How Long can Fish Live without Air Pump or Filter

How Long can Fish Live without Air Pump or Filter?

Fish are wonderful pets. They are colorful, don’t smell, and need little maintenance. Plus, who doesn’t feel calmer in a room with a fish tank? 

However, while fish make great pets, many people are concerned about the cost and maintenance of setting up an aquarium. Initial costs include but aren’t limited to the tank, the fish, substrate, food, decor, air pump, and water filter.

Continued maintenance involves cleaning the tank, making sure algae doesn’t build up and make your fish sick, feeding your fish and keeping an eye out for any signs of illness or infection. 

Regarding the air pump and water filter, which are often the costliest components of aquarium equipment, it’s understandable if you balk at the price tags.  

It is believed that most fish can live up to 2 days in completely still water without a pump or filter. However, there are some things you can do that will prolong the lives of your fish.

Read on to learn more about the importance of air pumps and water filters in your aquarium. 

How long can fish live without air pump or filter?

Most fish can live about 2 days without an air pump or filter. But this can vary greatly depending on the factors listed below. 

  • Size of the tank 
  • Number of fish
  • Water temperature
  • Type of fish

Let’s break down each of these bullets and discuss the variables. 

Size of the tank

Larger tanks have more water volume, which helps dilute any impurities and leaves a higher oxygen reserve for the fish. Though despite larger tanks having more oxygen and fewer impurities, they usually have more fish, which is detrimental to water quality – which we’ll get to below. 

Number of fish 

The more fish are in a tank, the more waste is produced, and the more oxygen is consumed. Fish in crowded tanks won’t survive as long without an air filter as tanks with one or two fish. 

Water temperature

If you have fish that thrive in cooler water, like goldfish, then they’ll likely survive and thrive without a pump. Warm water, however, retains less oxygen and causes fish stress, especially those species that prefer lower temperatures. 

Stress makes fish more susceptible to disease and death. So avoid drastic temperature changes to a tank that has no pump or filter. 

Type of fish

While most kinds of fish benefit from having air pumps in their tanks, some species prefer still water and get agitated by the bubbles caused by air pumps. Betta fish and goldfish are two species that prefer still water and won’t benefit from an ordinary air pump. 

Fish species that prefer lower water temperature also live longer without an air pump, as cooler water retains more oxygen than warmer water. 

Importance of Air Pump and Water Filter

What does an Air Pump do?

Air pumps oxygenate the water, providing extra oxygen for your fish that they need for survival. Oxygen can also be added to a tank through live plants or air stones – small, round stones that spit bubbles into the tank and oxygenate the water. 

What does a Water Filter do?

Water filters, as its name implies, filters out all the toxins and impurities in the water. This is especially important in aquariums with multiple fish who produce a lot of waste.

Filters keep the water clean and play an important role in the chemical balance of your tank. If your fish produce too much waste and you don’t have a filter, dangerous toxins – like those emitted from fish excrement – build up inside your tank and can potentially make your fish sick. These toxins can also lower oxygen levels. 

Do you Need an Air Pump? Signs to Look for

According to most experts, many species of fish can live long and healthy lives without an air pump. However, since the point of an air pump is to oxygenate the water, your fish are susceptible to not getting enough oxygen if you forgo the pump. 

Are your fish getting enough oxygen? Signs to look for that indicate low oxygen levels are: 

  • Fast, rapidly moving gills – this means the fish are struggling to breathe
  • Hanging out at the surface of the water to get more oxygen
  • Lethargic, resting more than usual

To get an accurate reading of the oxygen levels in your tank, get a portable dissolved oxygen meter or an oxygen test kit. Most pet stores sell them in the aquarium section. 

If your fish are showing any of these signs, getting an air pump might be necessary for the health of your aquatic species. 

How do I Care for Fish Without a Pump or Filter?

Sometimes power outages, equipment failure, or other factors can leave you in a situation where your fish are without an air pump or filter. 

If you find yourself in such a situation, there are special steps you must take to help your fish survive as long as possible. 

  1. Frequently change the water – this helps remove toxins and replenishes the water’s oxygen, contributing to healthier fish.
  2. Use a water conditioner – this helps purify the water in the tank. Water conditioners are sold in bottles in most pet stores. 
  3. Stabilize water temperature – avoid drastic changes in temperature, as unstable water temperature can stress your fish and make them susceptible to disease. 

Other tips, such as stirring up the surface water to make bubbles, are a good temporary fix for an immediate oxygen boost for your fish.

Oxygen test kits are also good to have on hand, so you know if the oxygen levels in your tank drop to a dangerous level. 


Air pumps and filters are highly recommended for aquarium owners, as they prolong the lives of your fish and ensure clean, oxygenated water.

While frequent water changes, using a water conditioner, and stabilizing the water temperature are great for short-term care of fish without a pump or filter, it isn’t recommended for long-term aquarium ownership. 

Proper research is key to knowing how to care for different types of fish and keeping your aquarium a healthy environment for your new pets.