Aquarium Gravel & Substrate Calculator
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Aquarium Gravel & Substrate Calculator
Calculate the required amount of substrate for different aquarium shapes.
How much gravel or soil does my aquarium need?
Why is substrate depth important?
The right amount of substrate is crucial for a healthy planted aquarium. Too little substrate limits root development and nutrient availability, while too much wastes money and reduces swimming space. For planted tanks, a proper substrate layer provides anchorage, nutrient storage, and beneficial bacteria colonization.
Recommended substrate depths
- Decorative only (no plants): 2–3 cm – Just enough to cover the glass and anchor decorations
- Easy plants: 4–5 cm – Sufficient for Anubias, Java Fern, Cryptocoryne, and similar plants
- Demanding plants: 5–8 cm – Required for heavy root feeders like Echinodorus, Vallisneria, and carpet plants
- Aquascaping: 3–12 cm (sloped) – Higher in back, lower in front for visual depth
Common substrate types and their densities
| Substrate type | Density (kg/L) | Best for |
|---|---|---|
| Aqua soil (ADA, Tropica, etc.) | 0.8–1.0 | Heavily planted tanks |
| Fine sand | 1.5–1.7 | Corydoras, loaches |
| Gravel (2–5 mm) | 1.4–1.6 | General purpose |
| Lava rock granules | 0.8–1.2 | Bacteria colonization |
The formula for substrate calculation
Rectangular: Volume (L) = Length × Width × Depth ÷ 1000 | Weight (kg) = Volume × Density
Tips for substrate setup
- Create a slope from back to front (higher in rear) to add visual depth and help debris collect at the front for easier cleaning
- For planted tanks, consider layering: nutrient-rich substrate or fertilizer base at bottom, capped with gravel or sand
- Always rinse inert substrates (sand, gravel) thoroughly before adding to prevent cloudiness
- Buy 10–15%% extra substrate – you will lose some during maintenance and rescaping