---
title: Horticultural sand in a terrarium | Glass Jar Garden
description: Horticultural sand: Coarse washed sand that opens soil and drains fast. In the jar it has holds water 10 % by volume, pore space 40 % by volume, weight 1440...
url: https://glassjar.garden/guide/soils/horticultural-sand/
---

Soils and layers

# Horticultural sand
Reusable

Coarse washed sand that opens soil and drains fast.

## What the simulation uses

- Holds water: 10 % 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: 1440 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: 72 % of its loose depth (How far pressing can pack it, keeping its weight.)

## Description
Washed silica grains up to two millimetres across, heavy and free of nutrients. It suits arid mixes that need weight and drainage. Stirred into fine organic soil it can fill the air gaps instead, so keep the rest of the mix coarse.

Also called sharp sand, grit.

Estimated, where sources were thin: porosity/water values estimated from sand soil literature.

## Sources

- [engineeringtoolbox.com/density-materials-d_1652.html](https://www.engineeringtoolbox.com/density-materials-d_1652.html)
- [engineeringtoolbox.com/density-solids-d_1265.html](https://www.engineeringtoolbox.com/density-solids-d_1265.html)
- [en.wikipedia.org/wiki/Bulk_density](https://en.wikipedia.org/wiki/Bulk_density)

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

[Horticultural charcoal](https://glassjar.garden/guide/soils/horticultural-charcoal/) · [Lava rock (scoria)](https://glassjar.garden/guide/soils/lava-rock/) · [All soils and layers](https://glassjar.garden/guide/soils/)