Grodan Granulate is an ultra-clean, sterile substrate for hydroponic production. Made from molten basalt and limestone rock that is spun into cotton-candy like fibres and then compressed into cubes, blocks or slabs.
Granulate rockwool can be effectively used in recirculating or run-to-waste systems and has a very high water holding capacity.
Grodan Granulate is compressed into a 20kg bale, but makes around 140L of growing medium.
This product is extremely practical for using in hanging baskets, as a stand alone medium or even as a change from traditional potting mixes. The product is much cleaner to use than potting mixes, has a higher water holding capacity and can actually reduce watering houseplants to approximately once every 2 to 4 weeks.