A Perfect 80% Water, 20% Air Ratio, Sterile and Ready to Use

Rockwool Cubes

Rockwool is a nice clean media which has a perfect Air:Water ratio and comes in a ready to use cube format.

Rockwool is a very popular media in NFT systems.

Lettuce and herb growers use a single 25x25x40mm cube which is sufficient to sustain the root zone of the plant from the seedling stage until maturity.

Rockwool prices are very competitive, and even though they may be slightly higher than other loose  medias, which growers use to manually fill pots, the ready to use cube format of Rockwool saves a lot of time and labour which easily recovers  any additional cost.

Tomato and other vine crop growers (e.g capsicums & cucumbers) propagate their seedlings in a 75×75 x 60mm cube or larger. Once the seedling has outgrown the cube you simply place it on top of a larger media filled slab, bag or pot and within a day the seedling has anchored itself as it expands its root system into the new host media.

Rockwool is a natural media made from a volcanic rock (basalt).  The rock is liquefied under extreme heat in special furnaces and then spun into threads and re-solidified into cube format. The production process ensures sterilty in the final product.

When hydrated, each cube has a consistent 80% Water 20% Air ratio which makes it an ideal media for hydroponics as it is difficult to over water. This prevents seedling problems such as damping off.

To use this media simply unpack it from the box, fully saturate the cubes,  place the cubes onto your propagating table, place the seed in the pre-punched hole provided on top of the cube, shower the cubes with water to wet the seeds and leave the system to irrigate by automated controller. Once the seedlings are at a reasonable size for transplanting simply separate the cubes and place them in the main growing system.

Important note – The cubes must be fully soaked prior to seeding. The cubes will never fully hydrate later on if they are not 100% soaked right through. Full submersion prior to seeding is recommended.

A range of trays are also available for holding the rockwool cubes when they are in the nursery system.

The Rockwool cube sizes available from Pure Hydroponics are as follows:

  • 25x25x40mm Cubes – Box of 6000 Cubes
  • 75x75x65mm Cubes – Box of 384 Cubes
  • Rockwool Growing Slabs – Various sizes
  • Other cube sizes are able to be ordered in if required.

Please contact Pure Hydroponics to discuss which cubes are the best for your situation.




























25x25x40mm Cubes – Slab of 80 Cubes – NZ$5.00 + GST

75x75x65mm Cubes – Per Cube – NZ$0.80 cents + GST

25x25x40mm Cubes – Box of 6000 Cubes – P.O.A

75x75x65mm Cubes – Box of 384 Cubes – P.O.A