Coco Coir VS Rockwool

The majority of expert growers consider the properties of the substrate to make the best decision for their growing needs. In this article, we’ll examine two substrates, coco coir and rockwool, and compare their benefits and drawbacks so that you, the grower, may decide which is best before spending your time and money on them.

In hydroponic growing systems, gardeners most frequently employ coco coir and rockwool as substrates. And with good reason. Both provide the characteristics that hydroponic growers require, including simple fertiliser and pH control and efficient root zone aeration.

However, no two substrates or growth environments are exactly alike. 

Coco Coir:

Growers are using coco coir as their preferred substrate more and more. In addition to hydroponics, coco coir may be used in almost every growing environment, such as in the field, your backyard garden, and the creation of potted plants. 

Manufacturers like Atlantis Coco convert coconut husks—which would otherwise go to waste—into coco coir. We harvest the husks and compress them into bundles for shipping. The majority of the coco coir used in horticulture originates from India.

For a variety of reasons, lovers of coco coir adore the substrate. It’s also an accessible method for the beginner grower. The pH of coco coir varies between 5.5 and 6.5, so, like any growing medium, you must closely monitor and make adjustments accordingly.

The fact that coco coir is a sustainable commodity appeals to both consumers and producers. Like any organic material, coco coir decomposes in the environment with ease. Additionally, coco coir can occasionally be recycled or composted.

Due to the cation exchange capacity of coco fibre, some of the minerals, most notably calcium and magnesium, won’t be accessible to the plant. A calcium and magnesium supplement meal may be necessary in this situation.


Hydroponics and rockwool are basically interchangeable terms. It is made from basalt rock, a volcanic substance. Manufacturers spin the substance into fibres after heating it to the point of molten lava. An inorganic substrate that doesn’t degrade in the environment like plant-based substrates is the end product. 

Some producers value Rockwool’s dependability and simplicity of usage. Additionally, Rockwool is a sturdy substrate that won’t degrade during the crop cycle, as we’ve already said. It can be used to cultivate the majority of vegetables, herbs, and flowers hydroponic systems.

Rockwool is an inert substrate devoid of nutrients, similar to coco coir. As a result, it is simple to control the environment around the plant’s root system. You may easily make adjustments if you run into issues during the crop cycle, such as an increase in pH or a nutrient shortage.

Rockwool is not obtained sustainably, unlike coco coir, and it does not decompose in the environment. Long-term exposure to Rockwool raises questions regarding product safety, while the available evidence isn’t definitive. You should still err on the side of caution since you don’t want to hurt yourself, your staff, or even worse, the actual customer.


The two media that hydroponic producers most frequently use are coco coir and rockwool. Because it may be used in home gardens and other non-hydroponic growth environments, coco coir is more adaptable. Both media are easily accessible and give plants’ roots adequate aeration. While Coco Coir is a sustainable product made from coconut waste, manufacturers extract rockwool from non-renewable sources.

In the end, it is up to you, the grower, to decide which substrate is best for your growing environment. Whatever substrate you decide on, make sure to pick a trustworthy supplier that will offer a consistent product from slab to slab or bale to bale.

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