Of all the various types of hydroponics systems out there, one of the best you can choose is ebb and flow hydroponics.

Also known as flood and drain hydroponics, this system produces incredibly clean, heavy plants in an efficient, automated matter. As a result, commercial cultivars and hobby growers around the world are asking questions like:

  • What is ebb and flow hydroponics?
  • How does ebb and flow hydroponics work?
  • What are the ebb and flow pros and cons?
  • How do you build a flood and drain hydroponics system?

If any of these questions have been on your mind, you’ve come to the right place.

Today, we’ll address all these and many others you may have. By the end of this article, you’ll be well-versed in the world of flood and drain hydroponics. We’ve got a lot to cover, and we know you’re eager to discover what makes these types of hydroponic setups tick. So, let’s not waste any more time!

What is Ebb and Flow Hydroponics?

First things first – what is ebb and flow hydroponics? As you already know, this is a type of soilless growing system. And, it’s one of the most popular – right up there with deep water culture hydroponics. This system style has a rich history in the overall trajectory of the hydroponic growing timeline. It was one of the first types of systems to be designed specifically for soilless cultivation. And the name comes from how it works – flooding and draining the root zone on a set basis. To further understand how a flood and drain hydroponics system works, keep reading…

How Does Ebb and Flow Hydroponics Work?

ebb hydroponic system.jpg
Hydroponics Colored Infographic method of growing plants on artificial environments without soil and explain how vector illustration

So, how does ebb and flow hydroponics work?

While piecing all the components together and getting them to work together in harmony is a challenge, the actual operation behind these systems is quite simple.

First, you fill a reservoir with nutrient solution. Then, that solution is pumped into the grow tray – typically sitting on a stand above the reservoir – at regularly scheduled intervals.

This requires the use of a hydroponic water pump in coordination with a timer. This dictates how often the nutrient solution is pumped into the grow tray – and for how long the water pump sends the solution into the tray. When the timer goes off, the flood valve opens and allows water to flow into the growing area.

The flood valve stays open for a pre-determined amount of time – typically between 15 and 30 minutes. During this time, your plants’ roots are completely submerged in water & nutrient solution.

Once the flood valve closes, the drain valve opens and allows all the excess water to drain away again. This process repeats itself on a regular basis – typically several times per day.

It’s really that simple! But as you can probably imagine, there’s a lot more to learn about flood and drain hydroponic systems. How exactly do you piece all of the necessary components together? How do you maintain the system to keep it clean and optimized? We’ll talk all about this later on. First, let’s take a look at some of the advantages and disadvantages of these types of setups. 

Pros and Cons of Ebb and Flow Hydroponics Systems

Before you decide whether or not ebb and flow hydroponics are right for you, it’s important to understand all the pros and cons of ebb and flow systems. Let’s start with some of the reasons commercial cultivars and home growers alike love this type of soulless cultivation:


  • User-friendly Setup & Maintenance: These systems are easy to set up, easy to maintain, and easy to troubleshoot if something goes wrong. There are only two components that you really have to worry about: the water pump and the timer. If these stay dialed in, the system will work without fail.
  • Versatile Operation: You can use these systems to grow a wide variety of plants – from leafy greens and herbs to larger fruits and vegetables. Of course, this particular type of system lends itself perfectly to cannabis cultivation. You’ll find it in commercial facilities around the globe because you can fit tons of plants in each tray and make the most out of valuable space. You can space plants out and grow huge trees or cram as many plants as possible through sea of green hydroponics.
  • Water & Nutrient Efficiency: Because the roots are only submerged for a short period of time, there’s very little water or nutrient solution wasted through evaporation or absorption. And by draining the solution back into the reservoir and using it over and over again, you get the most out of your resources. You’ll still have to change out the water and solution altogether on a routine basis. But compared to other types of growing, this is one of the most resource efficient.


Really, the only drawback to ebb and flow systems is the upfront cost. They can be expensive – even if you’re looking into how to build a flood and drain hydroponic system DIY. That’s because you need more moving parts (the pump and timer, for example) than a more passive DWC system.

