Expanded Shale is a lightweight aggregate that is an ideal growing media in hydroponic or aquaponic systems. The shale is mined, crushed and fired under high temperatures in a rotary kiln, producing a clean, inert, porous, and light material.
Because of the large amount of cracks and fissures in the expanded, the media can retain a large amount of moisture which can reduce the amount of flooding cycles needed for flood & drain (ebb & flow) systems.
For aquaponic systems, there is a large amount of surface area per stone for producing beneficial bacteria for converting ammonia into nitrates.
Expanded shale has been used for nearly 100 years primarily as a building material. It is added to concrete to make lighter buildings and bridges since it is half the weight of standard crushed stone. The aggregate is also used as an additive in clay soils to increase its drainage properties as well as a decorative mulch around buildings and gardens.
Shipped in a double walled box with two inner bag liners to prevent spilling.