Hydroponics is more than merely submerging plant roots in a nutrient-rich liquid. Different types of hydroponic systems are used to developed and support different kinds of plants.

Overall, there are four classifications of hydroponics systems: Water Culture System, Aggregate System, Active System, and Passive System.

However, it is essential to consider that a hydroponic system consists of standard parts; thus before learning about the different types of systems, it is crucial to understand the necessary elements of a hydroponic system first. It is really vital to discuss these elements/parts before discussing the techniques.

Growing tray – The growing tray holds the root system of the plant and can be made from different types of materials.
Reservoir – It is a chamber that holds the nutrient solution used to feed to the plants.

Submersible pump – The pump is used to water the plants. Not all hydroponic systems require a submersible pump.
Delivery system – the delivery system can be anything that delivers the nutrients to the plants. It can be vinyl tubing or a wick depending on the requirements of the system. There several ways of designing the system itself.

Timer – The timer is a device that turns on and off the pump at regular intervals.
This particular device is essential to prevent the plant roots from drying out. However, not all types of the hydroponic system require a timer.

Air pump – An air pump has a different purpose with the submersible pump. The air pump provides oxygen to the nutrient solution. Although this particular system is not necessary, some serious hobbyists use this device to minimize the algae growth and to make sure that the nutrient solution stays fresher for a long time.

Lighting source – An optional element in your hydroponic system, a lighting source is only necessary if the system is located inside a building where access to natural sunlight is improbable.

With that being said, let’s move on and see what can be the basis for our growing methods, once correctly supported by all of these elements together.

Different Types of Growing Medium Used In Hydroponics

On the other hand, there are also different types of growing medium that are available for the different types of hydroponic systems, and it is also crucial to understand what they are first before discussing the different hydroponics techniques. The purpose of growing medium is to provide aeration and support to the plant’s root system. Moreover, they also serve as channels for the nutrients and water to reach the plant’s roots. It is crucial to consider that different types of hydroponics system require different types of growing medium. There are several types of growing medium available for your hydroponics system, and below is a list of the most common types of growing medium used in hydroponics.

Grow Rock

Also called hydro-corn, this particular growing medium is made from lightweight expanded clay aggregate that is formed into a shape of small rocks. This specific growing medium is very porous and provides full support to the plant’s root systems. This particular growing medium is reusable, thus making it a perfect option among novice hydroponics enthusiasts.

Rock Wool

This particular type of hydroponics system is sterile and porous. It is made from granite and limestone that has been melted down and spun just like wool. This growing medium is compressed and formed into sheets, blocks, and cubes. Rockwool absorbs moisture effectively. In fact, this particular growing medium can hold 20% more air, thus making it perfect for hydroponic systems that do not use air pumps. On the other hand, this particular growing medium has a pH range of 7 to 8, which can significantly affect the pH of the nutrient solution in the reservoir.


Perlite is made up of minerals that are processed under high heat to make them expand and to give them high absorbent properties. Perlite is lightweight and can even float on top of the water. It can hold a lot of moisture and also air. This particular growing medium is best used in the drip system and is often used with other types of growing medium. Because it is lightweight, it is not used to support large plants.

Coconut Fiber

An organic growing medium that is used in hydroponic systems, coconut fiber has a consistency of good potting soil. The best thing about this particular medium is that it does not become easily compacted, thereby allowing better aeration for the plant’s root systems. In fact, this specific growing medium holds more oxygen than others, and it can help maintain a neutral pH. However, unlike other growing mediums, coconut fibers are not reusable.


Similar to perlite, vermiculite is made from minerals that have been subjected to high heat. This particular growing medium has a high cation exchange capacity, thus allowing it to hold nutrients more effectively than other growing medium. This lightweight growing medium is a perfect option for the ebb and flow technique, and it works well with different types of growing medium such as perlite. It can be mixed 50/50 with perlite.

Now that we know which support we may have on our hydroponics system lets move on and classify each one of them

Classification of Hydroponics System

There are four general classifications for hydroponic systems. Those include the water culture system, aggregate system, active and passive system. These systems vary based on how the nutrients apply as part of the system.

Aiming to give a more precise understanding, below there is a detailed description of each classification of hydroponics system:

Water Culture System

This particular system provides a constant supply of the nutrient-rich solution to the plant’s roots. Examples of this hydroponics system include the film and aeroponics techniques. The types of systems under this classification use a pump or an aerator to make the nutrient solution bubble up for the plant roots to touch.

Aggregate System

This classification of hydroponics system uses growing medium like vermiculite, perlite, gravel, or rock wool to support the root system of the plant. The plant is then flooded and drained with the nutrient medium at regular intervals. An excellent example of the aggregated system is the Ebb and Flow method.

Active System

This particular system is straightforward because it leaves the roots submerged to the nutrient solution to absorb the minerals actively. An excellent example of the active hydroponics system is the deep water culture wherein the roots are exposed to the nutrient-rich solutions

Passive System

As the name implies, this particular system uses growing media or a wick to absorb the nutrients from the solution. A perfect example of this specific classification is the wick method which allows passive absorption of the nutrients from the nutrients to the plant.

These four classifications of hydroponic systems are further sub-divided into different methods, and the following sections will discuss the different hydroponic techniques as well as their advantages and disadvantages.


There are several types of medium to support our system, as well there are several “approaches” for us to move forward, based on the type of grow we want to achieve. Proper tools/elements are the all way critical for us to succeed on this.

Good Growth!