How The Ebb And Flow System Hydroponics System Works

How The Ebb and Flow Hydroponics System Works

After studying almost all types of hydroponics systems, we have come to the conclusion that ebb and flow (also known as flood and drain) is one of the most inexpensive options with a great amount of versatility. This is why it has become so popular among commercial growers and gardeners.

It allows you to scale up or scale down at any given time, without worrying about disturbing the hydroponics ecosystem. Just place the plants in the tray. Water them regularly with a pump, and the plants will grow happier and healthier.

More on how it happens later, let’s first understand what ebb and flow means?

Ebb, as used in the phrase “ebb and flow” refers to the cyclical movement of the tides from low to high and repeat. Ebb and Flow hydro farming functions on the same lines. The water ebbs and flows to the plants and then moves back again, giving it its name.

You may ask, “Does drain spell dryness?” The answer is no. When there is no water in the tray during the dry spell, the plants start growing out roots looking for more moisture and absorbing oxygen (another essential element for healthy growth). Thus helping the plant grow.

Isn’t this useful?

Now without much ado, let us shed light on the various elements that help water ebb and flow in a hydroponics system.

ebb and flow hydroponics

Ebb and Flow System Hydroponics System Components

Most of the components of an ebb and flow Hydroponics system are the same as other systems. 

  • Grow tray
  • Grow containers
  • Overflow tube
  • Growing medium
  • Nutrient solution reservoir
  • Submersible pump
  • Timer
  • Air pump

These work in synergy to bring out the best in your plants.

Grow Tray

In an ebb and flow hydroponics system, the grow tray is also known as the plant tray or the flood tray. Usually, it is a large shallow tank or several small ones to grow your plants. These are placed on a tall stand.

Grow Containers

You can either place your seedlings/plants directly into the grow tray or in perforated pots filled with grow medium. The plants receive essential nutrients and grow from here.

Overflow Tube

The overflow tube is the bridge between the grow tube and the reservoir moving water in and out of the grow tray/container. It maintains the height of the nutrient solution. Other than this, it ensures that no water spills out of the system. The latter may occur due to the pressure build-up in the system.

Grow Medium

The system makes it necessary to add a growing media into the ebb and flow hydroponics system. A few common growing media used in this technique include perlite, hydroton, stone wool, and clay gravel.

When picking a grow medium, check the following.

  • Retention ability: The best grow medium for an ebb and flow system is the one that drains well but also retains moisture well. Hydroton clay pebbles and lava rock are the ones with these features.
  • Buoyancy: Make sure your grow medium is strong enough to hold the water and grow medium.
  • Strength: When growing any plant with a solid root mass, it is vital to have a deep grow bed. For example, vegetable roots push the grow medium to form a mass and need some space to expand out.

The Reservoir

Right below the grow container is the reservoir. A fill tube and a drain tube connect the two containers. Fill tube connected to the submersible pump controls the water flow in and out of the tray. Post flooding the grow tray, the gravitational pull drains the water back to the reservoir.

Submersible Pump

At the base of the reservoir, there is a submersible pump. The fill hose is attached to it. The strategic position of the reservoir (underneath the flood tray) reduces the distance the water has to travel.

The submersible pump regulates the frequency and the time phase water is allowed to flood the water depending on the requirement of the plants.


A timer controls the amount of time the water is allowed to flood the grow tray. The duration depends on the nutrient requirements of the plants growing and thereby sufficiency.

Air Pump

While some growers prefer introducing air into the nutrient solution from above the tube when it returns to the reservoir, a more preferred option is an air pump.

ebb and flow

How Does The Ebb And Flow Hydroponics System Work?

As you turn on the pump, the nutrient solution moves from the reservoir to the grow tray. It continues to flow till the container attains a certain water level. The overflow tube sets the limit (as already told to you).

When the determined overflow height is attained, the pump is turned off, and the water moves back to the reservoir from where it is remixed with the nutrients and recirculated back to the grow containers.

Note: Ebb and flow hydroponics systems come in different designs. But the functioning remains the same.

Follow along and take a round up of various types of ebb and flow hydroponics systems.

Types Of Ebb And Flow Hydroponics Systems

There are four types of ebb and flow hydroponics systems.

Flooding Tray

In this, the system is made up of a single container. It could be a square-shaped tray or a rectangular tray placed above a raised surface. The reservoir is stationed right below the flooding tray. The nutrient solution moves from one end of the tank to nourish the plants. The opposite end drains the water back to the reservoir due to gravity.

You can grow plants in a plastic bucket with a befitting grow media as the overflow tube regulates the flow within a container.

Multiple Grow Container (Single Pump)

The multiple grow container design receives the nutrient solution through pipes underneath each connector with a T connector. The latter is responsible for moving the solution to the bottom of each tray.

All containers receive nutrient solutions simultaneously and rise to a level controlled by the overflow pipe. It is then drawn back to the reservoir placed beneath.

Surge Tank Design (with two pumps)

With more vertical space, this design supports bigger plants. In this type, the grow containers are not raised but kept on the floor. Since they are on the same level as the floor, you need a second pump to drain the water out.

The pump is placed in a smaller container, known as a surge tank, to control the solution level.

The Dutch Bucket

One of the most popular ebb and flow hydroponic systems is The Dutch Bucket. As the name suggests, it features a single bucket or multiple buckets, with each bucket having a single plant embedded in grow media. A larger bucket (reservoir) contains water and nutrients.

A submersible pump in the reservoir pushes the nutrients via a drip line to drop onto the growing plants via drip emitters. The bucket elbow below each bucket drains the liquid back to the reservoir.

Tips to receive the most from your Ebb and flow system

  • The pots should be 2x double than the grow tray
  • The growing medium must be strong and heavy so that it does not become soggy. 
  • When to refill water in the reservoir depends on the type of plants you intend to grow and the contaminants.

Wrapping Up

The ebb and flow system is a simple hydroponics system. Both oxygen and nutrients are provided to the plants at one go (flooding). The plant roots do not stay completely immersed in the solution. After the water drains, the roots are again exposed to take up more oxygen. Therefore there can never be oxygen depletion in the system.

Ebb and flow are easy to set up. You can decide the scale as per your requirements. However, it demands a little maintenance, but the flexibility makes it all worth it. So, if this hydroponics system sounds appropriate, go ahead and own one.