Hydroponic gardening is an efficient way to get a large return out of your investment. Hydroponic systems use water and nutrients efficiently and also encourage faster growth rates, which, in most cases, leads to larger yields. Before you set up a hydroponic garden, you’ll want to do a little research about the systems available out there.
Every hydroponic system operates on the same principal of gardening without the use of soil, but each has its own quirks. If these quirks are properly understood, you’ll be able to more effectively take advantage of all hydroponic gardening has to offer. The following hydroponic systems are all commonly used by hobby growers:
Top Feed Systems
A top feed hydroponic system is a system in which a feed line is directly run to the base of each plant. A pump, normally controlled by a timer, intermittently supplies the plants with nutrient solution.
A top feed system can be set up as either a run to waste system (the nutrient solution goes to waste after feeding the plants) or a recirculating system (after feeding the plants, the nutrient solution is collected in a reservoir to be reused again later). Top feed systems are very popular for commercial hydroponic tomato growers, especially those using stonewool as the medium.
Tips for Top Feed
Having a properly sized pump is crucial when setting up a top feed system. The key is balance; you want a pump that is large enough to provide water to the farthest plant site is needed, but it cannot be so large that it heats up the nutrient solution as soon as it is turned on.
Installing a main line for water distribution and smaller diameter lines for the actual feed lines will help make good use of the given water pressure. To maximize efficiency, inline valves can be installed at each plant site that will allow the flow rate to be controlled for each individual plant.
A plant’s size, genetic makeup and position in the garden can affect its nutrient uptake, so the ability to adjust the flow of nutrient solution is crucial for optimizing growth. Another tip for top feed systems is to build the trays at a very slight angle toward the return line. This will ensure no sitting water remains in the tray between feedings. Sitting water can harbor pathogens and create a whole world of moisture-related problems in the fruiting/flowering stage of growth.
Flood and Drain Systems
Flood and drain, also known as ebb and flow, hydroponic systems are another popular choice among both commercial and hobbyist gardeners. A flood and drain system uses a table or trough that is flooded with nutrient solution for a given period of time and then drained. Although a second pump can be used, most flood and drain systems use gravity to return the nutrient solution to the reservoir.
Tips for Flood and Drain
One important aspect of setting up a flood and drain system is the overflow valve. The overflow valve is what sets the flood height in the tray and also allows the nutrient solution to return to the reservoir instead of overflowing the growing tray. It should be twice the diameter of the input line from the pump. For example, if the pump is delivering nutrient solution through a 0.5-inch line, the overflow valve should be at least one inch in diameter. It is also a good idea to install a screen over the top of the overflow valve to guarantee no medium or plant material gets into the reservoir or clogs the opening.
Nutrient Film Technique Systems
Nutrient film technique, or NFT, is a system that supplies a plant’s roots with a continuous flow of nutrient solution through a series of tubes or gutters. The “film” refers to the thin layer of nutrient solution that covers the bottom of each tube or gutter. To make a film of nutrient solution, these systems use a low volume pump to create a continuous trickle. The tubes or gutters are positioned at slight angles, allowing gravity to return the nutrient solution to the reservoir or the subsequent tube or gutter.
Tips for NFT
When considering using a NFT system, think about the size of the plants to be grown. Finishing large plants in NFT systems can be difficult because large plants have large root masses. Oversized roots in a NFT system can be troublesome and may clog tubes or plug gutters.
Another concern when setting up a NFT system is pump size. An adjustable pump can do wonders for a NFT system because dialing in the flow of nutrient solution is key to the operation of the system. An NFT system should be designed before purchasing a pump so the specifications are known. More specifically, the pump size for the system will be determined by the distance the water in the reservoir will need to rise in order to reach the first of the series of tubes.
Aeroponics, or fog systems, are hydroponic systems that sporadically spray or mist a plant’s root mass with nutrient solution. Aeroponic systems generally use spray nozzles to create small droplets of nutrient solution. Just about any type of plant can be grown in an aeroponic or fog system. Aeroponics is not as susceptible to warm temperatures because the root mass is not submerged in water.
