Aquarium Substrate Calculator - Sand & Gravel

How to use

Step-by-step guide

The right amount of substrate is essential for plant growth, beneficial bacteria colonization, and aesthetic appeal. Our aquarium substrate calculator helps you determine exactly how much sand, gravel, or aqua soil you need for any tank size, from 10 gallon to 200+ gallon aquariums.

1. No. 01

   Measure tank base

   Measure the length and width of your tank's bottom. Use inside measurements for accuracy.

2. No. 02

   Choose substrate type

   Select sand, gravel, or aqua soil. Each has different densities affecting the amount needed.

3. No. 03

   Determine desired depth

   Enter your target depth. A common guideline is about 1-2 inches for fish-only tanks and 2-3 inches for planted tanks, often sloped to 3-4 inches at the back.

4. No. 04

   Calculate amount

   Get the weight in pounds, the number of bags, and the volume in cubic inches and litres. Weights use typical dry densities: about 100 lb per cubic foot for sand, 90 for gravel, and 60 for aqua soil.

Pitfalls

Common mistakes to avoid

Learn from others' errors to ensure accurate calculations and healthy aquatic life.

1. No. 01

   Using uniform depth across entire tank

   Why it matters — Flat look and shallow rooting where plants need it most

   Do this instead — In planted tanks, slope from about 2" at the front to 3-4" at the back

2. No. 02

   Not rinsing substrate before use

   Why it matters — Cloudy water for days or weeks

   Do this instead — Rinse thoroughly until water runs clear (except some plant substrates)

3. No. 03

   Buying exact calculated amount

   Why it matters — Running short due to rinsing loss and settling

   Do this instead — Keep roughly 10-15% spare, often one extra bag

4. No. 04

   Using substrate too deep for tank size

   Why it matters — Reduced swimming space and anaerobic pockets

   Do this instead — Keep substrate proportional to tank height

Next up

Setting up substrate?

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