How much electricity does an aquarium use?

An aquarium isn't one appliance. It's a stack of devices running on overlapping schedules, and the total draw depends on which ones you're running and how long each stays on.

Heater (25 to 300W):the biggest single draw. A thermostat cycles it on and off to hold tank temperature around 78°F. In a 70°F room, the heater runs about 50% of the time on a year-round average. Winter pushes that closer to 70%. Summer drops it to 30% or lower. Cold-water tanks (goldfish, white clouds) skip the heater entirely.

Filter (5 to 50W): runs 24 hours a day, 365 days a year. A small sponge or hang-on-back filter for a 10-gallon tank draws about 5 watts. A canister filter for a 55-gallon pulls 15 watts. A reef-grade return pump for a 125-gallon pushes 50 watts.

Light (10 to 100W): runs on a timer, typically 8 to 12 hours a day. Planted tanks and reef tanks sit at the high end. Fish-only tanks can run shorter photoperiods.

Protein skimmer (20 to 50W): saltwater and reef setups only. Runs 24/7. Adds about 30 watts on a typical 125-gallon reef.

The math below uses the 2026 US residential average of 18.05¢/kWh from the EIA Electric Power Monthly. Heater duty cycle is set at 0.5 (year-round average in a 70°F room). Lights run 10 hours a day on a timer.

10-gallon nano tropical:

25W heater (0.5 DC) + 5W filter (24/7) + 10W LED (10h/day) = 0.52 kWh per day. Monthly: 15.6 kWh, about $3. Annual: 189.8 kWh, about $34.

55-gallon community tropical:

200W heater (0.5 DC) + 15W canister filter (24/7) + 30W LED bar (10h/day) = 3.06 kWh per day. Monthly: 91.8 kWh, about $17. Annual: 1,117 kWh, about $200.

125-gallon reef:

300W heater (0.5 DC) + 50W return pump (24/7) + 100W LED (10h/day) + 30W protein skimmer (24/7) = 6.52 kWh per day. Monthly: 195.6 kWh, about $35. Annual: 2,380 kWh, about $430.

In a heated 55-gallon tank, the heater alone accounts for 2.40 of the 3.06 kWh consumed each day. That's 78% of the total electricity draw. The filter and light together are background noise by comparison.

Remove the heater entirely (cold-water species like goldfish or white cloud minnows) and the same 55-gallon tank drops from $17 a month to about $4. The heater adds $13 a month to keep the water at tropical temperatures.

The heater also explains why aquarium costs swing with the seasons. In winter, when room temperature drops to 65 to 68°F, the heater cycles about 70% of the time. Monthly cost for a 55-gallon climbs to about $22. In summer, when room temperature sits around 73 to 76°F, the heater cycles at about 30%. Monthly cost drops to about $11.

That's a 2x seasonal swing on the same tank, same equipment, same fish. The thermostat is doing all the work.

A 55-gallon aquarium draws about 128 watts effective around the clock. That's more continuous load than a wifi router (8 to 10 watts), a UPS battery backup (15 watts), or a gaming console on standby (2 to 3 watts).

In gaming terms: a PlayStation 5 played 3 hours a day uses about 219 kWh per year and costs about $40 annually. That same 55-gallon aquarium uses about 1,117 kWh and costs about $200. The fish tank costs 5 times more per year than the PS5, because the tank never turns off.

The heater alone, at 876 kWh per year, draws 4 times the annual energy of the PS5. A piece of equipment most aquarium owners rarely think about consumes more electricity than the most power-hungry gaming console on the market.

The same 55-gallon tank pulling 91.8 kWh per month costs very different amounts depending on where you plug it in. The rate spread between the cheapest and most expensive US states is about 3.6x.

Louisiana (11.5¢/kWh): $11 a month, $128 a year.

Texas (14.5¢/kWh): $13 a month, $162 a year.

US average (18.05¢/kWh): $17 a month, $202 a year.

New York (22.85¢/kWh): $21 a month, $256 a year.

California (31.2¢/kWh): $29 a month, $349 a year.

Hawaii (41¢/kWh): $38 a month, $458 a year.

In Hawaii, a single 55-gallon heated aquarium adds nearly $40 a month to your electric bill. In Louisiana, the same tank costs less than a streaming subscription.

The biggest lever is the heater, and the cheapest way to reduce heater runtime is to cut heat loss from the tank. A tight-fitting lid is the single most effective move because evaporation is the largest source of heat loss in most tanks. Adding foam insulation on the rear glass reduces conductive loss further. Together they can cut heater runtime by roughly 20 to 30 percent, saving about $3 a month on a 55-gallon.

The second lever is lighting. An LED fixture on a timer set to 8 hours instead of 12 cuts lighting costs by a third. Most freshwater fish and many plants do fine on 8 hours. Reef corals typically need 10 to 12, but even there a timer prevents accidental overnight runs.

Room temperature matters more than most hobbyists realize. Every degree you raise the room is a degree the heater doesn't have to cover. Keeping the fish room at 72°F instead of 68°F in winter can drop the heater's duty cycle from 70% to 50% and save $4 to $5 a month on a 55-gallon.

Aquariums sit in the always-on category alongside wifi routers, UPS battery backups, and standby power loads. For lighting-specific costs, see our breakdown of LED strip lights.

For the state-by-state rate data behind these numbers, see electricity rates by state.