---
title: Aquarium gravel in a terrarium | Glass Jar Garden
description: Aquarium gravel: Clean grey gravel that holds almost no water. Drainage. In the jar it has holds water 7.5 % by volume, pore space 40 % by volume, weight...
url: https://glassjar.garden/guide/soils/aquarium-gravel/
---

Soils and layers

# Aquarium gravel
Reusable

Clean grey gravel that holds almost no water. Drainage.

## What the simulation uses

- Holds water: 7.5 % by volume (Water it keeps after draining; the rest runs down to the drainage.)

- Pore space: 40 % by volume (Room for air and water between grains; low means roots suffocate when wet.)

- Weight: 1500 g/L (How heavy a litre is.)

- pH: 6.5 to 7.5 pH (How acid it keeps the soil.)

- Mould risk: none (How much fresh food it gives white mould; high-risk soils fuzz over in the first weeks.)

- Nutrients: none (Plant food it brings.)

- Presses down to: 97 % of its loose depth (How far pressing can pack it, keeping its weight.)

## Description
Washed gravel from pea-sized down to a millimetre or two, with no nutrients and no effect on pH. Finer grades wick slightly more water up. Unsure whether a bag is lime-free? A drop of vinegar fizzes on limestone.

Also called fish tank gravel, quartz gravel.

Estimated, where sources were thin: porosity and water holding estimated from packing; coated/coloured gravel not characterised.

## Sources

- [en.wikipedia.org/wiki/Substrate_(aquarium)](https://en.wikipedia.org/wiki/Substrate_(aquarium))
- [engineeringtoolbox.com/density-materials-d_1652.html](https://www.engineeringtoolbox.com/density-materials-d_1652.html)
- [en.wikipedia.org/wiki/Bulk_density](https://en.wikipedia.org/wiki/Bulk_density)

[Grow it in a jar](https://glassjar.garden/?guide=soils/aquarium-gravel)

[Akadama](https://glassjar.garden/guide/soils/akadama/) · [Aquarium sand](https://glassjar.garden/guide/soils/aquarium-sand/) · [All soils and layers](https://glassjar.garden/guide/soils/)