---
title: Black sand in a terrarium | Glass Jar Garden
description: Black sand: Fine black sand that makes paths and contrast pop. In the jar it has holds water 23 % by volume, pore space 38.5 % by volume, weight 1550 g/L.
url: https://glassjar.garden/guide/soils/black-sand/
---

Soils and layers

# Black sand

Fine black sand that makes paths and contrast pop.

## What the simulation uses

- Holds water: 23 % by volume (Water it keeps after draining; the rest runs down to the drainage.)

- Pore space: 38.5 % by volume (Room for air and water between grains; low means roots suffocate when wet.)

- Weight: 1550 g/L (How heavy a litre is.)

- pH: 6.8 to 7.2 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: low (Plant food it brings.)

- Presses down to: 88 % of its loose depth (How far pressing can pack it, keeping its weight.)

## Description
Fine black sand that makes paths and contrast pop. It holds a little water and changes nothing about the soil.

Also called black aquarium sand.

Estimated, where sources were thin: values estimated from hobby and horticultural references; not measured.

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

[Biochar](https://glassjar.garden/guide/soils/biochar/) · [Calcined clay](https://glassjar.garden/guide/soils/calcined-clay/) · [All soils and layers](https://glassjar.garden/guide/soils/)