Hydroponics – The Different Types of Hydroponics Systems You Can Build
Definition of Hydroponics
Hydroponics is the cultivation of plants without the use of soil. The roots of a plant are placed in a nutrient-rich solution. The temperature, humidity, pH and lighting is controlled to make the plants grow to their maximum potential. You can have hydroponics outdoors where you won’t have complete control over temperature, humidity and lighting, though you still have to monitor pH.
There are some definite advantages to hydroponics. Hydroponics can be used in places where traditional agriculture is not an option. Places like deserts, cold regions and urban areas. It takes less water, no weeding and there few if any pests. Crop yield is usually higher and you don’t have to worry about crop rotation.
There are hundreds of different types of hydroponics systems each with pros and cons. They can be set up with or without support medium for the roots. The systems are classified as either open (nutrient solution is not reused) or closed (nutrient solution is recovered). Some systems can be pretty much just set and forget while others take constant observation. These hydroponics systems can be put into one of six different categories:
1. Aeroponic Systems
This is a system that, as the name suggests, uses air as the growing medium. Plants are placed with their roots hanging down in the air and they are misted with nutrient solution at regular intervals for a few seconds. A timer is used to control the cycle. Another form of this is to place your plants in a tube vertically and allow the nutrient solution drip from the top plant down to subsequent plants. These are generally closed systems.
2. Drip Systems
This system uses an aggregate to support the plant roots and as this name suggests, the nutrient solution is dripped onto the base of the plant. A pump placed in a reservoir and controlled by a timer is used to drip solution every few minutes. In a closed system, the runoff is directed back to the reservoir. In an open system, the runoff is just wasted. It is kept to a minimum though, so more precise control of the pump is required. A closed system requires closer observation to ensure proper pH and nutrients.
3. Ebb and Flow Systems
This system also uses aggregate to support plant roots. It works by temporarily flooding a tray the plants grow in and letting the tray drain back into a reservoir. Again, a pump is placed in the reservoir and a timer controls the fill and drain cycle. The cycle is completed several times a day, depending on tray size and the plants that are grown. These systems are closed systems.
4. Nutrient Film Technique(NFT) Systems
This is a very popular method and what most people think of when they hear the term hydroponics. It is a system that uses a very thin film of nutrient solution to supply plant roots with what they need. The solution is pumped up to one end of a tray, gutter or tube and flows to the other end. The tray is usually on a very slight slope which allows for the “film” with very little solution being pumped. Most of the NFT systems will not have any grow medium and will be closed systems.
5. Water Culture Systems
A water culture system is very simple. Plants are usually placed in mesh pot of some kind and put in a platform that floats on the surface of growing solution. An air pump and air stone is all that is needed for this type of system. These are very easy to make and very inexpensive. There are not too many plants other than lettuce that will do well in these systems however.
6. Wick Systems
A wick system is the simplest type of hydroponic system you can make. This system uses an aggregate of some kind, usually one that will absorb a lot of moisture. There is a grow tray or pot and there is a reservoir. A wick is run from the reservoir up to the plant. The wick will draw the solution up into the growing medium and keep it moist and keep the plant fed. A wick system is a passive system and the only maintenance is to add nutrient solution from time to time.
A simple way to make one of these systems is to cut about 1/3 off the top of a plastic drink bottle. You then drill or poke a hole in the center of the cap and run a wick though it. Fill the bottom of the bottle with grow solution (water) and place the top on it with the cap down and the wick in the solution. You now have a place to put a grow medium like perlite, coconut fiber or potting mix. Just add a plant.
The Difference Between Hydroponics and Aquaponics
Aquaculture is the growing of aquatic animals like fish or aquatic plants like seaweed. We defined hydroponics as growing plants without soil. When you cross the two you get what is commonly referred to as aquaponics. You just replace the hydroponics solutions with water from the fish tank.
All aquaponic systems are hydroponics systems, but not the other way around. In an aquaponic system the nutrient solution is supplied by the aquatic life. Many people are raising fish and using the fish to supply their plants with a nutrient solution. This feeds the plants and filters the water for the fish. It is a symbiotic relationship between the fish and the plants.
All the above types of system could be aquaponic systems, however, they would have to be closed systems.
The popularity of hydroponics has increase dramatically in recent years. Many people are experimenting with both indoor and outdoor hydroponic gardens. Vertical hydroponic farming is what most commercial urban farming companies are using. Many of the homemade hydroponic setups are the results of the vertical farming industry. There are a multitude of different design ideas. Just do a search online for homemade hydroponics and you will get thousands of results.
A homemade system can be as simple as the soda bottle I mentioned earlier or can get really complex. They can be setup outdoors and use the natural sunlight or indoors and use artificial lighting. If you have a fresh water aquarium, you have a great start on an aquaponics system. You could just float a piece of Styrofoam with holes for pots grow lettuce like plants. Although the fish might tend to eat the plant roots. It might be easier to set a planter on top of the aquarium and set up a drip system.
I have a aquaponic setup in my greenhouse. I grew hydroponic tomatoes, peppers, cilantro and okra in it last winter. The tanks are 275 gal plastic totes that I bought from a bakery. I just cut the top off and wrapped with insulation. The grow bed is a plastic animal feed/water trough I got at Tractor Supply. You can see the setup in the pics below.
The first picture below is of the initial setup. This was in Nov 2015. You can see the two tanks on the left with the grow bed above the one tank. The second picture is two months later. The third is at the end of March. As you can see I added a grow light and a propane heater. The heater was just to keep me warm when I was out there, it didn’t keep the greenhouse warm.
I was getting tomatoes this spring before most people planted theirs. They lasted until mid summer when it got really hot. I probably got two bushels of hydroponic tomatoes from my aquaponic setup..
Although you can’t see them in this picture, I was getting peppers from those two plants from February until October. I picked about 5 or 6 per week.