Vertical Recirculating Deep Water Culture System (5x5ft)



How does one best document a hydroponics system? We don’t know! We will will learn as we try. Let’s give it a shot and start with photos, so you can see what we are talking about.



This system is a Recirculating Deep Water Culture hydroponics system. “Deep water” means that the plants' roots sit in the water all the time. “Circulating” means that the water circulates through the system, bringing oxygen and nutrients to the plants on an ongoing basis. It is intended for your backyard, or some other place outdoors in the sunshine. It takes:

  • about 5 ft times 5 ft of floor space, and is
  • between 6 and 9 ft tall, depending on some options (like solar).

As you can see in the photos, the system has a sturdy, central wooden frame, made from common (and cheap) 2x4’s. Its arms are made from (also cheap and sturdy) plywood sheets. They hold up eight horizontal PVC pipes, four on each side, that hold the growing plants, and through which the water circulates. The water enters a growing pipe on one side, and spills over into a thinner PVC pipe on the other side, which leads the water into the next horizontal growing pipe on the other side, a little bit further down. The spillover level is set so that the plants' roots can reach the water easily and the plant doesn’t drown.

A common storage box with some extra holes serves as a reservoir for the water. The reservoir also contains a submersed pump, which pumps the water up the vertical pipe from where the water enters the first horizontal growing pipe through a thin plastic tube. The water ends up back in the reservoir once it has left the lowest growing pipe. This single path of the water through the system makes it easy to detect problems, should there be any.

The plants grow inside little net pots placed into holes cut into the horizontal growing pipes. Six of the growing pipes are for larger plants, so the holes for the net pots are relatively far apart. Two are for younger and smaller plants that can be placed more closely together.

(Of course, you could build this differently, based on what your needs are, like with anything else we describe here. We only document what worked for us. And if something works better for you, feel free to submit a pull request.)

There are some options, which you may or may not want to install:

  • towards the bottom, the system has room for a germination tray in which seeds can be germinated until they have grown enough to be placed in the net pots; this works well when it is warm outside, including at nights. When it’s not warm enough, you need to germinate indoors otherwise your seeds won’t sprout.
  • at the top, there is room for a solar panel attachment, which produces enough energy to power the pump circulating the water.

This system is designed as a collection of modular parts. So we document it one part or one assembly at a time. This allows us to improve the system one part at a time as well, without disrupting the rest of the system very much.

Systems model

  • System model – overview over how the system works: inputs, outputs, catalysts etc.


Here’s all the info you need to build the system:


Have the system built? Time to grow some plants! Here is how: