Deep water culture may sound a bit out there, but it is one of the easiest hydroponic methods to start with. It is also one of the most popular. As a very basic explanation, in a deep water culture system, the roots of the plants sit suspended in water that is oxygenated and full of nutrients. This is a very popular system because it requires very little maintenance once it is all set up, the plants grow extremely fast when compared to growing in soil, there are very few parts needed, and assembly is not that complicated. As with anything, proper maintenance is an absolute must, but once started this can be a great option.
Build Deep Water Culture System (DWCS)
There are a few different ways to build a deep water culture system. Since this book is for beginners, let’s talk about a traditional deep water culture system, as this is the easiest to build. Most of the parts needed for this system can be found online, in a home improvement store, or a pet store. Here is a list of needed items:
- 5 Gallon Bucket, old aquarium, or another large container
- Air Pump
- Air Stone
- Airline Tubing
- Net Pots
- Growing Media (natural clay pebbles)
- Hydroponic Nutrients
- pH Control Kit
Once all of these items are collected, begin building your deep water culture system.
- Connect the air pump to the tubing.
- Connect the tubing to the air stone.
- Place the air stone in the bucket.
- Fill the bucket up with water.
- Properly pH the water. Most plants prefer the pH to be between 5.5 and 6.5. Just make sure that you monitor this number and know that it changes when the plants are in different stages. When plants are growing, the pH needs to be higher; when the plants are flowering, it needs to be on the lower end.
- Add nutrients to the water. There are many options out there for nutrients. Talk to your local garden centre to find the best fit for you. A very simple solution to start with is the General Hydroponics Flora Series. Follow the instructions to mix up varying amounts to use based on the plant’s stage of growth.
- Start your seeds. During this process, it is important to keep light out of the container. It might be a good idea to put duct tape over the sides and bottom of the container to make sure algae does not grow, especially if your container is not dark, to begin with. Place the seed in the plant growth media, and put in the net pot. The roots should begin to develop in about seven to fourteen days.
- Watch in amazement as the roots hit the water and there is an explosion of growth. As long as proper oxygen and nutrients are provided, the plant can live quite well submerged in the water its whole life.
The traditional method is a really good place to start. Once this method is old news and an upgrade is desired, look into creating a recirculating deep water culture system. This system allows multiple buckets to be used to grow the same plant. There is one main reservoir that feeds the nutrient solution across all of the buckets.
Maintaining Deep Water Culture System (DWCS)
There are a few common issues that often come up with this type of system. It does take a while to get the hang of pH, water level, and nutrient concentration. Plus, in a small system, these numbers can fluctuate greatly. Another problem that can arise is a power outage. The roots can “drown” if a pump fails and the solution becomes low in oxygen. The water temperature can be another issue. It is optimal to keep the water temperature below 68 degrees and above 60. The oxygen level begins to drop in higher temperatures, and the plant may get confused into thinking it is moving into fall or winter if the water temperature gets too low.
With proper monitoring and maintenance, most issues can be overcome easily and quickly. The nutrient solution will need to be changed out occasionally. The solution should be changed out completely at least every three weeks. A little more research will likely need to be done to see how often this should be done. It depends on the type of plants that are being grown, the size of the reservoir, and the stage of growth the plants are in.
A couple of other things to watch for are the number of roots submerged in the water and, root related plant diseases. Make sure that no part of the stem or vegetation is ever submerged. It is best to have an inch or inch-and-a-half of the roots exposed above the waterline. Bubbles from the air stone should rise to the top and pop to keep the roots above the water line moist. Also, keep an eye on the plants to make sure they look healthy. Diseases like Pythium can strike and devastate a plant.
It may take a little trial and error to find the best location for this system. Of course, natural light is always best for plant growth. However, maintaining the water temperature could be a bit difficult in direct sunlight, especially if the sun is intense in the yard. This system could be put on wheels and moved around, or placed in a window, sunroom, or greenhouse. If things only work out indoors, artificial lighting options may need to be used.