Soils and layers
Aquarium gravel
Reusable
Clean grey gravel that holds almost no water. Drainage.
What the simulation uses
- Holds water
- 7.5 % 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
- 1500 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
- 97 % of its loose depth
- How far pressing can pack it, keeping its weight.
Description
Washed gravel from pea-sized down to a millimetre or two, with no nutrients and no effect on pH. Finer grades wick slightly more water up. Unsure whether a bag is lime-free? A drop of vinegar fizzes on limestone.
Also called fish tank gravel, quartz gravel.
Estimated, where sources were thin: porosity and water holding estimated from packing; coated/coloured gravel not characterised.