FishTankCalculators
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Fish Tank Gallon & Volume Calculator

Calculate precise water capacity, substrate displacement, and filled floor load to verify structural safety.

📐 View Mathematical Formulas ▾
L H W
in
in
in
10%
0% (Bare) 10% (Standard) 20%+ (Heavy)

Calculation Results

Gross Volume 0 gal
True Dosing Vol 0 gal
Water Wt. 0 lbs
Filled Wt. 0 lbs
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Dosing Safety: Dose all medications, liquid fertilizers, and conditioners using the True Dosing Volume (0 gal). Dosing to gross sticker volume (0 gal) causes an unintended 0% chemical overdose.

Structural Floor Load

0 PSF

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Why do I need to know my aquarium's volume and weight?

Accurate tank volume is critical for properly dosing medications, water conditioners, and fertilizers. Moreover, the total filled weight dictates where you can safely place your aquarium in your home.

Net Volume vs Gross

Most tanks are never filled to the brim and contain displacement from substrate, rocks, and equipment. We estimate net volume at ~90% of gross volume for medication dosing.

Structural Load Safety

Water weighs 8.34 lbs per gallon (1 kg per liter). A typical 55-gallon tank can weigh over 600 lbs. Always ensure your floor joists run perpendicular to your aquarium stand.

Bioload & Stocking Reference by Species

Common search: neon tetra bioload per gallon, goldfish minimum tank size, guppy stocking 10 gallon. Gross volume alone doesn't tell the full picture — bioload capacity depends on filtration, plant mass, and species waste output.

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Neon Tetra (Paracheirodon innesi)

Low Bioload

A 10 Gallon tank can sustain 8–10 neon tetras with moderate live plants and adequate biological filtration. Their small size (~1.5 in) and low waste output make them ideal for beginner planted setups. Use the True Dosing Volume when treating for ich or columnaris.

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Fancy Goldfish (Carassius auratus)

Extreme Bioload

1 Fancy Goldfish requires a minimum of 20–30 gallons due to extreme waste production. The 1-inch-per-gallon rule does not apply to goldfish. They produce ammonia at 10× the rate of tropical species. Filter turnover must be 8×–10× tank volume per hour minimum.

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Guppies & Endlers (Poecilia reticulata)

Moderate — Breeding Alert

A 10 Gallon setup can support 5–6 guppies. However, as livebearers, a breeding colony will rapidly double the bioload within 60 days, overwhelming biological filtration. Maintain a single-sex colony or add dense floating plants (Water Sprite, Salvinia) to absorb the nitrogen spike.

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Filter Turnover Rule: Target 4×–6× tank volume per hour for low-bioload species (tetras, rasboras). For goldfish, cichlids, or aggressive breeders, target 8×–10× per hour. Calculate your filter turnover rate →