And due to how flood and drain hydroponics works, you need to invest in quality components. If you try and go cheap, you’ll end up with poor, unstable performance. Moreover, certain components will degrade over time faster as they’re constantly submerged in water.

The Verdict: Is This Cultivation Style Right for You?

Now that we’ve looked at some of the pros and cons of flood and drain systems, it’s time to answer the question: is flood and drain hydroponics right for you?

To answer that question, you’ll need to weigh the pros and cons of ebb and flow hydroponics for yourself. However, we recommend these primarily for intermediate growers, as they are a bit trickier to set up and maintain than other styles. 

With that said, we want to answer another common question we get asked: is ebb and flow better than DWC? It depends. 

One is not necessarily “better” than the other. Both can be used to grow remarkable plants that you’re proud to show off. Both are more efficient with resources than traditional soil-grown plants. However, one of these is the best beginner hydroponics systemand that’s DWC. If you’re more advanced and have experience with soilless growing, ebb and flow is a great next step up, though.

How to Build a Flood and Drain Hydroponic System: DIY Ebb and Flow Setup

Ready to learn how to build a flood and drain hydroponic system? These systems aren’t overly complicated – but they’re more difficult to construct than a passive setup like DWC. With that said, our guide on how to make ebb and flow hydroponics systems will have you feeling more confident getting your setup running. Let’s start by discussing step one in how to build a flood and drain hydroponic system: gather the components you need:

Grab Your Components & Growing Supplies

  • Grow Tray & Stand: This is what will hold your net pots and plants. It should be large enough to accommodate all the plants you want to grow, plus a little bit of extra space. As for the stand, it can be anything that elevated the tray a few feet off the ground – a table, stool, or special stand designed for flood and drain setups.
  • Hydroponic Reservoir: This is where you’ll store your water and nutrients. It should be made out of food-grade materials like plastic or stainless steel, have a lid to prevent evaporation, and be big enough to accommodate all the water your system will need. We recommend dark reservoirs, as lighter-colored reservoirs tend to let in light that can contribute to mold and mildew growth. They also are more difficult to keep dialed in without the use of a hydroponic water chiller.
  • Submersible Water Pump: This is how you’ll move water from the reservoir to the grow tray. It should be strong enough to flood the entire tray within a few minutes – but not so powerful that it erodes or blows out your tubing.
  • Timer: This is an important component as it tells the pump when to turn on and off. Look for one that’s easy to set and has a backup battery in case of power outages.
  • Overflow Drain with PVC Tubing: This drains any excess water from the grow tray back into the reservoir. Make sure the tubing can handle high temperatures in case your pump overheats – this is a common issue with flood and drain systems.
  • Net Pots: These hold your plants in place. They should be made of a durable material like plastic or ceramic, and have drainage holes so that water can flow through them easily.
  • Growing Medium: This is what your plants will grow in. The most popular options are perlite, coco coir, and rockwool. All three are great at holding onto moisture while still allowing roots to breathe.
  • Nutrients: You’ll need to fertilize your plants just like you would in soil – but different growing mediums require different nutrient mixes. Be sure to do your research so that you’re giving your plants the nutrients they need to thrive. If you’re looking for a specific recommendation, we have an article all about the best hydroponic fertilizer.

Piecing Your Components Together to Build a System

Step two in how to build a flood and drain hydroponic system is where the fun part starts: bringing it to life. Now that you have all the necessary components, it’s time to start piecing your ebb and flow system together. Here’s a step-by-step guide:

