Precision Aquarium
Calculators & Specs

Rated gallons use outer glass dimensions, but internal water capacity is typically 10%–20% lower due to the thickness of the glass, rim gaps, the volume taken up by the substrate bed, and hardscape displacement.

Water weighs 8.34 lbs per gallon. When factoring in glass, substrate, and stand, a filled setup creates substantial concentrated static load (often 100–150+ lbs/sq ft). Actual floor capacity depends on joist spans, lumber dimensions, and wall support. For tanks over 50 gallons on timber floors, placement near bearing walls and professional assessment are recommended.

The standard formula is (Length × Width × Desired Depth) ÷ 1,728 to get cubic feet. You then multiply that number by the material's bulk density (e.g., standard sand is about 100 lbs per cubic foot).

A 20 Gallon Long offers significantly greater biological stability than a 5-gallon nano tank. Larger water volumes act as a thermal and chemical buffer against rapid ammonia swings, making water parameter maintenance much more forgiving for beginners.

Glass thickness depends entirely on the water depth (which dictates hydrostatic pressure) rather than overall volume. For safety, custom builds require a safety factor of 3.8 to 4.0 using standard architectural float glass.