The urban gardener asked:


“Ebb and flow” hydroponics system is an example of the common arrangement of the indoor garden. Such system is composed of the upper grow bed, which is a box or tray that holds containers with plants. Those individual containers may be filled with various mediums, the most frequently used ones being rockwool, coconut fiber, lava rock, perlite, vermiculite or styrofoam pellets. The best mediums are those that are porous and can accumulate some water for a long time: lava rock is said to be the best in this respect.

The other part of the hydroponic system is the lower bed – the reservoir with the mix of water and nutrients dissolved in it.  Aquarium pump, regularly triggered by a timer, sends water solution up into the tray with plants.

The most important thing is to keep the correct composition of water solution in the reservoir – this is the key factor of the hydroponic garden flourishing. Many beginners find it difficult to maintain the right pH level of the water, necessary amount of nutrients, and their correct ratio. 

Standard organic plant nutrients are available to fertilize plants; however, many people are reluctant to do that, as they think such fertilizers will quickly make the water reservoir dirty. Indeed, organic nutrients interact with the organisms in water, which leads to their decomposition. Specialized concentrated nutrients, on the other hand, keep the reservoir relatively clean, since they are synthetically made and thus they cannot interact with the organisms in water. Nonetheless, such “clean” fertilizers will severely burn the plants roots if used in access.

Being pumped into the grow bed, water with a fertilizer saturates the plants and returns to the reservoir lacking the previous amount of nutrients and ppm (parts per million). Thus, its composition is always different and changeable. That is why a gardener should always monitor water solution, controlling its pH level and plant nutrients amount.

The urban gardener asked:


Carbon Dioxide (CO2) Systems

Carbon Dioxide (CO2) as described in the previous paragraphs is one of the most important elements needed for plant growth. CO2 is combined with nutrients, water and energy from light (grow lights/ sunlight) is utilized during photosynthesis producing essential sugars that provide energy for the plant. Any factor missing needed for photosynthesis will limit the plants growth potential. In order for a plant to grow to its utmost potential and for it to yield the best results all of the elements must be present. 

Carbon Dioxide (CO2) Injectors

One of the most cost effective way of adding CO2 to an indoor hydroponic garden system is with the use of CO2 injectors. A valve, regulator and gauge are used to measure CO2 levels injected to the air. Sophisticated CO2 injectors are also used to control CO2 release. CO2 tanks are readily available from medical supply outlets and restaurant supply stores.

Carbon Dioxide (CO2) Generators

Investing in CO2 generators would also be wise for long time use in your indoor hydroponic garden systems for several crops. CO2 generators burn propane, natural gas or other carbon based fuels to produce carbon dioxide. More expensive than CO2 tanks, they provide a more convenient way of producing CO2. Long period and continuous use of CO2 generators has proven to be more efficient and economical than purchasing injectors and many tanks.

Carbon Dioxide (CO2) Monitors and Controllers

CO2 monitors with controllers automatically maintain indoor hydroponic garden systems CO2 levels. It is advised for large-scale gardeners or hobbyists and enthusiasts with that extra cash to invest. Often in the hundreds of dollars, they are quite expensive but are really effective if you can afford it. An electronic CO2 monitor together with a CO2 controller are used to maintain CO2 levels. Monitors could be sold separately and can be used with various types of controllers giving room for flexible indoor hydroponic garden designs. 

Water

Water quantity requirements vary according to the type of indoor hydroponic garden system. Adequate levels of water should be maintained whatever type of indoor hydroponic garden system used. Water deficiency even if reversed and corrected cause permanent loss in production.

Not only the amount of water but also quality of water is important. Poor quality also causes serious problems for any indoor hydroponic garden system. The use of tap water can affect the nutrient balance in hydroponic nutrients solutions. Tap water naturally contains mineral and salts. Often referred to as “hard water,” tap water is offset by constant monitoring and adjusting nutrient solution. Salt content should always be kept below 325 ppm (parts per million) whenever possible.

