What Is Deep Water Culture Hydroponics?

deep water culture hydroponicsDeep Water Culture (DWC) is definitely among one the simplest of the six hydroponic systems yet the most effective type for growing plants hydroponically. Even though the concept is simple, there are many ways to use and build a deep water culture using different materials and a very inexpensive system to build.

Deep Water Culture (DWC) hydroponics is a method of growing plants in aerated water where the roots are suspended in an actively oxygenated solution full of nutrients and water 24/7, rather than planted in soil. By “deep”, it means that the roots must be submerged deep in the water.

There are three critical parts of this solution:

  • Oxygen: Because the roots are submerged in water and not soil (which has gaps and holes where air resides), the water needs to be well oxygenated to prevent the plants from drowning. This is accomplished with an air pump and air stone.
  • Water: Think of this system as if you’re growing in soil and permanently watering your plants – this is one of the reasons growing hydroponically is so beneficial – you never need to ‘water’ again.
  • Nutrients: Good quality soil contains all of the micro and macro-nutrients that a plant needs to survive and thrive.  Because we have no soil, we need to supplement the oxygen-rich water with nutrients so our plants can grow.

This method is called Deep Water Culture for two reasons.

  • You grow with a reservoir that can hold a decent amount of water.  More water means more stability in your nutrient solution, which means less monitoring and maintenance for you!
  • How much of the root mass do you submerge in the water? In deep water culture, most of your plant’s root system is submerged 24/7.

DWC eliminates many of the drawbacks of growing plants in soil and results in faster plant growth and larger crop yields.

Types of DWC Systems

The Kratky Method

krathy hydroponics methodThe Kratky Method is the Deep Water Culture System without the air pump as well as part NTF System. It’s a water culture system because the plants hang above the water/nutrient reservoir the roots hang down into. It’s also part NFT System because, like NFT Systems, there is a gap between the basket holding the plant and the water the roots sit in. This gap is an air pocket and is supposed to replace the air pump in a standard water culture system. This is a passive system with no electricity used. 

The key here is to leave an air gap between the roots and the surface of the nutrient solutions. As the plants grow and the roots get longer, the plant drinks up some of the water which lowers the water level and leaves an air gap. This means parts of the roots are submerged in the waters while the other parts are exposed to the air.

The Recirculating Deep Water Culture System – RDWC

Recirculating Deep Water Culture SystemThe traditional DWC system cannot be scaled up – that’s when there is a need for an RDWC. You can have many buckets/containers linked to a central reservoir in recirculating deep water culture. The oxygenated nutrient solution passes through each plant before getting back to the tank. The system works in a similar way such as a cross between a deep water culture and a flood and drain system, but the nutrient solutions never drain/get out of the system.

In the RDWC system, each bucket can hold around 1 to 3 plants. Some can even lock six or more plants depending on the variety. But it can bring a threat of the roots clogging the air stone, and less oxygen.

Bubbleponics

bubbleponicsBubbleponics is another type of DWC system that is the same as the regular type but with only one difference – the addition of a water pump inside a reservoir. The purpose of the water pump is to supply oxygenated water to the top of the net pots.

Bubbleponics is the ideal method at the beginning phase of your plants when the roots are still short, and cannot fully reach the water below. 
Providing nutrients and water at this stage helps the roots grow faster, and when they can sink deep into the reservoir’s nutrient solution, there is no advantage anymore. 
It aids the seedlings’ roots to grow faster.

Advantages of Deep Water Culture Systems

DWC systems are popular and a good way to get started with hydroponics. It’s one of the easiest to set up. The only system that is simpler is a wicking system.

Here are some of the advantages of Deep Water Culture systems:

  • DWC systems are easy to set up and only require a few parts.
  • The only moving part is an air pump, which is easy to configure.
  • Low maintenance once you set it up as long as it’s frequent.
  • Plants grow much faster compared to growing plants in soil.

Disadvantages of Deep Water Culture Systems

There are some issues with this type of system that can cause you problems. These can, however, be overcome by careful setup and maintenance.

Here are some of the disadvantages of Deep Water Culture systems:

  • In small systems, pH, water level, and nutrient concentration may fluctuate wildly
  • In small systems, the opportunity to over or under-calibrate is VERY easy due to small scale
  • If you have an electricity outage or a pump failure, your roots may “drown” in low-oxygen nutrient solution
  • It can be difficult to maintain a consistent water temperature

Which Plants to grow in DWC

The plants most suitable to grow with Deep Water Culture systems are plants that do not produce flowers and some herbs.

  • Lettuces
  • Tomatoes 
  • Annual vegetables 
  • Peppers
  • Basil 
  • Okra
  • Kales 
  • Sorrel 
  • Bok choy 
  • Chard
  • Larger fruits like Squash even though they take a bit more effort

These plants grow fast and healthy.

Happy Growing

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