An ebb and flow system, also known as a flood and drain system, is popular among home and commercial growers due to its ease-of-use, scalability, and efficacy. If you want to get started growing weed with a hydroponic ebb and flow system, we have got you covered.
What Are Hydroponic Soilless Systems?
Hydroponic systems do not use soil as a grow medium. Instead, the plant’s roots are supported by an inert medium such as hydroton clay pellets, Rockwool, and coco coir. The soilless root structures are suspended over a nutrient solution.
In a hydroponics system, the hydroponic-friendly fertilizers are mixed with the water. The nutrients and water mixture is pumped from a reservoir through distribution lines in a variety of methods.
Compared to soil-based plant roots, hydroponically grown plant roots have a smaller tap root. Instead, their roots are finer, almost hair-like, which helps increase their surface area and nutrient absorption. The ebb and flow system is one of the most popular, portable, and simplest hydroponic systems.
What Is an Ebb and Flow Hydroponic System?
An ebb and flow system is, by far, the easiest hydroponic system to set up at home. Through the grow medium’s capillary action, the roots can absorb the nutrient solution for a certain period of time. Then, the nutrient solution is drained in an “ebbing” process several times a day.
In an ebb and flow system, the pots are filled with Rockwool, coco coir, sand, or pea gravel instead of soil. These grow mediums can support the roots and provide a temporary home for the nutrient solution. Some growers use hydroton clay pellets due to their heavier form, which can support the plant better than coco coir or perlite.
The growing tray is flooded with the nutrient solution up to a certain point determined by the overflow tube. Then, the solution drains back to the reservoir through gravity. A submerged pump with a timer is scheduled for regular feedings several times a day. This ensures your plants get the appropriate amount of nutrients and water.
An overflow tube in the growing container helps keep the water level the same throughout and sends the nutrient solution back into the reservoir when the levels get too high.
Ebb and flow systems are the most common hydroponic methods of production and not just to grow cannabis either. Growers can grow a variety of edible and ornamental plants, including strawberries, lettuce, tomatoes, beans, peppers, and many more. In fact, the systems can be used commercially to grow acres of plants during a single growing season.
Ebb and Flow Pros and Cons
The advantages of an ebb and flow system include:
- Constantly moist roots
- Highly oxygenated environment
- Affordable
- Reliable
- Easy to set up
- Space saving
- Low maintenance
The disadvantages of an ebb and flow system include:
- Requires electricity to power the timers and pump
- Must regularly recycle nutrients and ensure the pH level is optimal
- Algae and other pathogens can begin to grow on the tops of the growing containers if not carefully monitored
- It can take some experimentation to get the timings just the flood and drain process. You must account for changes throughout the plant’s life cycle, strain type, grow medium, and many more variables.
- The plant’s roots can become tangled in the growing tray, which can increase their vulnerability of spreading a disease.
- Improper draining can increase the risk of root rot and plant diseases
Setting up your ebb and flow system is super easy. All you need are trays, a reservoir, and a water and air pump. Ebb and flow kits are available if you do not want to find the supplies from different sources. High-quality kits can start as low as $500.
Ebb and Flow System Types
Ebb and flow systems come in a variety of types. Generally, they all follow the same flooding and draining process. A nutrient solution is stored in a reservoir and pumped into the growing tray, container, or bucket, and drained back into the reservoir several times per day.
Ebb and flow hydroponics use nutrient solutions to keep the plants consistently absorbing nutrients and taking in oxygen. Each ebb and flow system varies in the method of filling the plant tray, ranging from top-down drip or a bottom-up fill.
Flooding Tray
A flooding tray system is one of these simplest and most common setups. All your cannabis plants can fit in a single container. If you are just getting started, this is a great starting point.
In this system, your growing tray will sit level on a raised surface with the reservoir placed underneath the tray. One hose is meant to flood the tray while another is meant to drain back the nutrient solution.
In the flood tray system, each plant will need its own pot or bucket with your desired grow medium. The system also uses an overflow tube to keep an even nutrient level.
Roots can get tangled if not carefully monitored. This system allows you to easily move plants without disturbing others, if necessary.