Temperature

 

Temperature is a gauge for optimum production for every plant. When plants are exposed to extreme ranges of temperature, stunted growth and poor fruit yields are the result. Plants have specific temperature ranges for their ideal growth. Warm-season vegetables and most types of flowers have 18o C and 260 C as an ideal temperature range. Cooler season vegetables like lettuces have a 10o C to 18o C range.

The urban gardener asked:


These are the materials that mimic the soil in everyday gardens. It serves as a support system for your hydroponic indoor garden. They function mainly for anchoring the roots and a reservoir for water and nutrient solutions. Special attention is also placed on aeration or proper plant respiration and drainage. A balance must be kept between keeping the plant nourished and over saturating the roots.

 Types of Growing Mediums

 Choice of a specific growing medium mainly depends on the type of growing system to be used. Certain systems have no mediums used because plant growth is best when roots are suspended in air or water. Improvement made with newer growing medium mixtures has been introduced for optimum plant growth in certain systems. Ideally, an equal mixture of water and air is advised making it available for the roots to utilize at all times. Water by gravity always moves downward through coarse mediums only to be deposited in the bottom of the container. This is eliminated with the use of a hydroponic system as water is constantly circulated in the system. The only system that this would not work would be the Ebb and Flow Systems.

 Clay Pebbles

Recyclables, it can be constantly reused indefinitely reducing upkeep costs for your indoor garden. Size of the pot is one limiting factor as they do not possess good nutrient lifting ability, but effectiveness is enhanced in smaller pots and containers. Another advantage would be their neutral pH and they don’t retain nutrients. Ventilation and aeration are also maximized because of the spaces created between pebbles.

 

Clay pebbles are usually used together with net pots in drain and flood indoor hydroponic gardening systems. Water flow in roots is enhanced by their natural shapes and spaces hey create between them, therefore maximizing the absorption of nutrients. When using the Drip irrigation hydroponic system, use absorbent mediums to provide better retention and nutrient circulation.

 Coconut Fiber

Shredded husks of coconuts as a growing medium has also been growing in popularity. Packaged in a variety of ways like blocks, pellets, cubes and shredded fiber it can be a good substitute for any type of growing medium. It is also commonly mixed with other growing media such as perlite or rockwool.

 Why Use Coconut Fiber as a Growing Medium?

 Coconut fiber is actually a waste product; its ability to be used for other useful means takes a great step towards recycling and environmental awareness. It is the first totally organic medium which could be utilized for indoor hydroponic gardening. It is superior to rockwool in water handling ability and oxygen capacity. Coconut fibers also possess root stimulating hormones and prevent root disease and fungus infection. In its natural state, coconut fibers provide a good and rich medium for the coconut when it lands in the ground.      

Special attention should be given as to the quality of the coconut fiber to be purchased. Low grade quality is not well suited for gardening as they contain high sea salt content and fine grain texture. 

Perlite

Originally used as an additive to aide aeration and improve soil drainage, it has become one of the popular hydroponic growing mediums. Commonly used with a 50/50 mix with vermiculite, it is derived from volcanic glass with holes throughout produced by exposing it to high temperatures created by water bubbles.

 Advantages of Growing with Perlite

 Inexpensive and readily available is one of the causes of its popularity. Used in wick type hydroponic systems because of its aerate nature thereby giving a good wicking action.

 Disadvantages of Growing with Perlite

 Health hazards come with the use of perlite when inhaled, a mask is suggested when working with perlite as a growing medium. A high degree of care and maintenance is also required. Water retention is one of its weakness therefore constant watering is required.

 Vermiculite

Used in conjunction with another growing medium compliments the qualities of the other. A popular and common mix is that with perlite. In a 50/50 mix vermiculites property which is water retention (200 – 300% of its weight in water) complements perlites very porous quality and a balance is achieved.

 Dangers of Using Vermiculite

 Vermiculite can be a health hazard if not handled properly. Due to its nature of containing small amounts of asbestos, it can be very dangerous when inhaled. It easily dries on an individuals fingers when touched even when wet. It is not also practical to reuse because of the rinsing and drying required. Water retention is also a problem, because of its high water retention if not used in pair with another growing medium, root damage is likely and plant death are the result.

