In hydroponics, the growing medium takes the place of the dirt/soil. Not to provide nutrients, but so the roots can support the plants weight and hold it upright. Just about any inert material can be used as a growing media. Inert meaning that it cant/wont decay or break down quickly, thus providing nutrients to the plants. Hydroponic growing media is simply a soil-less material that is generally porous so it can hold the moisture and oxygen that the root system requires to grow. Non porous materials can be used as well, but using no growing medium at allwatering cycles would need to be more frequent so the roots don?t dry out between watering?s. See the List of different types of growing media for hydroponics
The growing medium won?t be able to grow anything on its own. If you placed plants in hydroponic growing media, and watered it with plain water, the plants would starve from nutrient deficiency. It?s simply there to help support the plants weight as well as the moisture and oxygen the roots need. The nutrients the plants need are provided by the nutrient solution, and is what the growing media is watered and moistened with.
Some of the most widely used growing media?s include Rockwool, Lightweight Expanded Clay Aggregate (called, Hydrocorn or Grow Rock), Coconut Fiber/Coconut chips, and Perlite or Vermiculite. While there are a lot of materials that can be used as growing media in hydroponics, they can all have very different property?s than another type of media. We have even seen the use of hay bales as growing medium to grow tomatoes, using a drip lines on top to drip the nutrient solution onto the hay bales and tomato plant roots.
There isn?t one growing media that is better than the rest. Especially with so many different hydroponic system designs possible. However many growers eventually favor one type over others. There are a lot of things to consider when choosing what to use as a growing media. The type of system your growing in, and how you design and build that system is the biggest factor.
While there is no one best growing media for all situations, some growing media?s work better than others in different systems. With any hydroponic system, and/or any type of growing media, the goal is still the same. You just need the roots to be moist, not soggy and saturated. If the growing media is saturated and soggy, the roots will suffocate from lack of oxygen. That situation can easily lead to roots dying, and root rot
The Importance Of Choosing The Right Growing Medium For Hydroponics
Many types of media can be used for growing plants. For example, you?re probably already familiar with peat moss.
Growing media used in hydroponics include inorganic substances like sand, gravel, and growstones made of recycled glass, organic materials such as pine bark and coconut fiber, and even air.
When you are choosing which medium to use for your hydroponic project, you?ll need to consider factors ranging from the types of plants you intend to grow to the costs and availability of the different media. However, the main factor will be the type of system you decide to build, along with its design.
Even though the hydroponic systems and media you can use are all very different, the goal is always the same: you want the plant roots to have moisture, but not too much. If the medium is constantly saturated with water, the roots can suffocate from lack of oxygen, leading to root rot that will kill the plant.
different types of growing media for hydroponics
Rockwool
rockwool hydroponic growing mediumRockwool is one of the most common growing media?s used in hydroponics. Rockwool is a sterile, porous, non degradable medium that is composed primarily of granite and/or limestone which is super heated and melted, then spun into a small threads like cotton candy. The rockwool is then formed into blocks, sheets, cubes, slabs, or flocking. Rockwool sucks up water easily so you?ll want to be careful not to let it become saturated, or it could suffocate your plants roots, as well as lead to stem rot and root rot. Rockwool should be pH balanced before use. That?s done by soaking it in pH balanced water before use.
Pros:
Of the nutrient solution applied to rock wool, 98 percent is available to the plant.
The open pore structure leaves room for roots to grow.
Rock wool does not leach minerals into your nutrient solution.
Cons:
Rock wool must be sterilized before each successive use, and it eventually loses its structure.
It?s not biodegradable.
It has a higher pH than other media. Remember to watch the pH carefully and be prepared to bring it to the range best suited for indoor growing with phosphoric or citric acid.
Best for: Aeroponic systems, in which the roots are exposed and only the top of the plant touches the medium, benefit from airy rockwool, which dries quickly, helping reduce the risk of diseases and fungi problems around the plants? stems and crowns.
