4 Best Growing Media for Hydroponics

So, you've probably already read the article "Hydroponics for Beginners" and it's clear to you that hydroponics is the best choice for indoor growing. However, since hydroponics doesn't use traditional growing substrate, you need to select the best possible growing medium. But where to start and what criteria should you use? The basic parameters you'll be choosing by are the ability to retain moisture, aeration, and pH neutrality. Let's describe the 4 most commonly used growing media for hydroponic cultivation.

1. Coconut Fiber

One of the most natural types of growing medium is coconut fiber from coconut husk. Just as in nature, coconut husk protects the coconut seed from solar radiation and the adverse effects of salt water, it can also help your plant seedlings - it increases resistance against harmful fungi. Moreover, coconut fiber medium has an excellent water/air ratio - it can hold large amounts of water while maintaining sufficient airiness throughout the medium.

However, since coconut fiber has high water retention, it's not recommended for ebb & flow hydroponic systems, but it's perfect for drip systems.

2. Rock Wool Growing Cubes

Growing cubes are made from fibrous material produced from molten rock. The manufacturing process creates a fibrous medium that is a very popular choice for growing medium, especially for germination and hydroponics. Like coconut fiber, it can hold large amounts of water while maintaining sufficient airiness throughout the medium. Before use, it's always recommended to balance the pH by soaking in pre-adjusted water.

It's particularly suitable for drip and wick hydroponic systems.

3. Expanded Clay

Expanded clay is undoubtedly one of the most popular growing media, and it's no wonder - expanded clay has a neutral pH, can be used over and over again, has fast drainage, and moreover, no excess substances and components leach from it into the nutrient solution, so your nutrient solution stays nice and clean. The individual pieces of expanded clay leave enough space between them for healthy development of the plant root system. They are ideal for use in ebb&flow type hydroponic systems. For better water retention, a 50:50 coco/expanded clay mix works very well.

4. Vermiculite/Perlite Soil Mix

Some hydroponic growers prefer a mix of vermiculite or coconut fiber and perlite. Vermiculite and perlite are excellent aids for hydroponic growing - their properties are very similar to coconut fibers. However, when using perlite and vermiculite, it is recommended to emphasize the filtration system - the particles should not come into contact with the nutrient solution.