Deep Flow Technique (DFT) Hydroponic Systems
Leah Soto | Pure Greens LLC
Deep flow technique (DFT) is a way to grow plants without soil. Plants sit on floating rafts, and their roots hang down into a shallow stream of water filled with nutrients. As a result, they grow strong and healthy in a clean, controlled space.
DFT is great for big farms, city gardens, and places that need to grow food all year long. It uses less space and water than regular farming and helps make sure people have fresh food nearby. As more people live in cities, DFT helps grow more food where it’s needed most.
Many farmers use deep flow systems to grow herbs and leafy greens in high-tech greenhouses. These farms are clean, safe, and built for the future.
What Is Deep Flow Technique?
Deep flow technique is a hydroponic system in which growers place crops on floating rafts. These rafts sit on top of a shallow bed of water filled with nutrients. The roots grow down into the water, soaking up everything the plant needs to grow strong and healthy.
This method differs from other hydroponic systems like NFT (Nutrient Film Technique) or DWC (Deep Water Culture). NFT uses a thin water stream that runs over the roots, while DWC keeps the roots fully submerged in deep water. DFT strikes a balance between the two, with a constant but shallow layer of water that stays in motion.
One significant advantage of DFT is that it's more stable. The water acts like a buffer, keeping the plants safe if the power goes out or a pump stops working. It also holds heat better, which helps keep root temperatures steady.
The system includes air stones or special bubble makers to add oxygen to the water. This component is important because plant roots need both water and air to stay healthy. Constant water flow and aeration also keep algae and harmful bacteria from building up.
Because it uses recirculating water, DFT is efficient and uses less water than traditional farming. It’s also easy to scale, making it a smart pick for greenhouses, vertical farms, or even school gardens.
DFT vs. Other Hydroponic Systems
When comparing hydroponic systems, the deep flow technique hydroponic system stands out for its balance of simplicity and reliability. It differs most from NFT (Nutrient Film Technique) and DWC (Deep Water Culture), two other popular methods.
In an NFT system, a thin stream of water flows over the roots, delivering nutrients as it passes. It’s efficient but risky—plants can dry out quickly if the water stops flowing. DWC systems, on the other hand, fully submerge plant roots in deep water. These setups offer more protection but use more water and are more complicated to manage at scale.
DFT finds a middle ground. It uses a shallow layer of water—deeper than NFT but not as deep as DWC—that stays in motion. This constant flow keeps nutrients and oxygen moving, which helps plants grow strong. If a pump stops working for a short time, the plants are less likely to be harmed than in NFT.
DFT systems are especially good for leafy greens, herbs, and other fast-growing crops. Their floating raft design makes it easy to plant, harvest, and clean between cycles. Plus, the system is scalable, making it a top choice for commercial greenhouses and vertical farms.
| Feature | Deep Flow Technique (DFT) | Nutrient Film Technique (NFT) | Deep Water Culture (DWC) |
|---|---|---|---|
| Water Depth | Shallow, stable layer | Thin film over roots | Deep, fully submerged roots |
| Oxygenation Needs | Moderate (uses air stones or bubble diffusers) | High (low flow = low oxygen) | High (requires strong aeration) |
| Resilience to Failures | Medium (buffer from water layer) | Low (plants dry quickly if the pump fails) | High (roots stay submerged) |
| Crop Types | Leafy greens, herbs, baby greens | Small, fast-growing greens | Great for larger, water-loving crops |
| Scalability | Easy to scale with modular rafts | Scales well but can clog with roots in longer systems | Scalable but harder to manage in large commercial systems |
| Maintenance Level | Moderate (cleaning channels and rafts) | Low to moderate | Moderate to high (cleaning and monitoring water levels) |
Components of a DFT System
A deep flow technique system combines several parts to grow healthy plants.
At the base are growing channels, also called raceways. These long, shallow trays hold the nutrient-rich water. They’re usually made from food-safe plastic and are sometimes insulated to help keep the water at a steady temperature. The layout can be adjusted to fit greenhouses, schools, or even community gardens.
Floating rafts sit on top of these channels. They are often made from materials like HDPE (high-density polyethylene) or polystyrene. Each raft has holes that hold net pots—small containers that support the plants. The spacing between each hole can be changed depending on what’s being grown. Leafy greens need less room, while larger plants may need more space to thrive.
Under the channels, pumps move the water through the system. Reservoirs store the water and nutrients. Aeration tools like air stones or micro-bubble diffusers add oxygen to the water. All of these parts work together to create a balanced, easy-to-manage system that keeps plants growing strong from start to finish.
Pros of Deep Flow Technique Hydroponics
The deep flow technique offers several big advantages for growers of all sizes. One major benefit is thermal stability. Because the water holds heat, plant roots stay at a steady temperature. This helps crops grow more evenly—especially in greenhouses.
DFT systems also use water very efficiently, recirculating it repeatedly and wasting very little. This makes DFT a smart choice in places where water is limited or expensive.
Another key strength is resilience. If the power goes out or a pump stops working, the shallow water bed gives plants time to survive without drying out right away. That extra buffer can make a significant difference in avoiding crop loss.
