Recirculating Deep Water Culture (RDWC or DWC) | Hydroponic Grow Method

Recirculating Deep Water Culture

Much like it’s cousin, the bubble bucket, the recirculating deep water culture system (RDWC, better known as DWC) quickly grows plants in a near ideal environment. The main difference is that the system supports multiple sites and allows you to grow a much larger crop of the same plant with far easier maintenance.

DWC systems contain:

  • A central reservoir
  • An optional control reservoir
  • Multiples plant pots linked via piping
  • Air stones in each plant site, and the reservoirs
  • A pump to recirculate the nutrient solution throughout the system

Due to all the parts, DWC is much larger and more expensive to setup that bubble buckets, but due to the shared resources, maintaining nutrients on all plants becomes far easier.

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Why should you grow this way

For hungry plants, DWC grows them about as fast as you can get, so it’s ideal to maximize yield per time frame. Also, because of the shared everything system, you can minimize maintenance time by tending to all the plants simultaneously with regards to nutrient changes. Maintenance becomes trivial with only one system to keep watch of… and you need to keep watch on it. All pots are connected so an issue affecting one pot likely spreads to the others very quickly.

How to grow this way

Buying RDWC pre-made

Commercial DWC system
Masterful Photoshop Skills

While the many kits on the market make getting started very easy, they tend to thin the wallet. In part, the many bits that make up the DWC system drive the price, but mostly the convenience dictates what people will pay, especially if you are growing a premium crop that you cannot afford to fail with. The most reasonably priced system Amazon has to offer is a kit that contains a series of things you can make yourself (and comically poor photo editing). You’d need to perhaps add a larger reservoir and float valve to fill the control tank, but otherwise, it’s a solid start. Better systems exist, but the price trends upwards quickly. If you’re growing for profit or to minimize time, this may be worth it, though.

DIY RDWC/DWC

Building your own requires a working knowledge of how water levels work, and the ability to work with plastic piping. You’ll need:

  • A control tank that is the same height as the grown buckets.
  • A large air pump, manifold,  and tubing to move the air around
  • A large-ish pump to push nutrients around
  • An optional supply reservoir. This will be elevated from the control tank and feed into it via gravity. This will need its own air stone off the main air pump or its own air system
  • Several grow buckets with
    • A bulkhead fitting or grommet on the bottom so water and nutrients can move between tanks. This should be as large as is practical. Round, 5-Gal buckets limit this to about a ¾” rubber grommet and using vinyl tubing (due to the curve). Square/rectangular buckets can easily use a 2” bulkhead fitting for much better performance, but on-line pricing for the buckets is all over the place ($30 a bucket?). If you can find suitable containers locally (bulk food storage containers are your best bet), you can get the bulkhead fitting and attach it to 2” hose using a barb fitting. Probably some hose clamps as well.
    • An inlet grommet or bulkhead fitting. ¾” should be fine
    • An airstone
    • Basket to hold the plant filled with grow media of your choice

Simply mix your nutrients, and run the pumps continually. Transplant your seedlings into the grow media with the roots touching the liquid. Within a day or two you should start to see growth.

3 years ago