Hydroponics is the new trend in farming that is quickly catching on with all farmers. Many countries are adopting this method of farming to produce high yield and faster growing crops. Hydroponic is also advantages in the fact that we don’t have to check about the season for crop growing or do tedious work as soil rotation, ploughing etc.
Through hydroponics we can grow most of the crops free from soil and also in limited space which can be indoor or outdoor. Indoor hydroponics gives the benefit of providing artificial light so that we can create crops through snow or rain. By investing an amount in the beginning we can ripe the profits for a long time.
Hydroponics is the new technology to grow plants without soil ‘soilless farming’. In hydroponics the plants are grown in nutrient rich solutions kept in containers. There are many different systems in hydroponics starting with the basic that doesn’t require any equipment to the advanced that require a many systems to work together smoothly to give the result.
Among the six systems popular in hydroponics we are going to see the ebb and flow system here. As the name indicates it has to do with the flow of nutrient solution.
EBB AND FLOW – what is it?
As the name suggest ebb and flow indicate the nutrient flow similar to tides in sea. Ebb indicates the retreating water and flow indicates the incoming water. So in this hydroponic system the plants are supplied nutrients using the ebb and flow technique. It is the most cost efficient, very low investment and reliable form of hydroponics. This is also known as the flood and drain system.
In this system the grow tray is flooded with the nutrient solution using a pump and then the excess nutrient is returned to the reservoir by action of gravity via an overflow outlet. These two phases of flooding the tray and then emptying it take place on a regular basis thus the name ‘Ebb and flow’ or ‘flood and drain’.
How it works?
There are two containers – one is the growing tray and the other is the reservoir. There is a water pump and an overflow regulator. The timer automates the entire process. Once the timer goes on the water pump is turned on and the nutrient solution from the reservoir is pumped into the growing tray flooding the plant roots in nutrient solution till the top of overflow outlet.
The overflow outlet prevents the plants from being fully submerged in the nutrient solution. When the timer stops the water pump stops the pumping of water and the excess water is drained through the overflow regulator back to the reservoir by action of gravity.
As you can see the system is simplified than the other systems in hydroponics. The aerated and nutrient rich water is provided to the plant in one single flooding action and the roots are not staying fully submerged in the solution thus preventing the oxygen depletion issue. Once the water drains off the roots are again exposed to air that they can take up much more oxygen than in any other system.
Oxygenation in ebb and flow system is very simple and passive. There is no need of equipment for oxygenation. Once the plant roots are flooded with nutrients and then drained off due to gravity they are exposed to the space and air around them. So the roots are free to absorb the oxygen from the air around them instead of being submerged in water. The exposure to high oxygen content around the roots also prevent them being affected by pathogens, thus eliminating the issue of root rots and other kind of diseases.
Building one on your own
The flood and drain system is very simple and easy to assemble. There are no high end equipments used, you can basically create one with the simple things around your home.
The materials required are as follows.
A grow tray – any tray or container with a height to incorporate the plant and the roots.
Reservoir – any container or bucket that can hold the nutrient solution.
A water pump – it can be a submersible pump or and outside pump.
Timer – this is optional, this automate the flooding process.
Tubes – tubes are required to take the water up to the tray and then drain it out.
Overflow tube – this is the single most important requirement as it maintain the water level in the grow tray and also drain the water back to the reservoir.
Growing medium – growing medium is used to just anchor the plants in the pots. Many growing medium are available that can be used like hydroton, vermiculite, perlite, rock wool, coco coir etc.
Net pots – net pots of the size you desire.
Factors to consider on selecting growing medium
When selecting the growing medium a few points should be kept in mind.
In this system the tray gets flooded and then it’s drained so there should be some moisture retained in the growing medium for the plant roots. So a moisture retaining growing medium can help in this situation like leca or lava rocks.
It is advisable to used a higher weight material as we don’t want the plants to tip over when the grow tray is being flooded with water as light weight medium can cause it to float.
When growing root vegetable – in this case the root vegetable will grow in the net pots and this causes the growing medium to be pushed aside so the best material to be used in this case would be clay pellets or lava rocks.
Plants for flood and drain system
It is a known fact that many plants can be grown in hydroponic system but not all of them can strive in this environment so it is best to select a few plants that can actually flourish in the conditions provided.
Best plants that can survive in flood and drain
Tomatoes– any hybrid tomatoes will flourish in this system
Radish – it’s a root vegetable so we need to take care to provide the apt growing media and pot for it to develop.
