In conventional cultivation plants are grown outdoors. Though plats get all the growth inputs outdoors, they are also exposed to pests, parasites and the vagaries of the elements. That is the way Mother Nature intended it to be. But man had different ideas. He learned to grow plants under simulated conditions in indoor grow rooms. He learned that under simulated conditions in indoor grow rooms plants can grow faster and healthier provided they receive what are known as Growth Influencing Factors (GIFs), in the right amounts. The GIFs include sunshine, wind, rain, temperature variations, carbon dioxide, oxygen, pH, nutrition. Growing plants with hydroponics is basically about controlling the environment in the grow room for the GIFs to stimulate plant growth.



Light: Lights come in various types and sizes ranging from 175 watts to 1000 watts. A 1000 watt light can illuminate and area of 16 to 25 sq. ft depending on the desired light intensity. Though lights can be used by themselves, it makes more sense to use lights with reflectors. Reflectors allow more efficient use of the light given off by the lamp. The light produced by different lamp types is usually diffuse, that is it is scattered in all directions. Reflectors direct the light in the desired direction thus enabling more efficient utilization of the lamp output.

How much light a plant will need depends on several factors including the stage of the plant life cycle. Though the requirements vary from plant to plant, generally seedlings need continuous exposure to light while stem cuttings do well with 18 hours of light. At maturity plants require 18 hours of light followed by a 6 hour period of complete darkness.

Timers can be used to automate the switching on/off process to suit the plant needs. Timers help to establish day/night cycles in the grow room independent of the day/night schedules outdoors. Timers also help to schedule the cycles to suit your convenience. Additionally, light movers can be used to more evenly distribute the light output to allow greater uniformity of exposure to the plants. Light movers move the lights along a circular or linear track and thus ensure that all plants in the grow room get adequate exposure to light.

Nutrition: Nutrition ranks second in the order of importance of the growth influencing factors. In hydroponics cultivation plants get their nutrition from the nutrients that are fed to them in solution with water. Depending on the type of hydroponics system the solution is available for nutrient uptake continually. In the hand watering system the nutrient solution is fed at regular intervals, while flood and drain systems achieve the same effect by regularly flooding and draining the solution around the root area. The constant supply of food results in enhanced growth.

Electrical conductivity (EC) is a measure of the amounts of total dissolved solutes in the solution. It is measured in milliMhos and its optimum value varies for different plant varieties. As EC does not identify the amounts of specific nutrients present, it is best to use pre-mixed 2-part hydroponics nutrient formulations, as it is easier to achieve the ideal EC with them rather than attempting different formulations with individual components.

pH: pH is a measure of the acidity of alkalinity of the nutrient solution. pH is important as plants can absorb the nutrients only if the pH of the solution is between 5.5 to 6.5. If pH is out of this range plants cannot absorb the nutrients efficiently and growth will suffer. pH measurements need to be taken on a daily basis. Even small variations in pH may have an adverse impact on plant growth. The pH can be easily adjusted using pH Up or pH Down solutions to obtain the desired level.

Carbon dioxide: Plants manufacture sugars from two simple raw materials ?carbon dioxide and water. The process of manufacture is called photosynthesis and requires the presence of chlorophyll and sunlight. Carbon dioxide is vital to plant survival. In the atmosphere carbon dioxide is present to the extent of 340 parts per million (ppm). According to research plants can use more carbon dioxide to the extent of 1500 parts per million (ppm). Carbon dioxide enhancement stimulates enhanced plant growth. Carbon dioxide enrichment of the grow room dramatically boosts the yield at marginally extra cost. A carbon dioxide injector installed above the lights allows for maximum intake by plants in the grow room. The injector should be used in conjunction with an exhaust fan to ensure all carbon dioxide is vented between cylces.

Oxygen: It is absolutely essential to provide good ventilation in the grow room which will ensure a constant supply of oxygen. Plants need oxygen for respiration and utilization of the food produced by photosynthesis. With an oscillating fan installed in the grow room ambient leaf temperatures will be reduced which will restore carbon dioxide to the leaf zone and strengthen the stem. This will also ensure good distribution of fresh air throughout the room and control of humidity levels.

Atmospheric temperature: It is important to monitor and control temperature in the grow room in accordance with the plant's perceived day and night cycles. When the light is ON the plant perceives it as daytime; daytime temperature of the air should be controlled around 18 to 25 deg. C. ?Nighttime? temperatures should be regulated between 12 to 18 deg. C. Reliable temperature regulation can be obtained using a thermostat located among the plants.

Hydroponics gardening is not difficult provided you get the basics about the Growth Influencing Factors right. This is important because in the final analysis success in hydroponics depends upon how well you can get the Growth Influencing Factors work for you.