Is Rockwool Harmful? Yes, But…

Ed Wike
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It’s Not Environmentally Friendly

When I first heard that rockwool is harmful, I was surprised. I was under the impression that it was completely benign.

I mean, after all, rockwool is a by-product of the mining industry. It’s used to make cement and other items like brake pads. Rockwool is used in fish farms, and it’s the product of choice for hydroponics.

But then I started digging. The problem with rockwool is that it’s made by heating rock and minerals. Its potential carbon footprint rivals or betters that of wood, per unit weight.

It comes from somewhere, and even though its origins don’t completely negate the environmentally friendly aspects of using rockwool, it puts a sizable dent in its already problematic environmental impact.

It’s Not Healthy To Be Around

Rockwool was invented over 60 years ago, with the purpose of replacing mineral wool used in the construction of buildings. It is made from molten basaltic rock that is spun into fibers that can be knit into the fabric. This material has a hardness of 90 on the Moh scale and is completely non-porous compared to regular glass and plastic.

It’s also used for insulation, in shower panels, and various types of cement.

Rockwool is made by melting the rocks and spinning them until they are either in fibers or strands of consistent width that resemble a rope.

When the rockwool was invented, no one took into account its effects on the environment or on humans. The intention was for it to be asbestos free, and never contain minerals, and even with that it still has a high concentration of minerals that have been shown to be harmful. It has also been tested, and found to be radioactive at times.

Rockwool has been found to release dust and microscopic fibers into the air that a human could inhale and these fibers are extremely small and could cause lung disease and other issues. These particles can also make their way into the oceans and oceans where they dissolve easily and can be inhaled by marine animals.

It Has a Naturally High pH

Rockwool. A lot of people are not really fond of it because of the way it looks, but is it harmful? Do Rockwool sheets contain harmful chemicals?

Rockwool right from the square bales can have a pH of 11 and it was developed in Norway in 1891. Gotabaya National Institute for Horticultural Research in Sri Lanka found turface carries a high level of boron. This is an addictive substance that is known to cause Alzheimer’s disease in men.

Even using indoor nutrient lines to fertilize your plant, the nutrient solution can be up to 7.0 which is 15 times the recommended level. Greenhouse growers use rockwool for the same reason the do to grow cannabis and marijuana and it’s the best growing media on the market now.

In the eighties the government banned it in vegatative growing because of the boron, but they learned that you need to do a pH spike in the early stages of the vegatative state but in the flowering stage a spike would be fatal. Therefore they decided that it is not harmful but they do recommend that if you don’t know how to use it properly that you shouldn’t use it at all.