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 medium, namely rockwool specifically for agriculture and rockwool insulator. Rockwool insulator is usually used for air conditioning (AC) or hot water tubes in multi-storey buildings. Rockwool is now widely used by hydroponic hobbyists.