Tank reference

Innovative Marine NUVO 40

24 × 20 × 16 in

Key stats

Dimensions (L × W × H)

24 × 20 × 16 in

61 × 51 × 41 cm

Volume (raw, outside)

33 US gal

125.8 L · 7680 in³

Water volume (with glass inset)

30 US gal

111.8 L

Manufacturer nominal

40 gal

Differs from raw — manufacturer rounds down for shipping

Footprint

3.33 ft²

480 in²

Filled saltwater weight

380 lb

172 kg · 114 lb/ft² floor

Filled freshwater weight

336 lb

152 kg

Recommended glass (annealed)

10 mm

0.394 in · safety factor 3.8

Heater size (78°F target)

119 W

Redundant pair: 2× 75 W heaters

Substrate (2" sand bed)

47 lb

CaribSea Special Grade · 3 × 20-lb bags

How many gallons is a 24 × 20 × 16 in tank?

A 24 × 20 × 16 in aquarium contains 33 US gallons by outside dimensions. The math:

24 × 20 × 16 = 7680 in³
7680 ÷ 231 in³/gal = 33.25 US gal
33.25 × 3.785 = 125.8 L

In practice, actual water capacity is 30 gallons after subtracting 0.375" of glass thickness on each side. Manufacturers typically market this as a 40-gallon tank for round-number simplicity.

For a different shape (cylinder, hex, bow-front) or to enter custom dimensions, use the full aquarium volume calculator.

How much does a filled 24 × 20 × 16 in tank weigh?

  • Saltwater reef (with ~30 lb live rock + 1" sand bed): 380 lb (172 kg)
  • Freshwater (with 20 lb gravel, no rock): 336 lb (152 kg)
  • Empty glass only: approximately 63 lb
  • Floor load: 114 lb/ft² (saltwater filled)

Floor-load warning: at 114 lb/ft², this tank exceeds the 40 lb/ft² typical residential live-load rating. Place over a load-bearing wall or get a structural assessment before installing upstairs.

Full breakdown including equipment, sump, and custom rock weight: aquarium weight calculator.

Glass thickness for a 24 × 20 × 16 in tank

Using the Wisner hobby formula with a 3.8 safety factor, this tank requires:

  • Annealed (regular float) glass: 10 mm minimum (0.394")
  • Tempered glass: 5 mm minimum (tempered is ~4× stronger than annealed)

Most commercial tanks at this size ship one thickness step up for additional safety. See the glass thickness calculator for the full formula and Starphire (low-iron) options.

Heater wattage for a 24 × 20 × 16 in tank

In a warm room (~70 °F ambient) targeting 78 °F, this size tank needs about 119 W of heating. The conservative reefkeeping practice is to run two heaters at 75 W each: if one fails stuck-on, the other isn't powerful enough to cook the tank alone; if one fails stuck-off, the remaining one slows the temperature drop while you replace it.

For cold-room or cool-basement adjustments: heater wattage calculator.

How much sand or gravel for a 24 × 20 × 16 in tank?

  • 2" sand bed: ~47 lb of CaribSea Special Grade aragonite (3 × 20-lb bags)
  • 4" deep sand bed (DSB): ~94 lb
  • 1" shallow / aesthetic: ~24 lb

Other substrate brands (Nature's Ocean, Tahitian Moon, Eco-Complete): substrate calculator.

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Equipment for this tank

Salt, sand, heater, and light picks sized for a 33-gallon tank. All on Amazon — prices and stock change daily.

Affiliate links. As an Amazon Associate, reefcalcs earns from qualifying purchases.

FAQ

How many gallons is a 24 × 20 × 16 in tank?
A 24 × 20 × 16 in aquarium holds approximately 33 US gallons by outside dimensions (125.8 L). After subtracting a standard 0.375" glass thickness on each interior wall, the actual water capacity is about 30 US gallons. Manufacturers commonly market this as a "40-gallon" tank.
How much does a filled 24 × 20 × 16 in tank weigh?
A 24 × 20 × 16 in saltwater reef tank with ~30 lb of live rock and a 1" sand bed weighs about 380 lb (172 kg) filled. Freshwater with no rock comes in lighter, around 336 lb. Floor load is roughly 114 lb per square foot — most residential floors are rated for 40 lb/ft² live load, so confirm before placing upstairs.
What glass thickness do I need for a 24 × 20 × 16 in tank?
Using the Wisner hobby formula with a 3.8 safety factor, a 24 × 20 × 16 in tank needs at least 10 mm annealed (regular float) glass. Tempered glass can be 5 mm and still meet the same safety margin. This is the calculated minimum — most commercial tanks at this size ship with one step up for safety. See the glass thickness calculator for the full math.
What size heater for a 24 × 20 × 16 in tank?
For a tank in a warm room (~70 °F ambient), this size needs roughly 119 W of heating. For redundancy, run two heaters at 75 W each — heaters fail, and a single point of failure on tropical fish or coral is expensive.
How much sand or substrate for a 24 × 20 × 16 in tank?
A 2-inch sand bed in this footprint (24" × 20") needs approximately 47 lb of CaribSea Special Grade aragonite, or about 3 20-lb bags. For a deep sand bed at 4 inches, double that.
Is a 24 × 20 × 16 in tank good for a reef?
Yes — the 24 × 20 × 16 in footprint is well-suited to a reef tank. The width gives enough front-to-back depth for aquascaping. Tank height is shallow — easy on lighting but limits vertical aquascape.

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