How Much Does It Cost to Run an Aquarium per Day and Month?

Source: Planning watts of 100 and 24 hours a day, hours a day, because the pump and heater cycle and lights run on a timer. Price: 17.23 cents per kWh, the 2025 US residential average from EIA Form EIA-861.

The monthly cost is 8% of the $150.68 average US electric bill. It runs all year, so the yearly cost is twelve times the monthly figure.

One figure cannot fit every home. These three cases show how much the answer moves with the equipment and the hours.

The lowest case costs $3 a month and the highest $38. Use the calculator above to match your own.

The same aquarium costs different amounts depending on the state, because the price per kWh differs. Here are the three cheapest states, the US average and the three costliest, for the same 73 kWh a month.

Source: U.S. Energy Information Administration, Form EIA-861 (final 2025 data). Price is residential revenue divided by sales and includes fixed charges.

See electricity rates in every state to find your own.

An aquarium uses a filter pump that runs all day, a light that runs on a timer and, for tropical fish, a heater that cycles to hold the temperature. The heater is usually the largest part of the average draw, and it works harder in a cool room.

Tank size, species, the temperature of the room and the type of lighting decide the cost. A reef tank with strong lights and a chiller uses much more than a small freshwater tank. LED lighting uses less than older fixtures.

The range for this kind of appliance runs from about 20 to 400 watts. At 24 hours a day that is $3 to $50 a month, which is why checking the label on yours is worth the minute.

• Use LED lighting on a timer and do not leave it on around the clock.
• Keep the tank away from drafts and out of cold rooms, and use a lid to cut heat loss.
• Choose a heater sized to the tank, and an efficient pump.

Next step: Appliance cost calculator. For general ideas, read how to lower your electric bill.

Other appliances in the outdoor and extras group: Pool Pump, Hot Tub, Dehumidifier, Humidifier.

The cost is watts divided by 1,000, times hours, times your price per kWh. The 100 watts is a planning figure for this kind of appliance, set from typical product ratings, and the 24 hours is an assumed day of use. Neither is copied from a federal table. Federal guidance describes the method and warns that real wattage varies, so we publish our own typical ranges and label them as such. Prices come from EIA Form EIA-861 for 2025.

The calculation is the standard one used in the U.S. Department of Energy's consumer guidance on estimating appliance energy use. Wattage varies by product age and features, so the label on your own appliance beats any average. Read more in our methodology.