What an aquarium costs per month, by tank size
Monthly running cost for the most popular tank sizes, using the same typical setups as our calculator presets. Figures are before food, at 17¢ per kWh, with pumps and lights at full rated power. Pick a size for the line-by-line math, specs and FAQ.
| Tank | Footprint (L × W × H) | Freshwater /mo | Reef /mo |
|---|---|---|---|
| 5.5-gallon | 16 × 8 × 10 in | $4.32 | – |
| 10-gallon | 20 × 10 × 12 in | $4.33 | – |
| 20-gallon long | 30 × 12 × 12 in | $9.34 | $22.53 |
| 55-gallon | 48 × 13 × 21 in | $10.61 | $37.71 |
| 75-gallon | 48 × 18 × 21 in | $15.23 | $51.58 |
Reef presets start at 20 gallons because we didn't find solid published equipment data for smaller nano reefs. The 5.5 and 10 gallon pages still estimate the reef supplies. Every number comes from the sources listed in the calculator's tank-size preset notes.
Your size isn't listed?
The running-cost calculator has presets for 14 sizes from 5.5 to 500 gallons, and the 40-gallon reef guide walks through one tank line by line.