Containers in Series
The containers in series system allows growers to grow a variety of plant sizes and types using multiple containers. The containers are connected in a series with one tube that fills and drains the containers.
The draining process occurs at the same time throughout all the containers. The containers must be set up high with the reservoir below so that it can easily drain through gravity.
Overflow Tube
An overflow tube system is essential to maintaining a proper height of the nutrient solution in the plant tray. On a level tray, the nutrient solution can get to every plant container so that their roots can absorb nutrients. When setting up an overflow tube, its height depends on your desired water level.
Surge Tank
A surge tank system, also known as a dual pump hydroponic system, is an alternative to the overflow tube method and can add versatility and optimize space size for growers. In this system, a surge tank with a pump acts as an intermediary step between the reservoir and the growing containers.
The surge tank sits at the same height as containers unlike other systems that have the reservoir sitting below and use gravity to drain. This system uses several containers connected through a hose.
A submersible pump in the surge tank pushes the nutrient solution into the reservoir. A float valve inside activates the pump when the nutrient level is reached. When the surge tank is full, all the containers have nutrient solutions at the same level.
Dutch Bucket
The Dutch bucket system, also known as the Bato Bucket system, can be as small as one bucket or scale as your garden grows. While it works similarly to the ebb and flow system, this method uses buckets instead of trays.
Each bucket can contain one plant and drain back into the reservoir at a timed schedule. The reservoir pump sends the nutrient solution to drip all over the buckets as it drains through the media and out of the bucket. Dutch bucket systems are ideal for growing larger plants.
Ebb and Flow System Supplies and Equipment
Ready to get your ebb and flow system set up? Here is exactly what you will need.
Reservoir
A reservoir stores your nutrient solution. Its size depends on the size of your garden. We recommend an opaque colored reservoir to avoid algae and bacteria formation.
Submersible Pump
A submersible pump designed for a pond or fountain is an essential component that literally pumps the water from below into the growing tray. A pump with a strong flow rate is necessary to provide the plants with a steady and fast flow.
Timer
A timer helps you maintain a schedule for feeding your plants. Set the timer to ensure the pump sends the nutrient solution to the growing tray.
Container
A growing container is where the plants will grow. Plants can be placed on a broad and shallow container or you can use several smaller containers in an ebb and flow system. A growing container has two holes on the bottom to pump water in and drain it.
Tubing
Distribution lines in the form of pipes connect the different components to each other. The pipes can connect the nutrient reservoir to the growing tray and back in a consistent ebb and flow pattern.
We recommend feeding and draining with different tubing diameters. For instance, if you are feeding the growing tray with a ¾ inch hose, a 1 inch drain hose can work. This ensures the flow going back is faster than the flow going in to avoid completely flooding the table.
Overflow Tube
An overflow tube helps maintain a level height of nutrient solution inside the grow tray, buckets, or containers without risking soaking the plants. In addition, the tube can keep the nutrient solution contained without overflowing the grow tray.
Grow Media
Ebb and flow systems can work with various types of inert grow mediums. We recommend Rockwool due to its porosity and absorbent qualities. Other commonly used grow media include gravel, perlite, stone wool, and hydroton clay pebbles.
When considering different grow medium types, look for material that can hold onto moisture well and also drain properly.
Rockwool can be flooded between one and five times per day every 3 hours. If Rockwool’s not available, coconut coir or clay pebbles are worthwhile alternatives.
Coconut coir can be flooded between three to five times per day every 3 to 5 hours. Clay pebbles can be flooded between four times and eight times per day every two to four hours.
Nutrient Solution
Hydroponically grown cannabis needs a nutrient solution that gives the plant its vital components to grow big and strong. The best hydroponic nutrients will contain the plants necessary macro and micronutrients such as nitrogen, potassium, phosphorus, and calcium mixed in with the water.
The pH level for the hydroponic nutrient solution should be between 5.8 and 6.3. Depending on the grow setup, the nutrient solution can be replaced about every 5 days. Nutrient solutions with pH levels that are outside the optimal range can prevent proper absorption of nutrients.
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