All growers looking to set up a hydroponic system are confronted with the same looming question: what grow medium should I use? It is important to consider the type of hydroponic system the grower plans on using as some media are more compatible with certain systems than others. Before a grower makes his or her final decision, the advantages and disadvantages of each medium should be examined to see which best fits the grower’s needs. The most commonly used hydroponic media are: stonewool (Rockwool), expanded clay pebbles, coconut fiber, and perlite.

Stonewool (Rockwool)

Stonewool is one of the most popular hydroponic media for growers of high-value plants. It is made from spun basalt rock and has amazing water retaining properties. Stonewool can be used in all stages of growth, including propagation. Stonewool is available in cubes, slabs, bails, and flocked (loose) which makes it compatible with many different types of hydroponic systems. A few of the advantages of stonewool are its high compatibility with various hydroponic systems, its high water retention ability, and its light weight (which makes logistics much simpler for the urban gardener). Some of the disadvantages of stonewool are its need to be conditioned before use and disposing of it after the plants are harvested.

Expanded Clay Pebbles

Expanded clay pebbles, or hydroton, are probably the most identifiable hydroponic medium. Expanded clay is an inert medium that holds a lot of air and still retains some moisture. Its ability to hold oxygen facilitates root growth and is a huge advantage to the grower of high-value plants. Expanded clay can be used as both the medium for the root zone and as a stabilizer in systems where the root zone is mainly suspended in water or air (deep water culture, aeroponics, etc). Disadvantages of clay pebbles are they are heavy, they are dusty (need to be rinsed completely before use), and in some hydroponic systems they can dry out too quickly.

Coconut Fiber

Coconut fiber has quickly gained popularity as a hydroponic medium. Coconut fiber is made from ground coconut husks and is a byproduct of the coconut industry. Coconut fiber has the amazing ability to retain both moisture and oxygen simultaneously. This is a huge advantage to the grower of high-value plants because it allows for the conditions needed for maximum nutrient absorption. Unfortunately, coconut fiber is not perfect. Unless it is rinsed thoroughly, coconut fiber can contain salts that could affect performance. Coconut fiber also has a tendency to hold magnesium and calcium. This is why plant nutrition needs to be slightly adjusted when using coconut fiber.

Perlite

Perlite is a high oxygen hydroponic medium. Although it can be used by itself, perlite is usually mixed with another medium to increase water retention. Advantages of perlite are its low cost, light weight, and availability. Perlite floats which makes it difficult to use in some hydroponic systems. Perlite dust is harmful when breathed so extra caution must be used when handling.

Growers looking to take advantage of hydroponic growing should research each of the different media before making a final decision. Experimentation is the best way to test a few of the different hydroponic media to see which performs best in your hydroponic system.

© Copyright RosebudMag.com, 2013