The urban gardener asked:

Grow Light Reflectors

Often neglected as to their importance, grow light reflectors play a major role in a good indoor hydroponic garden system. Light plays a great role or the most important role in photosynthesis. The use of grow light reflectors in your garden enhances light distribution and ensures uniform distribution. Discounts on quality grow light reflectors are easily available and a super cost effective way of improving your personal garden productivity and efficiency. With effective planning, the use of the right lighting system together with grow light reflectors greatly expands your garden area.

Size and shape are important factors when considering the right grow light reflector. Grow lights and their configuration and personal preference for the amount of light needed to grow your plants are taken into consideration. Horizontal placement of the lights and reflectors are effective ways of mounting this system. Garden size also determines what shape and size of grow light reflector to be used. Smaller grow light reflectors produce higher intensity light beams because of their shorter travel distance.

Air-Cooled Reflectors

For additional ventilation and heat control, air-cooled reflectors are used. Indispensable for those gardens cramped in small spaces because of the amount of heat generated by grow lights. It maybe difficult or close to impossible to maintain proper ventilation in such enclosed garden by the use of external fans. Usual setup for indoor hydroponic gardens includes grow lights with air-cooled reflective hoods covered by glass heat shields. This allows the light source to be placed closer to the plant canopy ensuring better light ***********. Gardens with no special cooling requirements also gains to benefit from its installation. This is the ideal setup of an indoor hydroponic garden system; investing a little more provides maximum garden performance and enjoyment for gardeners and hobbyists.

The urban gardener asked:

hydroponic plants receive all the nutrients they need for growing and fruiting from the growing liquid with all the nutrients dissolved in it. Hydroponic nutrients are available in great variety at specialized hydroponic stores. By the way, both chemical nutrients and organic nutrients can be used for the needs of hydroponic gardening. The only thing to remember is that organic fertilizers require more skills, time, and attention to use them effectively.

Hydroponic gardening allows anyone to grow organic vegetables, fruits, and flowers. A little research, learning and training, combined with enthusiasm, will soon bring the first success in hydroponics to you.

Today, there are many ready-made hydroponic systems available on the market. They are not too expensive, but such systems can really help to make an easy start in hydroponic gardening. For the beginning gardeners it is even recommended to choose simple inexpensive hydroponic systems – they are enough to give you the necessary experience. Of course, you can always build you own system to suit all your particular growing conditions and requirements, when you have enough experience and understanding of how hydroponic system works.

If organized properly, hydroponics gardening can even be easier than traditional plants growing. For example, with hydroponic system it is much easier and less time-consuming to test and maintain the necessary pH level in comparison to the regular soil gardening, where even the pH level testing can be a very challenging task, not speaking about maintaining it on the required steady level.

After all, it is necessary to remember, that in spite of the fact that hydroponics differs significantly from traditional gardening, it is nothing but an alternative approach to grow the same fresh, tasty, and healthy food. Just spend some time to research the topic, evaluate all the benefits of hydroponic gardening – and you will see that there are many advantages offered by hydroponics. Growing healthy organic vegetables without polluting and exhausting fertile soils is definitely one of them.

The urban gardener asked:

Hydroponics vs Soil Grown Plants

The benefits, offered by hydroponics, are pretty simple, yet impressive: one can receive 200-1000% increase in yield with only half of time and space requirements in comparison to traditional soil horticulture. Absence of soil also results in protection of growing plants against pests, commonly living in soil. In hydroponic systems, plants receive all the necessary nutrients through hydroponics nutrient solution and never suffer lack of water. As the result, hydroponic plants concentrate of producing fruits instead of growing large roots to extract water and nutrients from the soil. Hydroponic plants have smaller roots in comparison to common plants, which grow in soil. This allows increasing the density of plants in your garden. It is also a proven fact, that food products, produced in indoor hydroponic systems, are cleaner and have longer shelf life.

Usually, hydroponic plants can grow both indoor and outdoor; furthermore, even a loft, cellar, or closet can be turned into a garden with hydroponic system.

There are two major subtypes of hydroponic plants: solution and medium cultures. Solution culture does not require any growing medium for its growing; the only thing necessary is nutrient solution. Among solution cultures aeroponics, static and continuous flow cultures are defined. Medium culture needs a particular growing medium to grow in, for example, rockwool, sand or gravel. In most cases, the growing medium is contained within a reservoir, made from plastic. However, glass, metal or wooden containers are also used. The only requirement to hydroponic container is that it should not let light pass.

