Growool is water absorbent rockwool made in USA and is used as a soiless growing medium. Growool consists of a mat of long, fine fibres, spun from natural molten rock. This mat is cut and shaped by Growool Horticultural Systems into the individual Growool products. When using the Growool system there is potential for greater control over plant growth and yield. These potential advantages are only realized with very good management and attention to detail. Soiless systems do not guarantee success. They require better management than soil based systems. Your system must be set up carefully and then monitored closely and accurately. Plants and nutrient solutions must be checked carefully and regularly.

Properties of Growool has a unique combination of properties which make it an excellent growing medium. These properties need to be considered if the material is to be used to its maximum effectiveness:

• Its rigid shape makes it very easy to handle.
• It is inorganic and inert ie contains no nutrient.
• It has no cation exchange capacity ie it won't bind nutrients.
• It has no pH buffer of water or liquid feed.
• It is a natural rock and is not biodegradable.
• It has very high water and air holding capacity, typically 80% water plus 17% air. This is influenced by the height of the growool and the drainage characteristics of the surface upon which it stands. The deeper the slab the better it drains and Growool should always be able to drain freely.