Tips for Aeroponics
The power of the pump plays a huge role in aeroponic systems. The pump has to be powerful enough to force nutrient solution through all the spray heads. In other words, the number a spray heads and the distances from the reservoir are important factors to consider before purchasing the pump itself.
Also, it is absolutely imperative to use a fully soluble nutrient solution with these systems. Nutrient solutions that are not fully soluble will leave residue and eventually clog the misters or spray heads. The maintenance involved with an aeroponic system includes checking and cleaning spray heads, which must be done on a regular basis.
Deep Water Culture Systems
Deep water culture, or DWC, is a system in which the plant’s root mass is mostly submerged in water and additional oxygen is delivered via an air pump. When water temperatures are kept between 65-70˚F, this system has particularly fast growth, which is unmatched by almost any other hydroponic system. Due to its speed, this system has been a favorite of growers who want to grow monster plants as quickly as possible. Many home growers experiment with DWC because an individual module can be made from a five-gallon bucket and a small aquarium pump.
Tips for DWC
As a nutrient solution gets warmer, it loses its ability to hold dissolved oxygen. This, in turn, leaves a plant’s root mass susceptible to anaerobic pathogens such as root rot. Water temperature fluctuation in DWC systems is unforgivable, especially when temperatures exceed 75˚F.
The best way to combat this is to prevent the water from getting too warm in the first place. Although most hobbyists who are just experimenting with hydroponics will not want to invest in a water chiller right away, any serious DWC cultivator will find a water chiller to be an essential tool for maintaining consistent results.
Aeration is another key factor to DWC systems. Even when the water temperatures are kept in check, it is important to deliver enough air via the air pump. I usually recommend at least three liters of air per minute for every individual plant module.
Undercurrent systems are similar to DWC systems in that the roots are mostly submerged in water and the oxygen is supplied by an air pump. However, in an undercurrent system, a submersible pump continuously moves the nutrient solution between plant modules, creating an undercurrent, hence the name.
The biggest advantage of these systems is the uniformity of the nutrient concentration and the pH in the solution. Also, the constantly circulating water allows undercurrent systems to withstand slightly higher temperatures than a DWC system.
Tips for Undercurrent
The largest consideration for undercurrent systems is the water flow from module to module. If the water flow is inadequate, the system will flood or not work at all. Be sure when purchasing or designing an undercurrent system that the connections between modules are large enough that roots (especially from large plants) will not hinder the flow of the nutrient solution.
Aquaponics is a hybrid of aquaculture and hydroponics. Basically, aquaponics is a system that uses the symbiotic relationship between plants and fish waste. The water in the fish holding tank and the waste produced by the fish are pumped into the hydroponic system and fed to the plants. As the plants use the nutrients in the fish waste, they act as a filter, cleaning the water. The water is then returned to the fish-holding tank.
Tips for Aquaponics
The first thing you must do for an aquaponic system is cycle the system. This refers to the process in which the gardener or the fish add ammonia to the system to get the nitrogen cycle going. Once the cycling process has occurred, the aquaponic system is ready to provide the plants with vital nutrients. In some cases, other nutrients may need to be supplemented to the plants if they are not receiving everything they need from the fish waste.
Hybrid Hydroponic Systems
There are many different types of hydroponic systems with new systems being created every day. Don’t be afraid to experiment. Taking a few aspects from one hydroponic system and combining it with another to create custom hybrid systems is a common practice among indoor horticulturists.
After all, the reason we have any of the currently used hydroponic systems is because at one point a curious grower was not afraid to experiment with his or her ideas. Experimentation is what drives the evolution of hydroponic growing. With a little experimentation, the hobby grower of today could become the leader of tomorrow’s advancements in hydroponic systems.
Hydroponics is a fun and rewarding hobby. Growers who understand how to properly set up and maintain the commonly used hydroponic systems will have less problems and larger returns on their investments.