Table 1.

Typical physical characteristics of common inorganic and organic hydroponic growing media [9].

Medium	Bulk Density (g/cm3)	Pore Volume (% by Volume)
Sand (0.02–2.0 mm particles)	1.48–1.80	30–45
Perlite	0.4–0.7	70–85
Rockwool	0.05–0.2	92–98
Sphagnum-based peats	41–263	84–96
Coconut coir	40–89	86–96