Hydroponics grown outdoors can normally rely upon sunlight during regular growing seasons. For optimum development, containers kept indoors require MH (Meta Halide) lights for sprouting, seedling development and initial growth of hydroponic plants and HPS (High Pressure Sodium) lights for the final flowering and harvest phase.
Meta Halide bulbs provide an intense light of a blue-white spectrum excellent for plant sprouting and growth. High Pressure Sodium bulbs provide an orange shaded light which simulates the autumn harvest time sun. A Meta Halide light can be used for the entire season if only one light is available.
There are special T5 Fluorescent fixtures designed for hydroponics use that contain high efficiency, digital electronic ballasts to power the high out T5 fluorescent bulbs. Do not put standard fluorescent tubes in these fixtures because the high current design may burn out the standard tubes very quickly. These fixtures are ideal for providing a wide light disbursement resulting in a bright and even growing area.
Normal fluorescent or incandescent house bulbs are not recommended. Fluorescent lights provide a gentle light but do not provide the intensity of light required for most plants. Incandescent bulbs (normal light bulbs) are expensive to operate, create as much heat as light, and do not provide the full spectrum of light required for good plant growth.
A plant's roots need to receive sufficient water to remain hydrated and enable the plant to grow rapidly. However, most land plant roots must not remain waterlogged for too long a period.
Caution: Tap water may contain chemicals that can effect plant growth in some cases. If growth patterns seem abnormally low, you may want to change the water source, use pure rain water or purify water using Reverse Osmosis Systems or similar equipment for serious growers.
In hydroponics, nutrients are fed directly to the plant's roots, not fed to the soil for secondary absorption by the plant through its expanding root system. Therefore, the hydroponics (hydro) gardening grown plant grows and matures faster with less time, effort, space and fertilizer.
The proper mixture of plant nutrients needs to be supplied to the plant roots at regular intervals. The nutrient solution will become weaker over a period of time as the root system selects the needed plant food from the solution. Therefore, it should be completely replaced at regular intervals, usually 2 or 3 weeks apart depending upon the solution and system being used.
In between replacement, it is imperative that the water level be retained at the original level to replace loss due to plant usage or evaporation. Failure to do so may result in over concentration of nutrients and actually 'burning' the plant roots.
A plant's leaves need to have some kind of circulating air to replenish the natural carbon dioxide intake and to reduce the possibility of mold, mildew or plant disease. Carbon Dioxide (CO2) can be added to fully enclosed systems for even faster growth if desired. Plant roots need exposure to oxygen either directly or from freshly aerated water flow.
A plant's roots, just like fish in an aquarium, need to receive a proper supply of oxygen. In garden soil, fresh oxygen containing water is provided to the plants. This water then drains away requiring new water at regular intervals. In a recirculating hydroponics system, the water can be oxygenated by spraying or inserting an air pump (just like an aquariuair pump and air stone outlet) in the water reservoir. Nutrient Film Technique systems are adjusted to provide water to the bottom of the root system and provide space for air flow to the top of the root system.
Carbon Dioxide (CO2)
Plant leaves need a regular supply of carbon dioxide as part of their photosynthesis process. Normally, simple exposure to a location with circulating air is sufficient. A CO2 generator can be added to some fully enclosed containers to provide a richer atmosphere for plant growth. The richer CO2 atmosphere results in speeding up the plants metabolic rate which increases growth rate and yields by up to 40%. No complex equipment is needed.
Simply place the injector in front of an oscillating fan which blows the CO2 over the plants leaves. It should be used with a timer or environmental control devices. It is especially productive in high light intensity gardens.
The plant temperature ranges need to be considered and controlled as much as possible. Simply match as closely as possible the normal temperature range that the plant would face if grown outdoors in a standard garden setting.
Many plants do not need additional support. But some tall plants such as tomatoes may need artificial support systems to enable them to grow normally tall and bear their heavy fruit.
Although the initial cost of setting up a Hydroponics garden seems expensive, the listed equipment is made of high quality material which will last for many seasons.
Five Methods of Hydroponic Gardening
Aeroponics, Drip Method, Ebb and Flow, NFT (Nutrient Film Technique), Aeration Method
The plants are grown in containers or nets which allow the roots to dangle in air above the nutrient solution. An aeroponics mister pump forces a spray of nutrients through the roots at very frequent intervals. For example, one minute of spray followed by 4 minutes of drainage. The act of spraying ensures that additional oxygen is mixed with the nutrient solution providing an enriched oxygen, nutrient solution that is very beneficial to the plant and results in rapid growth.
