How To Build A Recirculating Hydroponic System (Easy Tips)

A hydroponic system can help you grow your own vegetables and herbs at home in a very small space. 

These systems use nutrient-rich water instead of soil, allowing you to get more plants in a smaller space than traditional gardening methods would allow. 

The plants are also healthier because they have access to oxygen-rich water all the time (as opposed to being buried under soil).

How To Build A Cheap Recirculating Container For Hydroponics
Simple Tips for Building a Recirculating Hydroponic System
Plan your system before you start building
Choose the right container for your plants
Use high-quality growing medium
Keep your system clean and well-maintained
Monitor pH and nutrient levels regularly

Gather All Your Supplies

The supplies you need to build your recirculating hydroponic system are:

1 or 2 grow beds

A sump/reservoir for holding the water as it passes through the system (this can be any container that is large enough to hold all of the water from your grow bed(s). 

The reservoir should have an overflow drain so that if there are any problems with overfilling, it won’t damage the flooring below.

A pump capable of moving at least 1 gallon per minute (gpm) per square foot of grow bed space. 

If you’re using PVC pipe for your roots, this should be a submersible pump; otherwise, use a manifold pump mounted just above where you plan to locate your root zone. 

The best way to determine how much flow rate you need is by trial and error start small until you find out how well-drained your plants can tolerate before they start showing signs of stress or disease issues caused by too much oxygen exposure in their root zone.

When adding nutrients to your hydroponic system, it’s important to consider the type and amount of nutrients your plants need. Our guide on adding nutrients to hydroponics system offers valuable advice on how to provide your plants with what they need to thrive.

Setting Up Your Filtration System

The next step is to set up the filtration system. This is essential to keep your plants healthy, as it will remove all particles from the water and help prevent clogging of the emitters. 

The best way to do this is with a filter rated for your tank size.

The filter should be changed or cleaned periodically depending on how often you are using your system; if you have a large tank (such as 10 gallons or more), then changing out the filter every few months is recommended.

Setting Up The Fish Tank

Once you’ve decided on a tank, it’s time to set it up. The first thing you’ll need to do is make sure that the tank is large enough for your plant and fish. 

You can find out how many gallons of water your setup will need by looking at the recommended size for each plant in its guide book, or by taking a look at our chart below:

  • Tomato plants: 5-7 gallons
  • Blueberries: 2-5 gallons
  • Raspberries: 3-5 gallons

As far as what kind of material should be used for the bottom of your aquarium, there are two options available: an all-inclusive kit that comes with everything from fluorescent lights to fertilizer and pumps; or, if you’re feeling adventurous (or just want more room!), building one yourself using things like cinder blocks and Styrofoam sheets. 

Either way works well—the key here is making sure that there are enough holes drilled into the bottom so that excess water can drain out efficiently without clogging anything up inside.

Maintaining the correct pH in your hydroponic system is essential for healthy plant growth. If you’re struggling to raise the pH, check out our tips on bringing pH up in hydroponics to learn more about the causes of low pH and how to fix the problem.

Setting Up The Grow Bed

This is where your plants will grow, so make sure you’re using a container that’s large enough to provide enough space for them. 

You want it to be at least 30 gallons (about 120 liters) in volume and made of something that won’t react with the water or nutrients. 

Glass or plastic are both good options. If you’re using a plastic tub, don’t use one made from white polyethylene it’s toxic! 

Make sure there are holes in the bottom for drainage, as well as holes around the sides for air circulation and circulation of water when you’re topping off your reservoir tank with recirculation systems.

Set Up The Drain And Fill System

The fish tank needs to be connected to the grow bed. You can do this by putting the hose in place and making sure it doesn’t leak. 

If you have a big fish tank, you may need to add another hose so that there is enough room for the water in both tanks.

The pump will need to be hooked up too – this is what moves the water from one tank into another. 

You’ll also need some kind of timer device, which will let you control when your pump runs or stops running during certain times of day or night (this will depend on your climate).

On the other hand, if your pH is too high, your plants may not be able to absorb the nutrients they need to grow. Fortunately, our guide on bringing pH down in hydroponics can help you correct high pH levels and keep your plants healthy.

Set Up The Plumbing And Fill It With Water

Now that you’ve got all your supplies, it’s time to set up the plumbing.

Use a water pump and tubing to get the water from the fish tank to the grow bed.

Use a check valve to prevent backflow (and save yourself from getting wet). A check valve is an inline device that only allows water flow in one direction.

Out of the fish tank into your hydroponic system via tubing, or vice versa by pulling on its handle with your finger. 

Inline means that it attaches between components or products; thus, if you buy an inline check valve, it will be hooked between two pieces of equipment rather than inside them both.

Use a siphon to get the water from one place the grow bed to another place in line with it through another component such as a filter or pump: 

Add An Air Pump To The System

Place the air pump in the grow bed and attach it to a timer. The air pump should be powered by electricity and attached to a timer so that you can control when it runs. 

You’ll want to run your air pump for at least two hours per day so that all of your plants get enough oxygen and clean water for optimal growth and health.

Root rot is a common problem in hydroponics that can be caused by overwatering, poor ventilation, and other factors. To prevent this issue, check out our expert advice on avoiding root rot in hydroponics and keep your plants healthy.

Adding Plants And Fish

A recirculating hydroponic system can be thought of as a big aquarium. You’ll need to add plants and fish at the same time, so you should plan your tank’s layout carefully. Be sure that there are enough places for both the roots of the plants and fish to grow.

