Inert Grow Medium

Last updated: May 13, 2021

What Does Inert Grow Medium Mean?

An inert grow medium is a type of grow media that contains no nutrients.

In general, a good grow medium ensures that plant roots have a place to anchor and retains moisture at the same time. Some types of grow medium, such as potting mixes and soil, come pre-charged with nutrients and amendments in many cases. These would be considered the opposite of an inert medium.

Because the medium is inert, the grower can more easily control the nutrient and water supply and ratios that the plant receives. The inertness of the medium also allows the grower to maintain the pH level around the plant’s roots.

Growing using an inert grow medium is an important consideration for both hydroponic systems and aquaponics systems. Inert grow media is widely used for cannabis cultivation, but it is also used to grow a bevy of other types of vegetables and crops.


Maximum Yield Explains Inert Grow Medium

In hydroponic and aquaponics systems, plants are grown without soil. However, plants still need something in which to anchor their roots, and something to support them during growth. An inert grow medium is used for this purpose, as well as to retain moisture to help foster healthier plants.

Unlike soil, inert grow mediums do not decay or compost. Some types can even be reused if they are sterilized in between each growth cycle.

There are quite a few different options available when it comes to choosing an inert grow medium. One of the most popular is rockwool. This is made from actual stone, which is melted and then spun into fibers, similar to steel wool. However, rockwool is not 100% biodegradable, so it may not be the right option for you.

Another popular choice is LECA, or lightweight expanded clay aggregate. Generally found in the form of pebbles, these are made from 100% organic clay. They do not biodegrade, and can provide a permanent grow medium for your plants. LECA pebbles contain tiny capillaries that retain moisture very well for long periods of time.

Coir, or coco fiber is another popular solution. While it is organic in nature (it’s made from coconut husks), it is inert in that it does not contain any harmful microbes, nor does it supply plants with any nutrients. However, it does break down over time, and it naturally resists mold and fungus.

Perlite is another inter grow medium that many growers turn to, particularly for starting from seeds or new cuttings. Perlite pebbles are very small, and are chemically inert. However, they may float if flooded, and are not ideal for mature plants.

All of the mediums used are light and porous, which allows the marijuana plant’s root system to receive the maximum oxygenation that it requires to grow. The inert grow medium also supplies optimal support to the cannabis plant’s roots, stalk, and foliage.

You’ll find numerous other options available, as well, including vermiculite, sand, gravel, and more.

Inert grow mediums are considered soilless mixes, or soilless media. Some types require soaking, washing, or pH balancing before their first use, which enables a plant to easily put down roots. Inert grow media is sometimes also referred to as hydroponic grow media because they require the addition of hydroponic nutrients.



Inert Grow Media

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