How Much Electricity Does a Fish Tank Use?

by Aquarium Scoop | Last Updated: February 3, 2023

Knowing how much electricity your fish tank uses can help keep your electricity bills low and make sure your fish tanks work well. Today, we’ll talk about how much electricity an aquarium can consume and give tips on keeping your electricity costs as low as possible, even with multiple tank setups!

In this article, you’ll learn:

  • What factors affect how much electricity a fish tank uses?
  • Why is it important to reduce the amount of electricity your fish tank uses?
  • What are some tips on how to keep your fish tank’s electric consumption as low as possible? 

What factors affect how much electricity a fish tank uses?

In our experience, the average fish tank costs about $4 a month to keep running, but running multiple tank set-ups can be pretty costly since the overall cost start adding up. 

5 main factors affecting electricity usage:

  1. The size of your tank
  2. The type of filter of your tank
  3. The heater set-up of your tank
  4. The lighting set-up of your tank
  5. The number of fish in your tank

The size of your tank:

Larger tanks require more electricity to run compared to smaller tanks. This is because they need more power to move the water around and maintain the right level of filtration.

Before buying an aquarium, you should consider how much electricity it will use since larger tanks can lead to higher electricity bills. Additionally, the size of an aquarium can also play a role in the number and type of fish that can be kept in it. Fewer fish should go in smaller tanks, while many more can live in bigger ones.

The type of filter of your tank:

An aquarium filter is a critical component of any aquarium system. It helps keep the water in the aquarium clean and healthy by getting rid of physical and chemical waste.  However, different types of filters use different amounts of electricity.

Most aquarium filters are powered by electricity, and the amount of power used depends on the filter’s type, size, and complexity. For example, canister filters use more power than hang-on-back filters. A larger filter with more features, like a multi-stage filtration system, will use more electricity than a smaller filter with fewer features. 

To use less electricity, you need to choose an aquarium filter that is the right size for your tank and has the features you need for your system. 

The heater set-up of your tank:

Heaters are necessary if you live in an area with cooler temperatures, as they help regulate the water temperature inside your tank, so your fish don’t get too cold (which can lead to health problems).

Most heaters also use a lot of electricity, so if you want to save money on your electric bill, choose a model that uses less energy but still heats the tank well. Make sure the model you choose is also the right size for the aquarium. A heater that is too small will have to work harder to reach the temperature you want, which will use more electricity.

Here’s a helpful table you can refer to when purchasing your aquarium heater!

Aquarium Tank SizeHeater Kw
5-10 Gallon (20-40 Liter)25-75 watt
20-25 Gallon (75-100 Liter)50-200 watt
50-75 Gallon (200-300 Liter)400-600 watt


Expert Tip 🧠

Most tropical fish can tolerate up to about 70°F in the short-term without stress, and some can live without heaters in the long-term.

The lighting set-up of your tank:

The lighting set-up of an aquarium is a crucial element of the tank ecosystem. It helps bring out the natural beauty of the fish and plants in the tank and can also be used to control algae growth. Choosing the right lighting set-up for your aquarium is essential, as different setups can vary significantly in energy consumption. LED lights are the most energy-efficient option, as they produce more light with less energy than traditional incandescent or fluorescent bulbs. 

You can also control how long your lights stay on to save energy. For example, if your tank is in a room with a lot of natural light, you may only need to use your lights for a few hours a day. You can use less electricity and save money by setting up your lights correctly.

The number of fish in your tank:

The amount of electricity an aquarium uses can be affected by how many fish are in it. Large tanks with more fish require more filtration, heating, and lighting, all of which require electricity. For example, if there are more than ten fish in an aquarium, the water will need to be cleaned with a bigger filter. This filter will have to run longer to keep the water clean, resulting in higher electric consumption. 

Also, if more than ten fish are in an aquarium, bigger heating and lighting systems may be needed to keep the water at the right temperature and light level. This will also use more electricity. So, when figuring out how much electricity an aquarium uses, it’s important to consider how many fish are in it.

Expert Tip 🧠

You can use a simple online electricity cost calculator to calculate how much you’ll pay for your tank’s monthly electricity bill! Enter your kw/h rate, the wattage of the equipment, and the hours used.

Benefits of reducing the amount of electricity your fish tank uses

Several factors play a role in your fish tank’s electric consumption, which you probably want to reduce. In line with that, here are three reasons why reducing your aquarium’s power consumption is a smart move:

  1. It saves you money in the long run.
  2. It extends the life of your fish. 
  3. It helps protect our planet. 

It saves you money

Even though running an aquarium doesn’t cost much, everyone likes to save money. Plus,  the cost of running an aquarium can add up quickly if you have multiple or large aquarium set-ups.   

Cut down on your monthly electric bill by making simple changes, like using energy-efficient lighting and filters. Making simple, easy changes can save you a few dollars every month.

It extends the life of your fish

Fish are sensitive creatures that environmental changes can easily stress. Running your tank at cooler temperatures requires less power and puts less stress on your fish, so they’ll live longer and healthier lives.

It helps protect our planet

Reducing the amount of electricity used by fish tanks also reduces pollution from power plants. This benefits the environment and helps reduce greenhouse gases that contribute to climate change. The switch to a more energy-efficient fish tank is a win-win for everyone involved!

Expert Tip 🧠

Next time you upgrade your aquarium setup, consider its power usage and consider using energy-saving components like LED lights.