History of Hydroponics

Hydroponics as a term was first mentioned in the middle of the previous century to identify a method of plants growing without soil in the special growing medium. However, the method itself has roots in the prehistoric times. The Floating Gardens of Aztecs and those of the Chinese, Hanging Gardens of Babylon, perceived much as the myth only, and the flooding of the Egyptian Nile may now be treated as the very first attempts of hydroponic gardening. Moreover, even ancient Egyptian hieroglyphic records, which are actually documents, not myths, mention the ways of growing plants in water.

Thus, it would be unfair to say hydroponics is a brand new method of gardening: even Da Vinci made much progress in creating what we now call “hydroponic gardening”. At the same time, research of the last decades has significantly explained and improved the nuts and bolts of this agricultural option, actually, reviving it. This process started during World War II thanks to the government financing, and in the 50th of the 20th century it gained worldwide popularity. Just for the record: these days the incidence of hydroponically grown fruits and vegetables occupy about 65% of all those sold in the UK stores, and about 90% of the sold cut fresh flowers are grown with the help of hydroponics and HPS grow lights.

Among the researchers who worked on creating the ideal conditions for plants growing was a Belgian scientist Jan van Helmont, who discovered in 1600 that plants receive elements for the normal growth from water. Robert Boyle from Ireland managed to grow plants in the bottles with water, which is recorded in the documents dated 1666. 33 years later a notable discovery was made by the English scholar John Woodward, who found out that various constituents from different types of soils were also of vital importance for the plants growth. Thus, he made a valuable contribution to the work started by Jan van Helmont. Unfortunately, the absence of the necessary equipment prevented John Woodward from proceeding with his work.

With the development of chemistry the world got to know that plants consist of chemicals obtained from air, soil, and water as food and the materials for the proper growth. This real breakthrough was made by the French scientist Nicolas de Saussure in 1804. Jean Boussingault, his fellow countryman, made much progress in studying plants growth in various types of medium, as quartz, charcoal, and sand. That was he who found out that dry plant material is mainly made of hydrogen and carbon dioxide, received from the air.

Knowing the plants’ chemical structure and the ingredients necessary for the growth scientists became curious whether it was possible to grow plants without soil.

The scientists who succeeded in this task were Germans Sachs and Knop, who managed to grow plants in water solution in 1860’s. They called their invention “nutriculture”. Many years passed till the real interest to the “nutriculture” appeared. The pioneers of the greenhouse industry fully understood its cons and helped in the further improvement of the method between years 1925 and 1935.

The first effort to turn laboratory “nutriculture” into a commercial product was first made by Dr. William F. Gericke, who explored soilless plant growing at University of California Davis and was very successful. It was Dr. Gericke, who first used the term “hydroponics”, which means “waterworking” in Greek. Since then, the public interest to hydroponic gardening spread rapidly around the world.  It is interesting to note that even the U.S. Army had special units, whose main duty was to grow hydroponics and provide fruits and vegetables for kitchen. In the military environment it is not always possible to grow plants in a traditional way, so hydroponic systems and hydroponic supplies was chosen as the way to grow plants virtually anywhere.

The urban gardener asked:


The most widely-spread growing medium is, perhaps, rockwool. Originally used for insulation purposes and also known as mineral insulation, rockwool was first used as growing medium by Dane gardeners. Now, it is frequently used for drip-style indoor gardens around the globe.

Rockwool is produced by a process similar to making cotton candy: a particular mixture of sand and rock is melted and then turned into fibers by spinning the mixture to form products of multiple shapes and dimensions, from 1″ starter cubes and up to large slabs of  3″x12″x36″ in size. The variety of available forms and sizes turns rockwool into one of the most widely-used growing mediums.

Key advantages, as well as disadvantages, of this popular growing medium are listed below.

Rockwool’s Strong Points

HOLDING WATeR – rockwool as a growing medium in hydroponics systems is capable of holding a large amount of water. This creates an additional protection for situations, when water is not supplied because of power outages or failures in pumping or other gardening equipment.

ACCUMULATING AIR – up to 18 % of air are constantly kept by rockwool. Due to this capability, there is a very little risk to over water rockwool; besides, the plants are always supplied with enough amount of oxygen.