Planning for Plants and Fish in a Recirculating Hydroponic System

Plant selectionChoose plants that are well-suited to hydroponic growing, such as leafy greens, herbs, and small fruiting plants.
Fish selectionSelect fish species that thrive in an aquaponic environment, such as tilapia, trout, or catfish.
Tank sizeChoose a tank size that is appropriate for both your plants and fish. Plan for at least 10 gallons of water per fish, and consider the maximum size of your plants at maturity.
Tank layoutPlan the layout of your tank carefully to ensure that there is enough space for both plants and fish to grow. Consider vertical space, as well as horizontal.
Nutrient balanceEnsure that the nutrient balance in your system is balanced for both plants and fish. Fish waste provides nutrients for plants, but needs to be balanced with other nutrients to prevent overgrowth of algae or other issues.

Maintain Optimal Water Quality

One of the best ways to ensure consistent, healthy growth is to keep the water quality in your system optimal.

Check pH and temperature regularly. You’ll need to test your water on a regular basis ideally once per week to ensure that it’s within the correct range (pH between 5-6 and 7-7.5; temperature around 78°F). 

If you have an RO/DI unit, check both the inlet and outlet sides so that you can confirm that all components are working properly before use.

Keep water clean. Since plants are rooted directly into their growing medium, they will be exposed more than usual if there’s any buildup of nutrients or other impurities in their reservoir over time. 

A good rule of thumb is to change out 25% of your solution every two weeks; this will help keep things from getting too stagnant while also giving you a chance to inspect any issues with algae growth or bacterial infections (which could be caused by dirty equipment).

Add CO2 if needed for better photosynthesis results

A hydroponic greenhouse can provide you with fresh, healthy produce year-round, but building one can be a daunting task. Our guide on building a hydroponic greenhouse offers expert advice on everything from selecting the right materials to choosing the best crops for your climate, so you can get started with confidence.

Observe Your New System Regularly

Now that you have a system up and running, there are some key things to remember as you monitor your system.

First of all, observe the pH levels of your nutrient solution every day to make sure that it remains in an ideal range for optimal plant growth.

Second, observe the temperature levels of your nutrient solution every day to ensure that it stays within a safe range for fish and plant health.

Thirdly, check on daily water level changes and observe any leaks or other problems with your system. 

This may require additional maintenance or repairs by you or a professional at some point in time so pay close attention!

Finally, keep records of all observations with each successive batch of plants (i.e., “Plant 1” was grown on March 10th; “Plant 2” was grown on March 13th; etc.). 

This will help make future adjustments easier because they will be based off historical data rather than guesswork alone–you should also keep records such as this so they can be used when sharing information with friends/family members who might want to build their own recirculating hydroponics systems later down the line!

Key Observations for Monitoring a Hydroponic System

pH and nutrient levelsRegular checks of pH and nutrient levels are important for optimal plant growth. Keep a log of readings to track fluctuations over time.
Signs of plant stressWatch for symptoms like leaves drooping or changing color, as these may indicate a problem with the plant’s environment or nutrient uptake.
Pest and disease inspectionRegularly inspect plants for pests and diseases, such as spider mites, aphids, or root rot. Address any issues immediately to prevent further spread.
Water levelsMonitor water levels and top off the system as needed to ensure plants receive adequate hydration.
System component maintenanceKeep system components clean to prevent buildup of algae or other debris, empty the reservoir and clean it frequently, and inspect all parts regularly for signs of wear or damage.


I hope that you have learned a thing or two about how to build your own recirculating hydroponic system. It’s not as hard as it sounds and with the right materials and know-how, it can be done easily! 

You will be able to grow fresh organic food year-round from this new system in just a matter of weeks. The only thing left for you now is decide which plants would work best in such an environment. 

Further Reading

For more information on building recirculating DWC systems, or deep water culture systems, check out the following resources:

Bitponics: A comprehensive guide to building a recirculating DWC system that includes a materials list, step-by-step instructions, and tips for maintaining your system.

Soak and Soil: A detailed article on everything you need to know before building a recirculating DWC system, from choosing the right container to troubleshooting common problems.

Grower Today: An instructional video that walks you through the process of setting up a recirculating DWC system, from assembling the components to testing the pH and nutrient levels.


How much space do I need for a recirculating DWC system?

The amount of space you need for a recirculating DWC system depends on the size of your container and the number of plants you want to grow. A 5-gallon bucket DWC system can fit in a small space, while a larger system may require a dedicated room or greenhouse.

What types of plants can I grow in a recirculating DWC system?

Recirculating DWC systems are suitable for growing a wide variety of plants, including leafy greens, herbs, strawberries, and even some fruiting plants like tomatoes and peppers.

How often do I need to change the water in a recirculating DWC system?

While the water in a recirculating DWC system doesn’t need to be changed frequently, it’s important to monitor and maintain a healthy pH and nutrient balance. Some growers recommend changing the water every 2-3 weeks or whenever the nutrient levels are depleted.

How do I maintain the pH and nutrient levels in a recirculating DWC system?

Maintaining the pH and nutrient levels in a recirculating DWC system requires regular monitoring and adjustment. You can use a pH meter and nutrient testing kit to measure and adjust the levels as needed.

What are some common problems with recirculating DWC systems, and how do I fix them?

Common problems with recirculating DWC systems include clogged air stones, root rot, and nutrient imbalances. If you encounter any of these issues, refer to the instructions for your specific system, or consult a hydroponic expert for advice on how to fix the problem.