Plants achieve an increase in water and nutrient uptake over conventional soil gardening methods. Soil tends to bind crucial minerals and therefore plants tend to expend a lot of energy pulling the minerals away from the positive ions such as clay in the soil.
This method also eliminates the potential of water logging the root system or exposing the root system to a depleted oxygen supply resulting from constantly recirculating the nutrient solution without using an air pump to replenish the oxygen supply in the water.
The aeroponic cloning systems are also good for starting new cloned plants.
In a Drip system, the nutrient solution is delivered to the plants through drip emitters on a timed system usually scheduled to run for approximately 5-10 minutes of every hour. The timed cycle flushes the growing medium, providing the plants with fresh nutrients, water and oxygen as the emitter is dripping.
The plant roots are most commonly grown in a medium of perlite, grow rocks or rockwool. This system is often used to grow long term crops like tomatoes, cucumbers and peppers.
Ebb and Flow: (also known as flood and drain)
The Ebb and Flow method periodically floods the plant growth medium and roots with water and nutrient solution and then allows the water to drain off exposing the growth medium and roots to air. This procedure can be compared to high tide and low tide at an ocean beach. At high tide the beach sand is flooded with seawater. Then at low tide the water drains back into the ocean exposing the sand to the air. The sand remains moist for a period of time and then becomes flooded again at high tide.
In Hydroponics, the flow pattern of water and nutrient solution must be timed so that the growth medium remains moist during the Ebb period and does not allow the plant roots to dry out before the next flow of water. The growth medium used varies in moisture holding ability which must be taken into consideration when setting the timing cycle.
Most Ebb and Flow systems will flood the grow bed for 10 or 15 minutes of every hour or two. In an Ebb and Flow system, the plant roots are most commonly grown in a medium of perlite, rockwool or expanded clay pebbles. During the Flow period the plant roots and growth medium are flooded with water and nutrient solutions. Then during the Ebb period the roots are exposed to air enabling them to acquire the necessary oxygen. The growth medium retains moisture for a considerable period of time, ensuring that the plant roots do not dry out between the scheduled nutrient solution flows.
Nutrient Film Technique (NFT)
In the Nutrient Film Technique, the plants are normally contained in plastic pots with slitted bottoms that permit the roots to dangle through to the water and nutrient solution in the channel below. The bottom of the root system dangles in the water while the upper part of the roots remain in air at all times ensuring that the roots have access to the necessary oxygen.
The only purpose of using a growth medium would be to hold the plant roots in place or to enable the seed or seedling to sprout.
The Aeration method uses an aquarium air pump to bubble oxygen to the roots of plants immersed in the nutrient solution. Plants are suspended 1 inch above the solution by a 2-inch-deep mesh tray that is set into the container by placing the lip of the tray over the container's edge. A layer of inert material, such as gravel, clay pebbles, or vermiculite, is placed in the tray to provide stability for the plants while allowing the roots to grow down into the nutrient solution.
Standard household light bulbs should not be placed very close to growing plants as they create heat as well as light. The heat generated is unsuitable for hydroponic gardening. The light also doesn't provide the optimum spectrum for starting or growing plants. Recommended for casual house plants only.
Fluorescent Lights provide a better, cooler spectrum for plants but do not provide the full spectrum of grow light for starting or growing plants indoors. They are fine for seedlings and low-light plants but do not deliver the strong light necessary for plants taller than 8 inches.
MH (Meta Halide)
These lights are recommended for propogating and initial growth of hydroponic plants. These bulbs produce primarily the blue-white light end of the spectrum. Their light can be compared to a tropical sun. Blue light drives photosynthesis, translocates sugars and keeps the immune system working properly.
- Sunmaster COOL lamps are rated at 5 or 6 thousand degrees kelvin and will lock plants into a vegetative state.
- Sunmaster NEUTRAL lamps are rated at 4 thousand degrees kelvin for both vegetative and bloom growth.
- Sunmaster WARM lamps are rated at 3 thousand degrees kelvin for superb blooming growth.
These bulbs have enough red light to initiate a hormonal bloom growth and lots of blue light to keep the plants short, compact and healthy during bloom. Therefore you can simply use the appropriate Metal Halide bulb for your current lighting need, growth or bloom.
