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.