How to Create a Deep Water Culture Hydroponic System
Learn how to set up a simple DIY deep water culture hydroponic system at home
Deep water culture (DWC) also known as hydroponics may sound like a complicated method of growing plants, however, it is not as complicated as it sounds and does come with its own advantages. Some of these advantages are that you are able to grow your own healthy, fast growing produce that requires minimal maintenance and no fertilization.
DWC is a system of growing plants in small net pots without soil. The roots of the plant will then grow from the suspended net pot without restraint, and reach down to the nutrient rich reservoir where they’ll eventually submerge themselves in the water.
If you live in a predominantly cold environment or maybe you want to grow a particular plant during winter, DWC is a perfect indoor option, so if you’re ready to create your very own DWC system at home, here’s how to do so.
3 Inch net pots
Nutrient solution and pH adjusters
Rockwool and hydroponic clay pebbles
5 Gallon container and water
6500k grow lights
Air pump, air tubing and air stone
Drill with 3 inch drill bit
1. Preparing the materials
To get started you will need a plastic container to hold the water, you can purchase 5 gallon totes or buckets online or at your local home depot, these are relatively easy to find and inexpensive. When purchasing your water container try to find ones that are rated as food safe.
If you opt to purchase a tote, look for the recycling number on the tote. The number ‘5’ on the container means that the plastic used to make the container is made out of polypropylene and is not as heat tolerant as number ‘2’, which has a higher density.
Since you are growing indoors, your containers will not be exposed to high heat and therefore it is generally considered safe. However, if you are growing outdoors or in a hot environment try to purchase a number ‘2’ or ‘4’ tote as they are more heat tolerant which makes them safer.
In general the numbers, (1,2,4 and 5) are considered food safe plastic.
You will also need a few 3 inch net cups to hold your plants.
To add holes to your tote container you will also need a 3 inch hole saw drill bit. This is to create the openings in the tote to fit your net cups.
If you choose a container with a thinner lid cover, you may be able to cut out the holes with a knife. If not, a hole saw does a pretty good job.
Once you’ve cut the desired amount of holes that you need, place your net cups inside to ensure that they fit comfortably.
When doing DWC you will also need to use an air pump to make sure that the roots of the plants have a good supply of oxygen. These can be bought on Amazon and are also inexpensive. Try to purchase an air pump that is good for about 80 gallons of water or more, with two outlets so you can run tubing to two systems if you need to.
Drilling the tote
Now you need to make one more hole in the tote, take your drill and from the inside of the container, drill a small hole through the side and top section of the tote.
This hole will be used to run the tubing from the air pump down into the water. You can drill two holes if you are planning to run both air stones into the tank.
2. Adding the water and nutrient solution
It’s now time for you to add water in the container. When creating a DWC system plain water alone is not sufficient to sustain the plants, you will need to add nutrients to water.
When selecting nutrients look for those that are specific to your plants, if you are growing fruiting plants try to find the right formula blend for that.
Depending on the amount of water and brand of your nutrient solution, the amount to be used may vary. In this article the nutrient solution is a three-part formula that needs to be weighed out. For some three-part formulas you may have a measurement of 2.4 grams of master blend to every gallon of water, 1.2 grams of epsom salt per gallon of water and 2.4 grams of calcium nitrate to every gallon of water. Try to use warm water as this will allow the nutrients to dissolve better.
You will need to purchase a food scale to ensure that the weight of your formula is correct. To measure correctly, try to mix one gallon at a time using old containers. It’s easier for you to do one gallon at a time instead of mixing it all at once.
3. pH adjustments
Once you have your nutrients added to the water, you will need to test the pH and adjust it either up or down. Try to get your water in the 5.5 to 6.5 range or your preferred sweet spot.
4. Connecting the pump
Now it’s time to connect the pump, what you want to do is to thread the tubing through the holes you made at the side of the tote.
Once you’ve done that, attach the air stone.
Make sure to place the pump above the water level, you can place it on a shelf that's resting above the tote, then plug in the pump.
At that moment you should have a nice flow of air with all the bubbles.
5. Transferring the plants
Before transplanting, seeds should be placed in rockwool cubes which is a form of growing substrate, to begin their growing process. This is the first step to take before building your DWC system.
Once the seedlings become ready for transplanting, place the young plants with the rockwool into the net cups and fill in the empty space in the cup up with hydroponic clay pebbles.
The clay pebbles help to keep the rockwool from moving around, they also block the light from hitting the water under the plants.
Take the net cups and rest it in the tote cover in the holes you cut out, and then put the lid on top of the tote container with water.
Light is good for the plant but not for the water as you do not want to encourage algae to grow. Try to block the light out from the water in whichever way you can, or leave the clay pebbles to do that.
In addition to water and oxygen in the tote, the plants will need light to survive and thrive. The lights used should be close to the plants as possible without burning them.
You want the plants to grow short and stout rather than tall and leggy. The closer the plants are to the light source the better. Try to use lights to simulate the daylight along with the natural lights you may be able to get from a window.
If you’re growing in a basement or garage, your lighting needs will be a bit more demanding so take into consideration where you’ll be growing your plants.
In two weeks time after planting you should be able to see your plants thriving. This system is better than the kratky method for fruiting plants such as tomatoes, cucumbers and peppers. Remember when you are trying this system out, try to adjust it to the needs of your plants or for your own unique growing environment.