---
title: Limestone in a terrarium | Glass Jar Garden
description: Limestone: Pale stone that slowly makes the soil less acid. In the jar it has holds water 7.5 % by volume, pore space 20.05 % by volume, weight 1440 g/L.
url: https://glassjar.garden/guide/hardscape/limestone/
---

Stones and wood

# Limestone
Reusable

Pale stone that slowly makes the soil less acid.

## What the simulation uses

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

- Pore space: 20.05 % 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: 7.5 to 9 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.)

## Description
Calcium-rich rock that neutralises acid, steadily pushing up the pH and hardness of nearby soil and water. That makes it a poor match for acid-loving mosses. A drop of vinegar fizzes on it, an easy way to spot it.

Also called calcite rock, Texas holey rock.

Estimated, where sources were thin: rate of pH/KH rise in a terrarium unquantified.

## Sources

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

[Grow it in a jar](https://glassjar.garden/?guide=hardscape/limestone)

[Horn wood](https://glassjar.garden/guide/hardscape/horn-wood/) · [Manten stone](https://glassjar.garden/guide/hardscape/manten-stone/) · [All stones and wood](https://glassjar.garden/guide/hardscape/)