What is Rockwool?

rockwool is an excellent substrate for hydroponic greenhouses. From cubes for head lettuce to full 10×20 sheets for micro-greens, there are tons of applications for this amazing material.

While working with a customer, I was recently asked what rockwool is and where it comes from. I wanted to share my findings with the community because the process is quite amazing.

Stone wool substrates are made from basalt rock, which is processed at a very high temperature (over 2,900ºF!). Essentially, the companies that create rock wool are creating volcanic conditions within a factory.

These are what the rocks look like before the process:

Rockwool is manufactured by melting these basaltic rocks and spinning the melt into fibers.

This diagram shows the process in more detail:

Rockwool has multiple applications, including insulation and brake pads, however I will be focusing on its use as a hydroponic substrate.

I look forward to informing the community on the many benefits of Grodan Rockwool in hydroponic operations; it is by far the most promising substrate I have used.

My next entry will be The many benefits of Rockwool as a Growing Substrate for Hydroponic Systems. Keep on growing!

Let me know your thoughts, Thank you!

All my best,