Kale – it is a very nutritious and healthy plant that thrives hydroponically.
Cucumber – they grow very well in hydroponic conditions. The good quality about cucumber is that it grows fast and produce high yield.
Lettuce – lettuce is a plant that can thrive in any hydroponic system
These are few of the plants to name there are many more so do the research and grow the plant that is apt for your hydroponic system. For some plant you may need to provide grow light to control the light requirement if you are growing them indoors.
Types of flood and drain system
There are many variations to the ebb and flow system. They all use the same method to provide the plants with the nutrient hey require. The difference would be in the set up of the materials.
Flooding tray design
The flooding tray set up is usually used for the starting of seedling plants. Later the seedlings can be moved to more permanent hydroponic system. This uses a rectangular tray of certain depth and kept at a height the reservoir is usually kept below for easy draining purpose. The growing media used is usually clay pellets and net pots are used to hold the plant and the medium. The top of the tray is not covered up so the one drawback of this method is that the nutrient solutions are exposed to light so there is a chance of algae formation. This requires the tray to be cleaned in regularly to prevent diseases.
Containers in series
As the name suggests in this design the plant containers are connected to each other via pipes and then connected to a common overflow tube and a reservoir. This method helps to flood many containers at the same time so large scale production of the plant is possible. The water level that is to be maintained in all the containers is controlled by the overflow tube by adjusting the overflow tube we can maintain the water level in each of the containers and once it’s attained the excess water will drain off to the reservoir place below.
Surge tank design
This is different from the traditional flood and drain design. This doesn’t use a overflow tube to maintain the water level in the grow containers instead it uses two pumps to control the water inflow and out flow. One pump takes the water from the reservoir into the plant container and the other pump pushes the water from the containers back into the reservoir.
In this set up the first pump fills the plant containers with water evenly by pumping it from the reservoir on the water level reaches a certain height then the floating valve turns on the pump which pushes the water from plant containers back to a surge tank from where it goes to the reservoir.
This method requires extra equipments and is totally depended on the pumps for inflow and drainage.
This is similar to containers in series or surge tank system the difference being that the plants are grown in buckets. This is also called as Bato bucket system. This works the same way as surge system where the nutrient solution is pumped into each of the bucket and then drained using a pump or here we can also drain the nutrient solution out individually from each bucket without the use of pump.
We can also connect drip emitters to supply the nutrients to the individual buckets. This gives us the freedom to plant different types of crops.
As with all the hydroponic systems there are some pros and cons with this system also. Let’s see what are the advantages and disadvantages of ebb and flow method.
It is low cost – the materials used for the creation of ebb and flow system doesn’t require huge amount. Some of the basic material around your home can be converted to create a ebb and flow system.
Ease of use – its working is not rocket science. The basic working principle is very easy to understand. If any issues are faces you yourself can analyze the problem and provide a fix.
Nutrient supply – in this system the nutrient supplied to the plants are high enough for all the plants equally. The pumping of water from reservoir to tray drenches all the plants equally with nutrients thus ensuring full development of all the plants.
DIY – you can make the ebb and flow system as per your needs by learning the basic principle and the working. There are numerous tutorials available that help you achieve the task with perfection.
Cleaning routine – the cleaning routine can be tiresome as we need to wash and sterilize the growing tray frequently. There can be pathogen build up in the tray to the stagnant water in the flood and drain system. So it is important to take apart the growing tray and clean it thoroughly with a solution of hydrogen peroxide.
Tangled roots – in the grow tray the roots of the plants can get tangled together during their growing period this makes it difficult when we have to remove a plant that is affected by disease without disturbing the other plants.
pH variation – as the flood and drain system is a recirculating system, after a period there can be variations in the pH level of water in the reservoir. This can lead to poor plant growth and low yield. So it is very essential to ensure that the pH level is maintained at an optimum.
Hydroponics as mentioned earlier is the farming of the future with the current limitations in space this method offers a great way to grow your plants without the hassle of dirt.
Among the hydroponic systems flood and drain or ebb and flow method is the most versatile, reliable and easy. We can make it by ourselves according to our requirements, with the materials from around your home. They don’t demand any high end equipments and it’s easy to maintain also.
As with all the systems there are both advantages and disadvantages that we need to take into consideration. But if you are ready to start your hydroponic garden then I would suggest flood and drain system to the apt one.