Substrate type guide
Aquarium substrate types and density
The same volume can weigh differently depending on whether you use sand, gravel, or aqua soil.
Why aquarium sand, gravel, and aqua soil can need different bag counts for the same tank footprint and depth.
Volume is not the same as weight
The calculator first estimates litres, then converts litres to weight using the density you enter.
- Sand and gravel are often heavier per litre than aqua soil.
- Bag counts change when density or bag size changes.
- Use supplier data where available instead of a generic estimate.
Why bag counts vary
Different brands pack and label substrate by weight, volume, or both, so the bag count can change even for the same tank.
- Check the label for kg, litres, or coverage notes.
- Use the calculator to compare options consistently.
- Round up when running short would delay the setup.
Substrate depth depends on livestock, plants, and tank design. Check species-specific requirements.