20 gallon high tank: dimensions & setup math
24 × 12 × 16 inches (L × W × H). Rounded planning dimensions; measure your tank.
20 nominal gal · about 225.59 lb with water, estimated glass and 2-inch gravel.
Estimated working water uses 85% of nominal: 17 US gal. The volume tool instead applies 85% to geometric volume. Neither is a measured fill.
Eight answers for this tank
- Tank volume
19.95 US gallons · 75.51 litres
- Gravel & substrate
33.33 lb gravel for a 2-inch bed
- Heater wattage
60–100 W planning range
- Filter flow
80–120 GPH for a community
- Stocking guide
288 in² surface · 24-inch swimming length
- Water changes
4.25 US gal for a 25% water change
- Dechlorinator dose
2 mL Prime for 20 US gal of new water
- Filled weight
About 225.59 lb filled (without stand)
Plan around this footprint
This 20 gallon high plan uses 24 × 12 × 16 inches and 288 in² of floor. Compared with the 15 gallon column (187.34 in²), its footprint is 53.73% larger. Small setup: leave an open swimming lane and add livestock in stages after the filter is cycled. The 20 long has a 30 × 12-inch floor versus 24 × 12 for the 20 high: 25% more substrate at the same depth, despite the same nominal capacity.
Dimensions and limits
Aqueon size chart. Listed dimensions are representative, not exact catalog measurements. Names identify marketed sizes; geometry explains why the calculated gallons can differ. Weight excludes the stand, rocks and equipment.