How to Manually Generate Oxygen in Aquariums

A Simple Solution

By
Stan & Debbie Hauter
Stan & Debbie Hauter
Stan and Debbie Hauter are aquatic experts and writers with three decades of professional experience in the field of saltwater fish aquariums and pet fish. They have worked in many aspects of the aquarium pet fish industry, including owning a fish collecting business.
Learn more about The Spruce Pets' Editorial Process
Updated on 03/07/26
air bubbles in aquarium
Credit:

manannan_alias_fanch / Flickr / CC BY 2.0

Key Takeaways

  • Fish cannot survive long without oxygen during a power outage, but manual aeration can help maintain oxygen levels.
  • Pouring water into the tank from a height adds oxygen and circulates water; repeat as needed based on fish behavior.
  • Battery-powered air pumps and ammonia-reducing products are essential tools to prepare for extended power outages.

During a power outage, an aquarium can remain safe for a while without filtration, but the fish cannot survive long without the oxygen normally added by a powered air pump. You can easily add oxygen manually if you do not have a battery-operated air pump or an emergency power source. This manual method also helps to circulate the water. Learn what to do when the power fails.

How to Manually Oxygenate Your Tank

You can add oxygen to your tank by slowly pouring water into it from a height. As the water falls, it captures air and adds oxygen to the tank. The amount of oxygen added depends on the height from which you pour the water and the number of repetitions. Follow these simple steps:

  1. Use a clean cup, pitcher, or any container to scoop and fill it with aquarium water.
  2. Hold the filled container above the aquarium and pour the water back into the tank. Repeat this process multiple times

There is no specific guideline for how often to repeat this, as each aquarium varies. Assess your tank to determine the best intervals. When unsure, perform it more frequently. If the fish begin surfacing for air, it is time to increase aeration.

illustration of how to create oxygen during a power outage
Credit:

The Spruce / Wenjia Tang

Tips

  • Pouring water can disturb the substrate. To prevent this, place a small, heavy plate or bowl in the tank and pour water over it.
  • If using the floating hot water container method to manually generate heat in the aquarium, periodically pour water over the containers. This helps circulate warmth, as most heat from the containers remains near the surface.

Battery-Powered Air Pumps

Battery-powered air pumps can be useful during power outages. However, most are not very powerful and may not efficiently aerate the entire tank. Regularly test these pumps to ensure reliability in emergencies. The most dependable battery backup air pumps operate on AC power and switch to an internal rechargeable battery during outages. These are effective when you are not home.

Test Your Water for Ammonia

If your system is shut off for an extended period, regularly test the water for ammonia. If ammonia levels increase, have an ammonia-reducing product like Kordon's AmQuel ready to prevent poisoning.

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