6 Main Hydroponic Systems and How They Work

If you’re a hydroponic newbie, you’ve probably stared long and hard at the different systems, wondering which one will suit you best. The choice is overwhelming, and delving into the extensive theory could leave you more confused, with a headache to boot! We’ve compiled this quick and dirty guide to give you the basic lowdown on the 6 main hydroponic systems.

Different systems may work off alternate principles and use variable hardware, but the ultimate needs of the plants remain the same- an adequate supply of water, nutrients and oxygen. How these necessities are delivered is what sets hydroponic techniques apart from each other.

The system you opt for will depend on a number of factors. Time and money will have a bearing on your decision, but more importantly, the type of plant you wish to grow also needs to be considered. Size, nutrient needs and water consumption will have a huge influence on which growing methods are suitable for your hydroponic garden.

Wick Hydroponics

Wick Hydroponics

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Looking for an uncomplicated, easy to manage system? Then wicking is your hydroponic dream come true! With no moving parts (ie, a passive system), wick setups are electricity free, meaning you don’t have to worry about power outages ruining your crops.

How It Works:

Wicking systems consist of 4 basic pieces of equipment:

  • Grow tray
  • Reservoir
  • Growing medium
  • Wicking rope

An air pump is optional, as the plants will absorb oxygen from air pockets in the growing medium, but for better oxygenation of the water and to disperse the nutrients more evenly, aeration is your friend.

The principle of the system is basic but effective. Nutrients are added to the water, which are then absorbed through the wick and into the roots of the plant by capillary action.

Suitable mediums include vermiculite, perlite and coconut fibre.

Pros and Cons:

  • Inexpensive and uncomplicated
  • Doesn’t require electricity
  • Ideal for small plants and herbs
  • Nutrients aren’t absorbed as effectively as other hydroponic methods
  • Not ideal for larger plants that require lots of water and nutrients

Drip Systems

hydroponics drip system

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Drip systems are popular among commercial and domestic growers alike. Versatile and efficient, the concept of the drip system is straightforward and doesn’t require a complicated setup.

Drip hydroponics doesn’t require large volumes of water, which makes it the perfect system for growing larger plants with wide spreading roots. The method of delivery also offers lots of control over the supply of nutrients and water.

There are 2 types of drip systems- recovery and non-recovery. A recovery system collects any excess nutrients, recirculating them back through the circuit. This means that recovery systems are extremely efficient, and they deliver a balanced nutrient solution regularly without the need for a precise digital timer. Non-recovery systems do not reuse the excess nutrients, and as a result, they require a precise timer to ensure that the plants are sufficiently hydrated and fed.

How It Works:

To build a drip system, you need:

  • A grow tray
  • Water reservoir
  • Submersible pump (any pond or fountain pump will do)
  • Light timer for the pump
  • Growing medium
  • Tubing and connectors

The tubing and connectors form the plumbing system between the grow tray and reservoir, and are also used to create an overflow valve for run-off. Again, an air pump and stone would be beneficial to promote aeration of the water and nutrients, but is not strictly necessary. Drip emitters are another optional extra, however, they become easily clogged. The same effect can be achieved without the hassle by making tiny holes in your drip lines.

The timer switches the pump on, and the nutrient solution is pumped from the reservoir up into the drip lines. It is then dripped into the growing medium, where it drains down into the roots. In recovery systems, the excess then flows back into the reservoir through the overflow valve.

Pros and Cons:

  • Relatively straightforward and inexpensive
  • Uses nutrients efficiently
  • Disperses nutrients evenly
  • Excellent for larger plants
  • Lots of control over watering cycles
  • Recovery systems require more maintenance to keep the PH balance of the solution
  • Non-recovery systems require precise, reliable timers

Ebb and Flow/Flood and Drain Systems

Ebb and Flow Flood and Drain Systems

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Ebb and flow systems are ideal for growing small to medium sized plants. The design of the flooding tray makes it an excellent temporary home for plants that you plan on moving at a later stage. It’s a brilliant system for starting plants that will be relocated to a larger system as they grow.

Ebb and flow systems depend heavily on timers, so consider your growing medium carefully. Using a medium that preserves moisture will help your plants remain hydrated in the event of a power failure. Coconut, rockwool, vermiculite and soilless mixes are good moisture retaining mediums.

When using this method, you may prefer to put your plants in individual pots filled with growing medium. This will make them easier to move or transport down the line.

How It Works:

Ebb and flow systems use:

  • Grow tray (flooding table)
  • Reservoir
  • Submersible pump
  • Growing medium
  • Tubing

The timer is set to come on for a few minutes a number of times a day. When it switches on, the pump pushes the nutrient solution from the reservoir into the grow tray, flooding it to the level of the overflow tube. Once the timer shuts the pump back off, gravity drains any excess solution back through the original delivery tube and back into the reservoir.  Air pumps and stones are optional but will ensure that the nutrients remain evenly distributed in the solution.

