How to Recycle Rockwool

Rockwool is one of most popular grow media in hydroponics. It's a naturally occurring product that is often used to situate plant roots for different kinds of systems including deep water culture, ebb and flow, or tray table systems. It's not something that's obscure in the hydroponics world.

With that in mind, it can be helpful to think about how to use rockwool more than just one time. You might get this material in slabs or in pieces from a manufacturer. It's often shipped to the grower's home or business address. Use it for a plant cycle, and then you wonder whether you should get rid of it or use it again.

Here are some steps to effectively recycling rockwool.

Disassemble and clean the grow space

This step should not be skipped. Before you try to do anything with rockwool, you have to go in and get all of the dead plant debris out of the space. Take individual rockwool pieces out and discard any material that's clinging to them. Clean and wash plant pots and other pieces of the system. Then you can start getting your hands dirty with figuring out how to recycle rockwool.

Take out any roots in the rockwool

You'll also want to effectively separate any excess root material and the actual rockwool pieces. Getting all of this biological material out to benefit from a cleaned and organized grow area.

Steam clean rockwool

That's right, the recycling process for rockwool works on the same basis as your steam cleaning Shark or other hot water powered tool for your kitchen floors. Experts recommend steaming the rockwool at a temperature that reaches 212°F. Those offering ‘hydroponic hacks’ sometimes recommend items like a wallpaper steamer that you can get for rent at your local supermarket.

Assess the condition of rockwool

Over time, as you recycle this stuff, it will tend to break down a little bit. At some point, you can actually crumble up the rockwool and recycle it again. You’ll do this the same way -- by steaming.

Eventually, some growers combine rockwool with other materials for other uses.

Find other uses

Rockwool is also an effective insulator. That's another way to use this substance if you have a lot of it in blocks.

For more on what to do with various types of hydroponic grow media, as well as how to select lights, nutrients and other pieces for hydroponics setups, take a look at our Dealzer website. We help beginning growers to understand how to outfit themselves for success. We want you to get the most out of the equipment that you bought, so keep an eye on our blogs and other pages as you put together a hydro garden.