  • Step One: Place your grow tray on top of the stand or table you’re using. If you’re using a flood and drain stand, make sure it’s properly assembled before proceeding.
  • Step Two: Place your submersible water pump in the reservoir. We recommend putting it in a mesh bag first to keep it from getting clogged with debris.
  • Step Three: Connect one end of your overflow drain tubing to the overflow fitting on the grow tray, and route it back down into the reservoir. This will ensure that any excess water is drained back into the reservoir and not onto the floor.
  • Step Four: Fill your grow tray with enough of your chosen growing medium to reach the bottom of your net pots. Be sure to moisten the growing medium before adding your plants.
  • Step Five: Place your plants in their net pots, and add more growing medium around the roots until it’s level with the top of the pot. Gently press down on the medium to secure the plant in place.
  • Step Six: Once all your plants are in place, fill the reservoir with water and nutrients. We recommend starting with half-strength nutrients and gradually working up to full strength as your plants adjust to their new environment.
  • Step Seven: Set your timer, and plug in your submersible water pump. You should see water start flowing into the grow tray within a few minutes.

And that’s it! To help ensure you make it to harvest day with a happy, healthy crop, we want to provide some ebb and flow hydroponics tips & tricks for growing down below.

Ebb and Flow Hydroponics Tips & Tricks for Growing

As we mentioned earlier, growing in and maintaining a flood and drain hydroponics system is simple. Nevertheless, here are some ebb and flow hydroponics tips for along your first grow cycle.

Finding Your Ideal Flooding Frequency & Schedule 

The ideal flood and drain hydroponics watering schedule will vary depending on the type of plants you’re growing, the size of your grow tray, and the weather conditions in your area. You want to find a perfect balance because too often and you run the risk of drowning your roots and developing hydroponic root rot. In general, most plants will do well with 15-20 minutes of flood time followed by a drainage period of 30-60 minutes.

If you notice that your plants are wilting or showing signs of stress, it’s a good idea to look intro increasing/decreasing the frequency of your flood cycles. 

Monitoring & Adjusting pH, Temperature, & Nutrient Levels

You need to keep up on the pH, temperature, and nutrient levels of your system’s reservoir. We encourage you to run a daily check of these conditions. Plants are fickle beings – and if the pH isn’t dialed in, they’ll be unable to uptake certain nutrients – leading to deficiency.

The same is true of temperature – if the reservoir becomes too warm, plants will stop uptaking certain nutrients. This also invites the opportunity for algae or mold to take hold in the reservoir. And, you need to ensure the PPM of your nutrient reservoir is optimized. Your flood cycles aren’t just about keeping your plants’ roots moist – this is their feeding time. As PPM drops, you can top off the reservoir to keep your plants well-fed.

Much of this can be automated through the use of nutrient & pH dosers. We highly encourage you to invest in these if you’re a commercial grower. The elimination of human error and the cost savings of monitoring your crop at scale are well worth it. And even if you’re a hobbyist who wants to enjoy peace of mind and freedom from having to constantly monitor your plants manually, these are a great choice.

Cleaning Your System & Changing Out the Reservoir

It’s important to keep your flood and drain hydroponics system clean, both for the health of your plants and to prevent issues like clogged pumps and overflowing grow trays. We recommend cleaning out your reservoir and changing the water every two weeks, or as needed. You can also give your grow tray a quick rinse with fresh water every week to remove any build-up of nutrients on the sides or bottom.

As for how to clean your flood and drain system, it’s really just a matter of giving everything a good rinse with fresh water. If you notice any buildup in your pump or tubing, you can use a small brush (toothbrushes work well) to scrub it away. You can also fill your reservoir with a bit of fresh water and hydrogen peroxide to flush the system of impurities, bacteria, algae, and other harmful stuff you don’t want to infiltrate your grow.

Final Thoughts on Flood and Drain Hydroponics Systems

We hope this guide has given you a good understanding of flood and drain hydroponics systems – how they work, their advantages and disadvantages, and some tips for keeping your plants healthy and thriving. These systems are a great option for both commercial growers and hobbyists alike, thanks to their simplicity, flexibility, and low maintenance requirements.

If you’re thinking about setting up a flood and drain system in your home or greenhouse, we hope the DIY setup guide we shared earlier helps you hit the ground running. Happy growing!