What are some tips on how to keep your fish tank’s electric consumption as low as possible? 

As someone who loves their fish, you probably want to do everything you can to ensure they’re healthy and happy without breaking the bank. Part of that is ensuring their home – a.k.a, your fish tank – uses as little electricity as possible. Not only will this save you money on your monthly electric bill, but it’s also better for the environment!

Here are some tips we’ve rounded up to reduce the amount your fish tank costs you each month:

  1. Keep your aquarium clean. 
  2. Choose suitable filters for your aquarium.
  3. Switch to an air pump in your aquarium.
  4. Add live plants to your aquarium. 
  5. Choose LED lights over fluorescent bulbs for your aquarium.
  6. Reduce the number of hours your aquarium lights are on.
  7. Don’t use a heater in your aquarium. 

Keep your aquarium clean

A dirty fish tank will require more filtration and aeration, which means higher electricity costs. Perform regular water changes and vacuum the gravel to help keep your aquarium clean and reduce how much money you spend each month on electric bills.

Choose suitable filters for your aquarium

A lot of the power consumption for fish tanks comes from the filters.

If you have a basic tank, consider using a smaller filter – By using a smaller filter, you can cut down on the amount of electricity your tank uses each month.

You can also consider switching to a different type of filter – canister filters are typically more energy efficient than hang-on-back (HOB) style filters. If you have a HOB filter, ensure the intake tube is close to the gravel, so water does not need to be pumped as high, saving energy.

Switch to an air pump instead of a water pump in your aquarium

If you have a water pump for your fish tank, consider switching to a high-quality air pump. It uses very little power but provides adequate filtration for most small tanks.

Add live plants to your aquarium

Live plants look great and help oxygenate and remove carbon dioxide from your fish tank’s water. Having live plants in your tanks also means you’ll need to run your filtration system less often, saving you even more money!

Adding live plants to your aquarium also has the added benefit of preserving the water quality of your tank for a more extended period of time, reducing stress for your fish – and you!

Choose LED lights over fluorescent bulbs for your aquarium

LED lights save a lot of energy, so aquarium owners are quickly switching to them. LED lights use significantly less electricity than fluorescent bulbs and last much longer, meaning you save money in the long run. They also emit very little heat, so they don’t require additional cooling.

LED lights are also much brighter than fluorescent bulbs, allowing you to see the colors of your fish and aquatic plants. With all these advantages, it’s no wonder why many aquarium owners are choosing LED lights over fluorescent bulbs for their aquariums.

Reduce the number of hours your aquarium lights are on

If your goal is to view your fish during daylight hours, then only have your aquarium lights on for 8-10 Hours per day instead of 12 or more. One thing you can do to help you do this easily is use an automatic timer for your light fixtures.Of course, the shorter period you have the lights on, the lesser energy consumption! 

Don’t use a heater in your aquarium. 

If possible, try not to use a heater in your fish tank. You can take advantage of natural heat sources like sunlight and room temperature to keep the water comfortable. This is especially useful in tropical climates where the ambient temperature is already warm enough to support most fish species. Explore to see what temperature is comfortable for your fish. You may be surprised that they can adapt to a wider range of temperatures than you think!

By following these simple tips, you can save money each month on your electric bill without compromising the health or happiness of your fish!


How much electricity does a 30-gallon fish tank use?

A 30-gallon fish tank uses an average of 50 watts of electricity. The actual amount of power used may be slightly higher or lower depending on the type and size of the aquarium, but this is a good estimate.

How much electricity does an aquarium consume?

A small aquarium may only use a few watts of electricity, while a large saltwater reef aquarium can easily consume over 1,000 watts. Most of the power usage comes from operating the filter and lighting system.

How much does it cost to run a fish tank per month?

A small freshwater aquarium can be run for as little as $12 per month, while a larger saltwater setup may cost upwards of $120. The cost depends on the size and type of aquarium and the number and type of fish.

How long can fish live in a tank if the power goes out?

It takes a fair amount of electricity to run a fish tank. The average home aquarium uses about 50 watts per gallon, meaning a 10-gallon tank would require 500 watts for the heater and filter.

If you add other features like lights and bubblers, that number can go up significantly. As for how long fish can live in a tank if the power goes out, it depends on several factors.

Most tropical fish can survive without oxygenation for several hours if the water is warm enough. However, if the water temperature drops too low, they will start to suffocate and die within minutes.

Without filtration, ammonia and other toxins will quickly build up in the water and kill the fish. Ultimately, it comes down to how long your backup power lasts and what kind of shape your tanks are in when the power goes out.


The size, filter, heater, lighting set-up of your aquarium, and the number of fish in your tank all play a role in how much it costs to run a fish tank.

Reducing the amount of power your fish tank uses for financial, environmental, and fish health reasons is vital. 

To save money on your electric bill, keep your aquarium clean, choose suitable filters for your aquarium, switch to an air pump in your aquarium, add live plants to your aquarium, choose LED lights over fluorescent bulbs for your aquarium, reduce the number of hours your aquarium lights are on, and don’t use a heater in your aquarium. 

Aquarium Scoop is dedicated to providing the best care for your fish and other aquatic life. We offer a wide range of services to educate aquarium owners on taking care of their fish and other aquatic life, including regular checkups and maintenance, water quality testing and analysis, and fish nutritional counseling.