4 4" Rockwool cubes (100mm)
Popular for use in NFT Systems, placed directly onto the plant tray / spreader mat.

Rockwool slabs (more popular in Holland than the UK) 4" cubes are placed onto rockwool slabs wrapped in plastic and each plant staked with a dripper.

Ideal for all sorts of plant crops - for example tomatoes, cucumbers, peppers, herbs, flowers and orchids - in indoor, outdoor and glasshouse environments.

Using Rockwool

Before using rockwool it is best soaked in pH adjusted water: a couple of drops of pH down acid and test the pH, repeat until the water has a pH of 5.5-6.0. Small amounts of nutrients & additives eg root stimulators can also be added to the mix in which the cubes are soaked.

How do I water my plants?

Either automatically or by hand, if you need advice please feel free to call us. Some pointers here
- add food to your water for every watering, this is the only way your plants will get the nutrients they need.
- use a quality hydroponic nutrient.
- lift pots to feel the weight, when they feel light it is time to water them.
- add nutrient water until 25% of what you put in drains away, ensuring replenishment with fresh food.
- allow your plant to drain well.

The benefits of growing with rockwool

Cultivating plants hydroponically is an easy and environmentally sound way to grow a wide variety of healthy plants. Some of the benefits over soil include...
- very light, cheap to transport and easy to carry home.
- 100% natural, inert and sterile. A clean start with reduced risk of contamination from soil born diseases. Little or no pesticides required.
- plant growth up to 50% faster because of the ideal access to food and water.
- higher yields and better quality due to optimum air:water balance in the root zone.
- inert and therefore easy to control EC and pH.
- the absense of a buffer in the growing medium means that the nutrients are easily available to the plant (they do not remain 'bound up' as occurs in buffered mediums like peat moss or coco fibre).
- you can use smaller containers and grow more plants per m2, and the roots can grow throughout the media without the negative effects of being rootbound.

Rockwool may not be the most pleasant material to the touch, and its not biodegrable, but it is however recyclable.

Some helpful pointers on rockwool...

For short cycle plants, e.g. annuals and herbs, 4" cubes often go straight into a hydroponics system, directly, for example in an NFT system. Cubes are manufactured with ‘grooves’ on the bottom to assist aeration. In some systems, eg NFT, the cube is ideally positioned in such a way as to allow the grooves to assist the nutrient solution to pass through the cube, rather than creating a barricade or dam effect pushing the nutrient flow around the block. The sleeve in which the cubes are provided is typically left on the block. The sleeve is useful for blocking light from the side of your cube and helping to concentrate root development down to the bottom of the cube.

Rockwool products are made from basalt rocks and chalk, which come from the earth. Mimicking Mother Nature's production of 'angel hair' during volcanic activity rockwool is manufactured by heating rocks to 1600C, to create lava. The lava is blown into a spinning chamber, which makes fibres similar to candy-floss. The fibres are packed into mats and then cut to shape and size. One cubic metre of rock becomes 37 cubic metres of rockwool.