Rockwool is a type of lightweight mineral fiber product made from basic rock materials and designed as a silencer material, insulation against heat, and can also be used as a hydroponic growing medium. The general function of rockwool is to provide insulation in residential or commercial buildings. Rockwool is also used as a growing medium for horticulture.
There are 2 types of rockwool as a hydroponic media, specifically agricultural rockwool and rockwool insulator. Rockwool insulators are usually used for air conditioning (AC) or hot water in a multi-storey building. Rockwool that is now widely used by hydroponic hobbyists.