Ebb and Flow hydroponics system, also known as Flood and Drain method, is one of the most well known methods of hydroponics and in recent years, has become the most popular method among new hydroponics enthusiasts. This method uses a reservoir to hold your nutrient solution. Above the reservoir will be a tray or growing chamber that will hold nutrient solution during flooding. There will be a pump in the reservoir that will take the solution up to the tray or growing chamber. Here the solution will sit, until the media can absorb the appropriate amount of solution, then it will drain. Some companies make ready to go Ebb & Flow systems, like the Flo-n-Gro Ebb & Flow System. You can also choose to buy the pieces separately, to design a system of your choice.


Advantages of Ebb & Flow

  1. You can reuse your nutrient solution.
  2. Requires very few parts to make up the system.
  3. You can use a small pump to run the system.
  4. This method doesn’t usually require a chiller.
  5. It is easy to build.
  6. It is easy to maintain.
  7. The cost of building an Ebb and Flow System is low.
  8. This method works well with organics.
  9. Any type of grow media may be used.

Disadvantages of Ebb & Flow

  1. You may run into a height restriction with the plants because of the height of the reservoir and tray.
  2. Salts and minerals can easily build up in the growing media due to bottom flooding in lieu of top flushing.
  3. Mineral build up can cause a nutrient lockout, which can also cause a nutrient deficiency.
  4. If you start with small plants, the flood height may not be able to reach the short roots in the grow media. You may need to top water or incorporate drip lines until the roots grow longer.

The Ebb and Flow system works by temporarily flooding the grow tray with nutrient solution and then draining the solution back into the reservoir. This action is normally done with a submerged pump that is connected to a timer.

When the timer turns the pump on nutrient solution is pumped into the grow tray. When the timer shuts the pump off the nutrient solution flows back into the reservoir. The Timer is set to come on several times a day, depending on the size and type of plants, temperature and humidity and the type of growing medium used.

The Ebb & Flow is a versatile system that can be used with a variety of growing mediums. The entire grow tray can be filled with Grow Rocks, gravel or granular Rockwool. Many people like to use individual pots filled with growing medium, this makes it easier to move plants around or even move them in or out of the system. The main disadvantage of this type of system is that with some types of growing medium (Gravel, Growrocks, Perlite), there is a vulnerability to power outages as well as pump and timer failures. The roots can dry out quickly when the watering cycles are interrupted. This problem can be relieved somewhat by using growing media that retains more water (Rockwool, Vermiculite, coconut fiber or a good soiless mix like Pro-mix or Faffard’s).


This type of system functions by flooding the growing area with the nutrient solution at specific intervals. The nutrient solution then slowly drains back into the reservoir. The pump is hooked to a timer, so the process repeats itself at specific intervals so that your plants get the desired amount of nutrients.

An ebb & flow hydroponics system is ideal for plants that are accustomed to periods of dryness. Certain plants flourish when they go through a slight dry period because it causes the root system to grow larger in search of moisture. As the root system grows larger the plant grows faster because it can absorb more nutrients.