Finally, DFT systems are scalable and modular. Whether you’re running a large commercial farm or setting up a school garden, the system can be adjusted to fit your space and goals. It’s a flexible, sustainable way to grow food.
Challenges and Limitations
While DFT systems offer many benefits, they also come with a few challenges. One of the biggest is weight. Since the system holds a lot of water, it can be heavy—making it harder to use in rooftop gardens or vertical farms where weight matters.
Maintenance is another concern. Over time, algae and biofilm can build up in the channels and on the rafts. These need to be cleaned regularly to keep the system running well and the plants healthy. Some setups can be harder to access for deep cleaning or repairs.
DFT systems also require careful control of water flow and oxygen levels. Plant roots suffer if the water isn’t moving well or has too little air. Tools like air stones and regular monitoring help fix this, but it still takes time and attention.
Even with these limits, DFT remains a strong option—especially when paired with smart planning and routine care.
| Challenge | Solution |
|---|---|
| System weight limits rooftop use | Use lighter materials and support structures designed for heavier loads |
| Algae and biofilm buildup | Clean channels and rafts regularly; use light-blocking covers |
| Hard-to-reach areas for cleaning | Design systems with removable parts and easy access points |
| Maintaining oxygen levels in water | Install reliable air stones or micro-bubble diffusers; check regularly |
| Precision limits in irrigation control | Use timers and flow sensors to fine-tune nutrient delivery and flow rate |
Ideal Crops for DFT Hydroponic Systems
Deep flow technique hydroponic systems work best with crops like leafy greens, herbs, and baby greens. These plants grow fast, have small root systems, and do well in water-based setups. Many growers use DFT to grow lettuces and salad greens such as romaine, butterhead, and arugula.
With a few changes—like using stronger rafts or giving plants more space—DFT can also grow larger crops. Some growers have success with cooking greens like kale, bok choy, and Swiss chard. These plants are a bit heavier but still thrive in the steady, oxygen-rich water DFT provides.
DFT is a solid choice for growers who want clean, healthy crops and a simple system. It’s easy to manage and works well with many of the greens people eat every day.
Commercial & Educational Applications of DFT
Deep flow technique systems are used in both big farms and small learning spaces. In commercial greenhouses, DFT helps grow lots of fresh greens quickly and with less water. It's a good fit for farmers who want to grow healthy food all year long.
DFT also works well in schools and community gardens. The system is easy to set up in smaller pieces, so students and groups can learn how plants grow without soil. It’s a hands-on way to teach science, farming, and the importance of fresh food.
Because DFT works best in controlled spaces, it's often part of larger indoor farming setups. These are called controlled environment agriculture, or CEA. DFT is a smart, flexible way to farm for a city market or a school lunchroom.
DFT Maintenance Best Practices
Keeping a deep flow technique system running smoothly takes regular care and good records. It's important to track things like electrical conductivity (EC), pH, water temperature, and dissolved oxygen (DO). These numbers help you know if your plants are getting what they need.
Cleaning is also key. Rafts should be rinsed between plantings, and channels should be scrubbed or flushed to stop algae or buildup. Aeration systems, like air stones or bubble lines, should be checked often to make sure they’re working well and giving roots enough oxygen.
Good maintenance keeps the whole system clean and helps prevent plant problems before they start. Growers should follow strict sanitation and monitoring practices to grow safe, healthy crops. These habits can help DFT growers keep their systems running strong and their harvests consistent.
Partner with Eden Green for Advanced Hydroponic Solutions
At Eden Green, we help partners grow fresh, clean produce with powerful hydroponic technology. Our high-tech greenhouses are built for year-round production. Our herbs and leafy greens are grown without soil or pesticides.
We offer custom solutions for retailers, food service companies, and private label partners. From planting to packaging, our systems deliver high-quality crops quickly and efficiently. Whether you're starting small or scaling up, we can help you build a smarter, more reliable food supply.
If you're ready to grow your business with sustainable hydroponics, we’re here to guide the way. Contact Eden Green to explore partnership opportunities and get started.
FAQs
How does the Deep Flow Technique compare to other hydroponic methods?
Deep flow technique uses a shallow layer of water to feed plant roots, offering more stability than NFT and using less water than DWC. It’s a balanced option that works well for leafy greens and herbs, especially in large setups.
What are the main benefits of using DFT systems in commercial greenhouses?
DFT systems are known for their water efficiency, thermal stability, and ability to withstand short power outages. They're easy to scale, making them ideal for commercial growers who want reliable, year-round production.
How do DFT systems integrate with aquaculture systems?
DFT can be part of an aquaponics setup, where fish waste becomes nutrients for the plants. The plants, in turn, help filter the water before it returns to the fish tanks. This creates a closed-loop system that’s both efficient and sustainable.
What are the challenges of maintaining DFT systems?
DFT systems need regular cleaning to prevent algae and biofilm buildup. They also require monitoring of water quality, including pH, temperature, and oxygen levels, to keep plants healthy and systems running smoothly.
How does the temperature affect the efficiency of DFT systems?
Water temperature plays a big role in plant health. If it’s too hot, roots can suffer. If it’s too cold, growth slows down. DFT systems benefit from insulated channels and steady airflow to help maintain ideal temperatures.
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