Unfortunately, the design of the ebb and flow system makes it susceptible to algae growth, so the grow table will need to be cleaned regularly.

Pros and Cons:

  • Great for plants that need to be moved
  • Efficient use of nutrients
  • Inexpensive
  • Requires regular cleaning
  • Uses a large amount of growing medium
  • Dependant on electricity


nutrient film technique

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N.F.T (nutrient film technique) is mainly used for small fast-growing plants such as lettuce and herbs. N.F.T systems don’t require a growing medium. Instead, the plants sit in a basket with their roots dangling freely in the grow tray.

Since the nutrient flow is constant, timers aren’t necessary. Instead, N.F.T systems are heavily dependent on their pump. Combined with the lack of growing medium, this means that the plants are vulnerable, and in the event of a pump failure, the roots can begin to wilt in as little as a few hours.

How It Works:

N.F.T systems sound complex, but they are relatively painless to construct. You need:

  • Grow tray (also called a growing tube or gully)
  • Reservoir
  • Submersible pump
  • Baskets to start seedlings in
  • Tubing

The pump delivers the solution through the tubing into the grow tray, which is set at an incline. The solution flows down the grow tray and drains back into the reservoir through the return tubing where it is then recirculated continuously.

An air pump and stone are an optional extra that will keep your solution oxygenated and prevent the growth of algae.

The recommended slope for an N.F.T grow tray is usually 1:30, which means that for every 30 inches of tray, there should be one inch of drop. The optimal flow rate for the nutrient solution is typically a 1-2 litres per minute for each tray. Having the flow too high or low could result in nutrient deficiency.

Pros and Cons:

  • Brilliant for fast growing plants
  • Saves the expense of using a growing medium
  • Will die very quickly if the pump fails
  • Requires regular cleaning as roots can clog the system

Water Culture

Water culture hydroponics

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Water culture is the most primitive of all hydroponic systems. Simple and easy to manage, it is the perfect system for experimenting with, and can be constructed from materials found around the house. Unfortunately, leaf lettuce is about the only plant that thrives in a water culture system, so if you do opt for this setup, you might find yourself eating a lot of salad!

How It Works:

To build a water culture system, you need:

  • Reservoir
  • Air pump, stone and hose
  • Baskets or pots to hold the plants in place
  • Growing media (usually styrofoam)

The concept of water culture systems is amazingly basic. The reservoir acts as an all-in-one, so there’s no need for a separate grow tray. The plants are supported by baskets or pots which are set into a styrofoam platform. The platform floats on the nutrient solution, meaning the plant roots are submerged constantly. Because of this, the water needs to be constantly aerated to deliver enough oxygen to the roots, so ensuring your air pump is working correctly is crucial.

Pros and Cons:

  • Inexpensive and easy to setup
  • Easy to use on a large scale
  • Limited range of plants that can be grown
  • Not suitable for larger or longer growing plants
  • Dependant on air pump

Aeroponic System

Aeroponic System

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If you want your plants in a hurry, then this is the growing method for you! Aeroponics is the most high-tech of all the hydroponic methods. Similar to N.F.T, aeroponic systems use air as the primary growing medium. The roots get maximum oxygen, resulting in rapid plant growth and maturity.

Using air as a medium means the plants are very vulnerable to wilting if the watering cycle is interrupted.

Aeroponics uses less water than other hydroponic methods, meaning it is kinder to the environment, and less expensive for the gardener.

How It Works:

You can build your own aeroponics system with:

  • Reservoir
  • Timer
  • Submersible pump
  • Enclosed growing chamber to act as the root zone
  • Tubing
  • Mister heads

It might seem complicated, but the principle of aeroponics is simple enough. The plants sit in baskets that are set into holes at the top of the reservoir with their roots suspended in air below. Nutrient solution is pumped up into the tubing and through the mister heads at the top, spraying the roots with a fine cloud of solution. The timer is set to switch the pump on every few minutes, ensuring the roots remain hydrated and nourished. Because of this, a special short cycle timer is required.

Pros and Cons:

  • Plants grow rapidly
  • Less water is used
  • No need for growing medium
  • Mister heads clog easily
  • Heavily dependent on water pump for survival

Is Aquaponics a Type of Hydroponics?

Many people assume that aquaponics is also a type of hydroponics, but this isn’t strictly true. Hydroponics is a method of delivering water, nutrition and oxygen to plant roots without using soil. On the other hand, aquaponics is the process of using fish waste to provide adequate nutrition to plants. Aquaponics and hydroponics often go hand in hand, but are two very different things.


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