MULTIPLE SHAPES AND SIZES AVAILABLE – whether it is a small 1″ cube for seeds propagation or a large 3x12x36 inches slab for huge plant, rockwool offers a wide variety of shapes and sizes to choose from. Besides, loose rockwool is also available, designed for filling different plant containers.

NO DUST AND EASY TO USE – since rockwool maintains its form almost perfectly, it cannot be scattered accidentally. Besides, usually packed into plastic rockwool is a very clean material that is easy and comfortable to work with.

Rockwool’s Weak Points

NOT A “GREEN” MATERIAL – rockwool is claimed to be not environment-friendly material, because of its almost indefinite time of breakdown.

HEALTH HAZARDS – rockwool particles and fibers pose serious health danger, especially for human lungs. That is why it is necessary to wear a protective dust mask, while working with rockwoll.

pH PROBLEMS – because of rockwool’s high pH level, it is necessary to balance pH level in the nutrient solution properly and make it suitable for the plants, you are growing. In general, the use of rockwool requires more routine work to keep pH level of your nutrient solution at steady level.

LONG PRE-SOAK PERIOD – before rockwool can be used in the hydroponic system, it should be soaked for at least 24 hours beforehand. Other growing media usually do not require pre-soaking, it is enough just to well-water them.

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:


 

Along with water, hydroponics plant nutrients, CO2 and oxygen, grow lights is the key basic component, required by plants to live. Providing additional light is necessary for indoor gardening. Furthermore, light should resemble the sunlight as much as possible. The major concern with other types of lights is that they do not produce light in the appropriate spectrum, required by plants.

Being the most efficient bulbs, HPS bulbs are commonly used by gardeners. Producing light in red and yellow spectrum, light generated by high pressure sodium lamps resembles the natural sunlight during autumn. Due to this peculiarity, HPS light is the best for promoting plants blooming. However, some plants may react negatively to this type of light, growing with oblong stem, etc. To address that issue, new HPS bulbs with color correction have been developed. For example, Son Argo feature properly balanced light spectrum, which suits perfectly for the needs of indoor gardening.

High pressure sodium grow lamps are made of a semi-transparent ceramic arc tube, filled with a mixture of sodium, mercury, and xenon. The arc tube is placed into the protective outer glass shield, similarly to metal halide bulbs. The power ranges of HPS bulbs vary from 35w to 1000w, while the most popular are 250w, 400w, 600w and 1000w.

HPS bulbs are more durable in comparison with MH bulbs: they can be replaced once every 24 months. Though HPS grow lights lose their brightness slowly, in order to keep the brightness at the steady level, it is still recommended to replace the bulb within the specified period.

Among the brand new types of grow lights are sulfur lights, which are said to feature extremely high brightness and effectiveness. However, these bulbs are still rare on the market in view of the high price, so it is early to evaluate their practical value for those gardeners, for whom indoor hydroponics growing remains a hobby.

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:


Soil less Mixtures

There is a great amount of soil less mixtures available, which contain different ingredients. Sphagnum moss, perlite, and vermiculite are the most widely spread hydroponics components, used in such mixtures.

Being organic, soil less growing media are usually used for container gardening wick systems or on-recovery drip systems. It is also possible to use soil less mixtures in recovery systems, however, it is necessary to remember that because of very fine particles in such mixtures, they can clog tubes, pumps and drip emitters, when used without a good filtration system. By the way, according to the urban gardeners, one can use panty hose as a filter: just fit it to the return line and to the pump inlet, and all the tiny particles will be filtered out.

Most soil less mixes form a good growing medium for multiple hydroponic and organic gardens, because they can hold water well, have great wicking action, and, at the same time, they provide a reasonable amount of air to the roots of growing plants.

 

Coconut Fiber

The popularity of coconut fiber as growing medium increases rapidly around the world. Being the first totally organic growing medium, providing highest performance for hydroponic systems, coconut fiber may soon become the most popular growing medium ever. It is interesting to note that coconut fiber is, actually, a waste product, which contains the powdered husks of coconuts.

In comparison to rockwool, coconut fiber is characterized with higher oxygen capacity and water retaining. These features are important advantages for hydroponic systems with intermittent watering cycles.

Coconut fiber also contains a lot of root stimulating hormones, thus offering some protection against fungus infestation and other root diseases. The mixture of 50% coconut fiber and 50% expanded clay pellets is considered to be the perfect growing medium.

