---
title: Pea gravel in a terrarium | Glass Jar Garden
description: Pea gravel: Round, smooth gravel that holds no water. Drainage. In the jar it has holds water 5 % by volume, pore space 40 % by volume, weight 1450 g/L.
url: https://glassjar.garden/guide/soils/pea-gravel/
---

Soils and layers

# Pea gravel
Reusable

Round, smooth gravel that holds no water. Drainage.

## What the simulation uses

- Holds water: 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: 1450 g/L (How heavy a litre is.)

- pH: 6.5 to 8 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
Rounded natural stones of five to ten millimetres. Water runs straight through, though the gaps can hold a small reservoir at the bottom. It is very heavy for its volume, and some gravels contain lime that raises pH.

Also called pea shingle.

Estimated, where sources were thin: porosity_pct; water_holding_pct_by_vol; air_filled_porosity_pct measured values not found; packing-theory estimates.

## Sources

- [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)
- [en.wikipedia.org/wiki/Substrate_(aquarium)](https://en.wikipedia.org/wiki/Substrate_(aquarium))

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

[Orchid bark (fir/pine bark)](https://glassjar.garden/guide/soils/orchid-bark/) · [Peat-based soilless mix](https://glassjar.garden/guide/soils/peat-based-mix/) · [All soils and layers](https://glassjar.garden/guide/soils/)