HPS (High Pressure Sodium)
These lights provide optimum brightness for the final flowering and harvest phase. HPS bulbs elevate the red, orange and yellow electromagnetic wavelengths hitting the plant. This (along with shorter photo-periods) signals the plant to start producing bloom hormones. Plants grown exclusively on HPS light may appear overextended as they search for blue-white light.
Therefore, they are best used as replacements for Meta Halide light when the plants reach the final flowering stage. Caution: The MH and HPS ballasts are different. Do not try to simply replace an MH bulb with a HPS bulb in the same ballast, unless the bulb or ballast is designed for this conversion. Conversion HPS (High Pressure Sodium) Bulbs There are HPS Conversion Bulbs available which are High Pressure Sodium bulbs specifically designed to work in the Meta Halide ballast. These enables you to use both MH and Combination HPS bulbs in a MH ballast thus saving additional wiring and ballast costs needed for the separate HPS lighting.
Conversion MH Bulbs
There are also MH Conversion Bulbs available which are Meta Halide bulbs specifically designed to work in the High Pressure Sodium ballast. This enables you to use both HPS and Combination MH bulbs in a HPS ballast thus saving additional wiring and ballast costs needed for the separate MH lighting.
LED bulb system
The LED (Light Emitting Diode) UFO is the most revolutionary plant lighting product since the inception of High Pressure Sodium lamp. Consuming only 80 watts of power and producing virtually no heat, it boasts light intensity and growth rates exceeding that of a 400W HPS.
The concept of the LED UFO is simple - it uses highly efficient 1 watt LED's, uses only the exact spectrums required for photosynthesis, and uses wide angle directional bulbs. The 1 watt LED is one of the most efficient light sources in the world (lumens per watt). By using only the spectrum required, no light is wasted in the spectrums of light that do little or nothing for a plants growth - such as green light. Lastly the directional LED's ensure 100% of the light is pointed downwards - they do not rely upon reflective materials to direct the light.
The LED UFO is many times over the highest powered LED grow light available. It can be used by itself for all cycles of plant growth (covers 9 square feet), can be combined with fluorescent lighting, or can be used to expand your current indoor garden. It can be used in any application - hydroponics or soil, home or greenhouse!
There are a few Combination ballasts available. These ballasts will accept either MH or HPS bulbs. The manufacturer will clearly state if this is the case.
E-ballasts use a micro processor similar to a personal computer which runs a software program. This microprocessor allows the E-ballast to run both metal halide (MH) or high pressure sodium (HPS) lamps, switch between 50 and 60 hertz, make adjustments for the type of bulb it is running and, will even compensate for degrading lamps by increasing output.
The most efficient way to use high intensity lights is to have them moving within the grow room. Moving the lights will eliminate plants tendency to grow toward the light source and provide light to areas which otherwise may be shaded. Since the light is moving, it can pass quite close to the plants without burning the leaves.
More intensity also allows plants to be placed much closer together, greatly increasing yield and quality.
Moving your grow lights from one end of your garden area and back provides a number of advantages and a few disadvantages:
- The light can be placed closer to the plants without generating plant killing heat
- The light's area of coverage is increased
- Provides a much greater variety of light angles to each plant
- Light will more frequently reach foliage at the bottom of the plant which may have been shielded by higher foliage
- Movement of the light will result in a decrease in the amount of light that each plant will receive
- A timed hesitation at the end of each travel will prevent the middle plants growing faster because they received twice the light overhead as did the end plants
- The timed hesitation will result in a level growing area
- The size and shape of your room will determine the type of light mover that will best suite your needs.
Lineal movers carry the light fixture slowly along a track and back again during the light cycle. Most are six feet long, support a single lamp, and are recommended when the growing area is long and narrow.
Circular movers are best when the length and width of the room are similar. They are designed to carry either one, two, three or four lights, in a 360 degree circle, ideally lighting a ten by ten foot area. This diameter can be reduced but rarely extended.
Light bulb sizing
The optimum bulb size depends upon several calculations:
- Floor space to be covered:
- Plants need between 50 and 80 watts per square foot for optimum growing
- Multiply the length times the width of the growing area times 50 watts/square foot
- Example: a 2 foot by 4 foot = 8 square feet. Multiply 8 times 50 to obtain the number of watts needed. Ex: 400.
- Therefore, you would need at least a 400 watt bulb for this area.
- Metal Halide (MH) and High Pressure Sodium (HPS) bulbs should normally never be less than 12 to 18 inches from the tops of your plants.
- Anything closer than this is likely to "burn" your plant tops from too much heat
- Plants directly beneath a reflector may receive more light than plants on the side of the growing area