40 gallon long tank: dimensions & setup math
48 × 12 × 16 inches (L × W × H). Rounded planning dimensions; measure your tank.
40 nominal gal · about 459.11 lb with water, estimated glass and 2-inch gravel.
Estimated working water uses 85% of nominal: 34 US gal. The volume tool instead applies 85% to geometric volume. Neither is a measured fill.
Eight answers for this tank
- Tank volume
39.9 US gallons · 151.02 litres
- Gravel & substrate
66.67 lb gravel for a 2-inch bed
- Heater wattage
120–200 W planning range
- Filter flow
160–240 GPH for a community
- Stocking guide
576 in² surface · 48-inch swimming length
- Water changes
8.5 US gal for a 25% water change
- Dechlorinator dose
4 mL Prime for 40 US gal of new water
- Filled weight
About 459.11 lb filled (without stand)
Plan around this footprint
This 40 gallon long plan uses 48 × 12 × 16 inches and 576 in² of floor. Compared with the 40 gallon breeder (648 in²), its footprint is 11.11% smaller. Medium setup: place equipment so water circulates along the full length, including behind hardscape.
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.