- Solution culture grows vegetation without any growing medium, such that plants' roots are fed directly by a liquid-nutrient solution. The plant may sit directly in a large bucket of nutrient-rich water, for example. Aeroponics is a subset of solution culture, in which plants grow while suspended in a chamber of air. Misters spray roots with water and nutrients at regular intervals.
Medium culture also feeds plants by means of a liquid-nutrient solution, but additionally uses an inert physical medium (such as gravel, perlite, mineral wool, expanded clay, sand or coir) to hold the roots in place. The "ebb-and-flow" method is a popular form of medium culture. In this system, plant roots are saturated and subsequently drained of nutrients and fluids at regular intervals.
- Hydroponic techniques can be used in areas of the world where there is insufficient or infertile soil.
- Hydroponic systems can be used all year 'round. Plants may be grown out of season and outside of the region they naturally grow in.
- Hydroponic systems use significantly less water than conventional ones, especially when water is recycled and recirculated through the system. This results in a lower water bill.
- Many growers report increased yields using hydroponic techniques.
- All environmental growing factors may be precisely controlled in a hydroponic system.
- When grown hydroponically, plants are sheltered from outdoor pollutants.
- Using non-soil growing systems reduces the need for many hazardous pesticides that tend to accumulate and remain in the soil.
- Nutrients may be recycled throughout the system.
Disadvantages of Hydroponic Systems
- Complete hydroponic systems require a high initial financial investment.
- Systems must be continually monitored and maintained, and refilling supplies may become prohibitively expensive long-term.
- Retailers of manufactured hydroponic systems may inflate claims about their products.
- Vegetation growth may be stunted because of insufficient light or carbon dioxide levels.
- Intense artificial lighting sources may cause a significant increase in electricity consumption and power bills.
- Maintaining a properly functioning hydroponic system requires substantial time, dedication and know-how. There are many precise factors that must be accounted for, and inexperienced users may be likely to fail in producing healthy crops.
- Ebb-and-flow systems are prone to a buildup of salts that inhibit the ability of the plants to take in nutrients.
- Hydroponic systems are susceptible to harmful bacteria, mold growth and odor.
- There is no guarantee that hydroponically grown produce is as healthy as their conventionally grown counterparts.
Hazards of Hydroponic Systems
- Hydroponic systems can pose a serious fire hazard, especially when grow lights are used improperly, electrical connections are frayed, ventilation is lacking, or flammable materials are in the vicinity.
- Damaged metal halide lights may cause serious skin damage.
- Hydroponic systems are prone to electrical hazards, especially when there is exposed wiring that could come into contact with water.
- High-intensity discharge (HID) lights pose a risk of explosion, especially when exposed to water.
- High levels of CO2 from CO2 generators can be toxic to vegetation and to people. Improperly burned fuel in carbon-dioxide generators can produce carbon monoxide.
- Tangled electrical cords, or extension cords strung on the floor, may pose a tripping hazard.
Inspection of Hydroponic Systems
- A certified electrician should supervise all electrical wiring work.
- All electrical cords should be neatly organized and connections should be in good working order, with no exposed wiring.
- Grow lights should be shut off for at least six hours each day.
- Growing containers should be free of leaks.
- Growing areas should be cleaned frequently and always kept free of pests.
- Humidity levels should be closely monitored and controlled so as to avoid a buildup of potentially problematic moisture.
- Flammable items should be placed far from the hydroponic system, as such items pose a fire hazard when grow lights are powered on.
- HID lights should have ample clearance so that they are allowed to properly cool when turned off.
- HID bulbs should be kept free of fingerprints and moisture, and should not be turned on when they are cold.
- Metal halide lights should have protective coverings that minimize hazardous UVB rays from leaking out.
- Ballasts and HID lights should be placed in a position where they cannot be accidentally knocked over.
- The growing area should be well-ventilated with oscillating fans.
- Electrical circuits and receptacles should never be overloaded.
- Electrical cords should be properly matched to the receptacle; grounding wires should not be cut off of cords to use in non-grounding receptacles.