What is Rockwool?

Written by James Puno

December 17, 2019

Also known as “Mineral Insulation”, Rockwool was once used for the purpose of lowering down the temperature.  Made from melted rock and sand, this type of growing medium will surely satisfy as an alternative media in soilless culture. Rockwool comes in various shapes and sizes depending on the purpose of the grower. Commercial gardens usually use the 3” x 12” x 36” slabs while small time growers resort to buying 1” x 1” starter cubes.

As a grower, you can expect Rockwool as a type of growing medium that can hold water for a long period of time. Fruits and vegetables that are planted on either hydroponic or aquaponic systems suffer from power outages. Using such growing medium though will protect the roots from drying up in case the pump goes off. Another advantage you can get from using Rockwool is its ability to retain 18% air at all times. Growing mediums should be able to supply oxygen to the roots for proper growth and nourishment.

Unlike with most growing mediums though, Rockwool presents several disadvantages. Handling Rockwool can be quite risky as its dust and fibers are hazardous to your health. You need to wear protective gears such as face mask, eye goggles, and hand gloves whenever you handle the media. You also need to consistently check the pH level of the water as Rockwool has some issues in terms of pH level.

Rockwool used in either an aquaponic or hydroponic system will bring great results to the grower. In most cases, faster plant growth can be attributed to the growing medium.

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