help prevent stagnant water, reducing the risk of harmful bacteria or algae growth.
  • When choosing a bubbler, factors such as aquarium size, adjustable airflow, noise level, durability, and energy efficiency should be considered.