 Rockwool

Rockwool specifically made for indoor hydroponic gardening systems. It has remained as one of the popular growing mediums. Transplanting plants when grow too big from their previous containers is also eliminated. When this happens the existing cube with the plant is merely placed on top of a larger cube and the roots would grow through both cubes. Water retention qualities of rockwool is 10 times greater that of water. Its porous nature makes it virtually impossible to over water. Recyclable, it can be used for the next crop by merely rinsing, making it economical and environment friendly.

 Disadvantages of rockwool

 A natural pH found in rockwool is one of its disadvantages, pre-treatment is required before it is used as a growing medium. Methods of lowering its alkaline content includes mixing it with a solution of pH down, trace mineral solutions and a 24 hour fish emulsion and is then rinsed thoroughly. Gloves should be used when handling rockwool because of skin irritation but is not when rockwool is wet.

The urban gardener asked:


A great indoor garden requires a good grow light. It could mean the difference between success and failure. Having the right hydroponic light is the single-most important and costly decision in setting up your garden.

 Hydroponic grow lights come in three main types:

 

Incandescent lights

These are the usual lights found in homes. They are generally a poor choice for garden grown lights because of their limited light spectrum and inefficiency.

HID (High Intensity Discharge) grow lights

Producing more light (up to 10x more lumens/watt than an incandescent light),are more efficient. Drawbacks would be, they produce more heat, generally more expensive than incandescent lights and requires the additional expense and maintenance with ballast. It takes around 100 hours before hydroponic HID grow lights reach their optimum working conditions, or until they reach light intensity and color stability. 

Natural Sunlight

Expense for acquiring artificial lights can be skipped by using sunlight. This is done with the use of solar room, greenhouse or large windows which allows plenty of sunlight. Or you can do this outdoors; hydroponics does not necessarily mean the cultivation of plants indoors but it growing plants without the use of soil.

Basic setup for an indoor garden is 1000w of lighting for and area of 16-25 square feet of plant area. Reflectors and/or light movers should also be considered as they improve efficiency of the indoor hydroponic gardening system. Ballast may also be needed as numerous hydroponic grow lighting require igniting.

 Some Basic Facts

Before plugging in your grow light

Different plants require different levels or types of lighting, this paragraph would deal on some simple know-how on how to make an effective lighting setup. In setting up your garden, it is essential that you determine your growing area in order to determine the best lighting setup for you. Light is an essential factor in the growth of plants, it is important that the lighting solution you chose for your garden is adequate for its size. A poor or ill advised decision would certainly reflect on the quality of plants you produced. Inappropriate budgeting like cost cutting specially on lighting would just prove to be uneconomical and inefficient in the long run.

A general rule for lighting that area coverage is determined by a light wattage output. Reflectors might be used to increase the light area and reach corners but effectiveness is still determined by this formula.

Day and Night Cycles

The type of plant and its stage of growth generally determine the amount of light needed. A common cycle is that with 18 hours of light and 6 hours of darkness which is recommended for its vegetative growth phase.

For seedlings, a continuous light source is needed until the first real leaves appear. When the leaves appear, the regular 18/6 light cycle is used. Fluorescent or incandescent lights are best for seedling because of the low heat and soft light they generate. Automated timers maybe used to ensure consistent light cycles. Inexpensive timers are also available; this can be found any hardware or Home Depot/ Lowe’s type store.

Light and Photosynthesis

The plants exposure to light intensity, duration and light color directly affects the amount of energy needed for photosynthesis. The color of the light, Blue simulates the summer sun, Orange for autumn seem to stimulate photosynthesis best. The light spectrum produced by metal halide bulbs (Blue lights) and high pressure sodium bulbs (red/ orange lights) produce this effects. HID grow lights produce these effects owing to their popularity to hobbyist and professionals. Combination of metal halide and high pressure sodium bulbs provides the complete spectrum of light produced by the sun.

Use Caution When Working with Lights

The combination of water, electricity and chemicals in such a closed-in space makes the grow room one of the most dangerous places in your house. Keep in mind to separate your ballast by elevating it from the water-containing areas of your hydroponic growing system.