Pet water fountain vs. aquarium: running cost
A pet water fountain is cheaper to run: about $3 a year versus $77 for an aquarium at typical use and 17.99¢/kWh, a $73 difference.
| Pet water fountain | Aquarium | |
|---|---|---|
| Typical watts | 2 W | 135 W |
| Watt range | 1–60 W | 30–1,000 W |
| Typical use | 24 hours a day | 24 hours a day |
| Energy per year | 18 kWh | 426 kWh |
| Cost per hour | 0.04¢ | 0.9¢ |
| Cost per day | 0.9¢ | 21¢ |
| Cost per month | $0.26 | $6.39 |
| Cost per year | $3 | $77 |
| Per year in Hawaii (43.51¢) | $8 | $185 |
Compare at your rate and settings
What drives the difference
- Pet water fountain: Pet fountains run tiny 1-3 W pumps around the clock, about 17 kWh a year. Heated outdoor bowls draw 25-60 W on a thermostat.
- Aquarium: Watts are total heater, filter and light ratings. The heater cycles and the light runs about 8 hours, so a heated 29-gallon tank averages about 50 W, roughly 400 kWh a year. Reef tanks with pumps and lighting use far more.
Ways to cut either cost
Wireless pet fountain
Motion-activated pumps run only when the pet drinks.
See options on Amazon LED aquarium light
Uses about half the power of fluorescent fixtures.
See options on AmazonWe may earn a commission from qualifying purchases. It never changes the numbers we show. Disclosure.
Frequently asked questions
Which costs more to run, a pet water fountain or an aquarium?
At typical use and the U.S. average rate (17.99¢/kWh), an aquarium costs about $77 a year versus $3 for a pet water fountain. That's $73 more, or 24.3× as much.
How many watts do pet water fountain and aquarium use?
A pet water fountain typically draws 2 W (range 1–60 W). An aquarium draws 135 W (range 30–1,000 W). Watts alone don't decide cost. Hours of use, cycling and standby matter just as much.
Rates: EIA, 12 months ending 2026-07. Methodology.