Tank reference
Innovative Marine NUVO 10
20 × 10 × 10 in
Key stats
Dimensions (L × W × H)
20 × 10 × 10 in
51 × 25 × 25 cm
Volume (raw, outside)
9 US gal
32.8 L · 2000 in³
Water volume (with glass inset)
7 US gal
27.0 L
Manufacturer nominal
10 gal
Differs from raw — manufacturer rounds down for shipping
Footprint
1.39 ft²
200 in²
Filled saltwater weight
109 lb
50 kg · 79 lb/ft² floor
Filled freshwater weight
109 lb
49 kg
Recommended glass (annealed)
4 mm
0.157 in · safety factor 3.8
Heater size (78°F target)
29 W
Redundant pair: 2× 25 W heaters
Substrate (2" sand bed)
20 lb
CaribSea Special Grade · 1 × 20-lb bags
How many gallons is a 20 × 10 × 10 in tank?
A 20 × 10 × 10 in aquarium contains 9 US gallons by outside dimensions. The math:
20 × 10 × 10 = 2000 in³ 2000 ÷ 231 in³/gal = 8.66 US gal 8.66 × 3.785 = 32.8 L
In practice, actual water capacity is 7 gallons after subtracting 0.375" of glass thickness on each side. Manufacturers typically market this as a 10-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 20 × 10 × 10 in tank weigh?
- Saltwater reef (with ~7 lb live rock + 1" sand bed): 109 lb (50 kg)
- Freshwater (with 20 lb gravel, no rock): 109 lb (49 kg)
- Empty glass only: approximately 27 lb
- Floor load: 79 lb/ft² (saltwater filled)
Floor-load warning: at 79 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 20 × 10 × 10 in tank
Using the Wisner hobby formula with a 3.8 safety factor, this tank requires:
- Annealed (regular float) glass: 4 mm minimum (0.157")
- Tempered glass: 4 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 20 × 10 × 10 in tank
In a warm room (~70 °F ambient) targeting 78 °F, this size tank needs about 29 W of heating. The conservative reefkeeping practice is to run two heaters at 25 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 20 × 10 × 10 in tank?
- 2" sand bed: ~20 lb of CaribSea Special Grade aragonite (1 × 20-lb bags)
- 4" deep sand bed (DSB): ~39 lb
- 1" shallow / aesthetic: ~10 lb
Other substrate brands (Nature's Ocean, Tahitian Moon, Eco-Complete): substrate calculator.
Equipment for this tank
Salt, sand, heater, and light picks sized for a 9-gallon tank. All on Amazon — prices and stock change daily.
Instant Ocean Reef Crystals — 200 gal box
Cheapest reef salt with decent reef chemistry. Used to start.
View on Amazon →
AI Prime 16HD
Best small-tank reef light. Up to 24×24 in coverage for LPS/mixed.
View on Amazon →
Bubble Magus Curve 5 skimmer
Best budget skimmer for tanks up to 80 gal.
View on Amazon →
Cobalt Aquatics Neotherm heater
Most-recommended reef heater. Shatter-resistant.
View on Amazon →
CaribSea Arag-Alive Special Grade reef sand
Live aragonite, no rinse, 2-inch grain. Reef default.
View on Amazon →
Mag-Float aquarium glass cleaner
The hobby standard magnetic algae scraper. Sizes for any tank.
View on Amazon →
Refractometer for saltwater + calibration fluid
Calibrate with 35 ppt fluid monthly. Replaces hydrometers.
View on Amazon →
Salifert KH/Alkalinity test kit
The hobbyist standard for alkalinity testing.
View on Amazon →
Affiliate links. As an Amazon Associate, reefcalcs earns from qualifying purchases.
FAQ
- How many gallons is a 20 × 10 × 10 in tank?
- A 20 × 10 × 10 in aquarium holds approximately 9 US gallons by outside dimensions (32.8 L). After subtracting a standard 0.375" glass thickness on each interior wall, the actual water capacity is about 7 US gallons. Manufacturers commonly market this as a "10-gallon" tank.
- How much does a filled 20 × 10 × 10 in tank weigh?
- A 20 × 10 × 10 in saltwater reef tank with ~7 lb of live rock and a 1" sand bed weighs about 109 lb (50 kg) filled. Freshwater with no rock comes in lighter, around 109 lb. Floor load is roughly 79 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 20 × 10 × 10 in tank?
- Using the Wisner hobby formula with a 3.8 safety factor, a 20 × 10 × 10 in tank needs at least 4 mm annealed (regular float) glass. Tempered glass can be 4 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 20 × 10 × 10 in tank?
- For a tank in a warm room (~70 °F ambient), this size needs roughly 29 W of heating. For redundancy, run two heaters at 25 W each — heaters fail, and a single point of failure on tropical fish or coral is expensive.
- How much sand or substrate for a 20 × 10 × 10 in tank?
- A 2-inch sand bed in this footprint (20" × 10") needs approximately 20 lb of CaribSea Special Grade aragonite, or about 1 20-lb bags. For a deep sand bed at 4 inches, double that.
- Is a 20 × 10 × 10 in tank good for a reef?
- Yes — the 20 × 10 × 10 in footprint is well-suited to a reef tank. The narrow front-to-back depth limits aquascape complexity — possible for a reef, but expect to keep rock structures simple. Tank height is shallow — easy on lighting but limits vertical aquascape.
Run your own numbers
Last reviewed