Grodan Rockwool is a mineral wool made from molten basalt and limestone rock that is spun into cotton-candy like fibres and then compressed into cubes, blocks or slabs. Being made from natural rock, Grodan is a mineral based product used in hydroponic growing applications.
The WCB or Wrapped Crop Box Slab by GRODAN is designed to suit a 45litre crop box crate. They are called wrapped as they are supplied as individually plastic wrapped slabs and the wrapping is UV resistant. Featuring a predominantly horizontal fibre structure which allows for slow water movement through fibres, these slabs are best used where less frequent watering is required or in hot climates. These slabs are an ideal multi-year (2 year) slab.
To use, cut a hole or holes in the plastic to the size of the rockwool cube that you want to use with the slab. Fill the slab with water to moisten the rockwool, then flip the slab over and cut drainage slits in the bottom of the plastic across the width. Flip the slab back over and place your planted growing cubes on the previously cut-out holes in the top side of the slab. The plant roots will then grow through to the slab over time.