ReefBay data · Reef tank sizes
What size reef tank do most people have?
Updated November 2, 2026 · Sample: 11,506 tanks · Recomputed weekly
These numbers come from real tank profiles in the ReefBay app, not from a survey. Every saltwater tank with a volume counts once.
Key findings
The median reef tank in ReefBay is 40 gallons (151 liters), based on 11,506 saltwater tank profiles. Half of all reef tanks are this size or smaller.
The most common reef tank size is 20 gallons (76 liters), 6.3% of tanks, followed by 40 gallons (151 liters) at 4.6% and 75 gallons (284 liters) at 4.3%.
36.4% of reef tanks are nano tanks of 30 gallons or less, and 16.7% are more than 100 gallons.
The average (mean) reef tank size is 65 gallons (246 liters). The middle half of tanks fall between 20 gal and 79 gal.
52.4% of reef tanks list a sump. Among tanks with a sump, the median sump holds 18 gallons (70 liters).
Reef tank sizes by range
Share of 11,506 saltwater tanks in each size range.
- 10 gal or less 6.0% (687)
- 11 to 20 gal 19% (2,196)
- 21 to 40 gal 25% (2,891)
- 41 to 75 gal 24% (2,784)
- 76 to 120 gal 14% (1,592)
- 121 to 200 gal 8.6% (988)
- More than 200 gal 3.2% (368)
The 15 most common reef tank sizes
Display volume as entered by the owner. Tanks entered in the other unit are converted and rounded.
- 20 gal 6.3% (720)
- 40 gal 4.6% (533)
- 75 gal 4.3% (494)
- 15 gal 3.7% (429)
- 32 gal 3.3% (384)
- 14 gal 2.5% (293)
- 25 gal 2.2% (258)
- 55 gal 2.2% (255)
- 90 gal 2.1% (246)
- 10 gal 2.1% (245)
- 30 gal 1.9% (222)
- 50 gal 1.8% (209)
- 53 gal 1.8% (209)
- 26 gal 1.7% (200)
- 60 gal 1.7% (199)
Summary
| Tanks counted | 11,506 |
|---|---|
| Median size | 40 gal |
| Mean size | 65 gal |
| Middle half (25th to 75th percentile) | 20 gal to 79 gal |
| Nano tanks (30 gallons or less) | 36.4% |
| Large tanks (more than 100 gallons) | 16.7% |
| Tanks with a sump | 52.4% |
| Median sump volume | 18 gal |
| Saltwater vs freshwater profiles | 11,989 saltwater, 281 freshwater |
Method
- Source: tank profiles and logs created by ReefBay app users. ReefBay is a reef aquarium app for iOS and Android.
- Excluded: deleted tanks, deleted accounts, ReefBay staff and test accounts.
- Counted: every saltwater tank with a display volume between 1 and 5,000 US gallons (about 18,900 liters). Volumes entered in either unit are converted, so every tank counts the same.
- Sump volume is the user-entered sump volume. Tanks with no sump volume count as no sump.
Cite this page
You may reuse these numbers and charts with a link to this page (CC BY 4.0). Suggested citation:
ReefBay. "What size reef tank do most people have?" November 2026. https://reefbay.com/stats/tank-sizes
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