However, it is necessary to underline one precaution when buying coconut fiber. Avoid purchasing a low grade coconut fiber, which is very fine grained and contains a high level of sea-salts. Such coconut fiber will have negative and disappointing effect on hydroponic system.

The urban gardener asked:


Complete freedom from environmental factors gives indoor hydroponic gardening its ultimate advantage. All the elements needed for optimum plant growth are provided by the indoor hydroponic gardening system. Light, temperature, pH, CO2 and Oxygen are important factors that should be considered in planning your indoor hydroponic garden system.

 Light and Photosynthesis

 Essential sugars are created by plants through photosynthesis which is the process of converting carbon dioxide, water and nutrients into energy. Light is considered the most important factor because it provides energy for this chemical reaction. Studies show that an increase in light intensity directly increases the amount of sugar produced. This steadily goes up till the saturation point for light is reached by the plant. Increasing the level of light received by the plant should also be considered. Normally, a plant receives around 8-12 hours of sunlight in a day depending on the season. Plant exposure to this amount of light received in a day should be maintained in an indoor hydroponic garden system. Spacing is also important, be sure that they don’t block the light and ensure all plants received equal amount of light.

Plants not receiving enough grow light will have lasting negative effects on its growth even when corrected. Some characteristics are stems which are spindly and elongated leaving them ineffective in supporting plant growth. A decrease in the amount and size of the leaves is also one problem. More damaging effects of improper lighting are a decrease or absence of fruits, decreased overall quality and a change into a yellowish pigmentation for the plant.

Carbon Dioxide also plays a major role in Photosynthesis. Plants utilize the CO2 present in the atmosphere than anything else. CO2 systems are available which increase the levels of CO2 in your indoor hydroponic garden system

Good ventilation should also be considered as they maintain temperature and a steady fresh supply of CO2 and oxygen at all times. Complex setups require more complicated ventilation systems but an oscillating fan set on the same timer as the lights would ensure airflow that eventually allows for optimal plant nutrients in an hydroponic system.

The urban gardener asked:


Hydroponics implies growing of the plants without soil; however, they still need medium to grow in. Hydroponics stores online or local ones offer a wide range of mediums to choose from, and it is better to know them to make the optimal choice.

Different Types of Growing Mediums

Although almost any substances can more or less serve as the growing medium, the most popular are those named below:

- Water / Air / Sand / Gravel

- Vermiculite / Perlite

 - Lava Rock

 - Sphagum Moss / Sawdust

 - Expanded clay pellets

 - Oasis Cubes

 - Coconut Fiber

 - Fiberglass Insulation

 - Proprietary Soilless Mix

 - Rockwool

Although rockwool is the last in the list, it can definitely be named the most popular growing medium among hydroponics gardeners, because it is easy and cozy to use.

Rockwool was initially used as insulation material in building. However, hydroponic gardeners in Denmark were the first to discover its advantages when used as a growing medium. Nowadays, rockwool is highly valued and commercially available in the forms of rockwool cubes and rockwool plugs. To produce rockwool stone and sand are melted together and then spun into various shapes and sizes, which sounds similar to the production of cotton candy.

Rockwool Advantages

Rockwool cubes (sized 36” by 12” by 3”) are very convenient to use, because they can be easily cut to a shape matching your needs. This material perfectly holds water and air, being very porous. Therefore, the roots of the plants will be protected both from rotting and drying out in case of the pump malfunction or other event long enough for you to be able to correct the situation.

 

The granules of the rockwool plugs keep together well and are not less easy to use.

Precautions

Unfortunately, rockwool has weakpoints as well, besides the benefits mentioned above. It can hardly be called environmentally friendly, as it is made of rock and thus does not bio-degrade, requiring some efforts to eliminate it. Moreover, it can be dangerous for the human health, causing silicosis if accidentally inhaled. For this reason, it is recommended to wear a face mask with a HEPA filter and handle rockwool carefully. 

One more thing, a gardener should keep in mind while using rockwool, is that this material has a very high pH level, which should be reduced with available acidic substances and regularly checked.

In spite of the rockwool cons, it is still so easy and comfortable to use that it remains the most popular growing medium type among the hydroponics gardeners. The only thing to do is to take necessary precautions while working with it.