Perlite
Perlite hydroponic growing mediumPerlite is mainly composed of minerals that are subjected to very high heat, which then expand it like popcorn so it becomes very light weight, porous and absorbent. Perlite has a neutral pH, excellent wicking action, and is very porous. Perlite can by used by itself, or mixed with other types of growing media?s. However because perlite is so light that it floats, depending on how you designed your hydroponic system, perlite by itself may not be the best choice of growing media for flood and drain systems.
Perlite is widely used in potting soils, and any nursery should carry bags of it. However perlite is sometimes also used as an additive added to cement. You may find it for a better price with the building supply?s, and/or at places that sell concrete mixes and mixing supply?s. When working with perlite be careful not to get any of the dust in your eyes. Rince it off to wash out the dust, and wet it down before working with it to keep the dust from going airborn.
Pros:
Perlite pulls moisture from reservoirs and gradually disperses it to plants? roots.
It?s naturally sterile, helping to protect your plants from diseases.
You can find perlite at any garden center, and even large amounts are very inexpensive at big-box home stores.
Cons:
Tiny little grains of perlite tend to wash away when the growing system is flushed, so you must continually replenish it or your plants? roots may be exposed to air.
Perlite dust can irritate your lungs, so it?s best to wear a mask when working with it.
Branded bags of perlite may have added fertilizer ? stick with pure perlite so you keep control of your plants? nutrient levels.
Best for: The tiny grains are especially useful when you?re working with small, fragile plants, such as when you?re starting clones.
CLAY PELLETS
What: Lightweight expanded clay aggregate is clay that?s been pelletized and fired in kilns until it expands into small, orangey-red balls. They?re often called grow rocks.
Pros:
The superabsorbent pellets quickly suck up and hold excess moisture.
Their round shape is sturdy and gentle on plants? roots.
They have a neutral pH and leach no minerals into the nutrient solution.
Grow rocks are reusable, if you take the time to clean them thoroughly between each growth cycle.
Cons:
As the pellets age, they break down and the clay can clog pumps and emitters.
You can order bags of the pellets online, but they?re not found in every local garden center. And they?re more costly than perlite or coir.
Best for: Use in top-drip growing, where the nutrient solution can trickle down through the pellets to the roots.
Pine shavings
Pine shavings are an inexpensive hydroponic growing media as well, and a lot of commercial growers use it. Generally for large scale hydroponic drip irrigation systems. Don?t confuse pine shavings with saw dust. Saw dust will become compact and water logged easily. You?ll want to make sure your pine shavings were made from kiln dried wood, and does ?NOT? contain any chemical fungicides. Kiln dried to burn off all the sap in the wood that is bad for the plants. Most pine shaving products would be kiln dried to begin with.
Good source to find pine shavings are pet supply stores. Its used for things like hamster and rabbit bedding. Just make sure to read the package to be sure it doesn?t have any chemical additives like fungicides or odor inhibitors. You should be fine if it states it?s organic. Another good cheep source for pine shavings is at feed stores, it?s also used as bedding in horse stalls and they sell it by cubic yard. If you have a choice get the largest partial size you can. The larger the air pockets between the shavings, the better aeration to your roots.
Pine shavings are a wood product, so they absorb water easily, thus can become water logged easily. So make sure you have good drainage so the shavings don?t sit in water. If there is a possibility of it sitting in water, a layer of rocks at the bottom will aid drainage greatly.
In conclusion
There isn?t one growing media that is better than the rest. Especially with so many different hydroponic system designs possible. However many growers eventually favor one type over others. There are a lot of things to consider when choosing what to use as a growing media. The type of system your growing in, and how you design and build that system is the biggest factor.
While there is no one best growing media for all situations, some growing media?s work better than others in different systems. With any hydroponic system, and/or any type of growing media, the goal is still the same. You just need the roots to be moist, not soggy and saturated. If the growing media is saturated and soggy, the roots will suffocate from lack of oxygen. That situation can easily lead to roots dying, and root rot.
If you use hydroponics to grow marijuana at home, then you need a good grow tent.Grow tents are definitely important to indoor aquaponics/hydroponics growers because they keep out smells from the rest of the house and also thermo-regulate the plants? surroundings, ensuring proper temperature and ideal growth parameters.
