Rockwool Hydroponics

You want to use rockwool for your next hydroponics? Rockwool hydrophonics is an extremely popular growing medium for hydroponics. The word hydroponics comes from the Latin that means working water, can be simply interpreted as the art of growing plants without the use of soil.

Yes, hydroponics still need material as a growing medium in which the roots of the plant are growing, its aerate and support the root system of the plant and to channel the water and nutrients.

There are many varieties of a medium which include rockwool, perlite, vermiculite, coconut fiber, gravel, sand and many more. Usually for hydroponics, rockwool is use for starting seeds.

Read more: What is a Hydroponic Farm

What is Rockwool Made Of

Rockwool was originally used in construction as insulation. Rockwool made from a combination of chalk and rock that heated up to around 3,000 degrees Fahrenheit. Then use a stream of air to blown through it, resulting in extremely thin fibers of the rocky material. As the strings are blown out, they formed together and becoming what we know as rockwool.

Rockwool Dimensions

For hydroponics, manufacturers made a horticultural grade of Rockwool. Unlike the insulation grade, horticultural rockwool is pressed into growing cubes, plugs, blocks and sheets. This is few of rockwool dimension and distributors:

Rockwool Cubes, dimensions 1″ x 1″

Rockwool Plugs, dimensions 1,5″ x 2,5″

Rockwool Plugs
Rockwool Plugs

Rockwool Sheets, dimensions 1″x1″ of 200 Rockwool

Rockwool Cube
Rockwool Sheets

Rockwool Blocks, dimensions 4″ x 4″ x 2,5″

Rockwool Blocks
Rockwool Blocks

Why Rockwool


– Easy to use

– Easy to buy, almost in every hydroponics stores near you

–  It can be used in just about any hydroponic system

– Retain lots of water. Its holds 10-14 times as much water as soil and retains 20 percent air


–  Rockwool fibers and dust can be harmful to eyes, nose, and lungs.

– Not environment-friendly. It took a very long time to decay

Rockwool has been around for decades and is well-known in the hydroponic growing community. It has all of the benefits of most growing media, with some pretty serious downsides. Yes, you still can choose to use rockwool for your next hydroponics journey, or you can use alternatives growing media as coconut fiber, perlite, sand and other hydroponics growing medium.