Learn about hydroponics

Hydroponics is the method of growing plants without soil. Instead of nutrients in the soil, plants thrive on a nutrient solution which contains the minerals that the plants need. So, rather than searching throughout the soil for minerals, your plants are able to get nutrients easily, directly from the nutrient solution. Grow media -- such as vermiculite, Perlite, coco, rockwool or clay pebbles are often used to support the plants and their root systems and perhaps to hold moisture around the roots. The growing medium is not a source of nutrients in itself.

Hydroponic gardening is an easy, environmentally sound way to grow a wide variety of healthy plants. It offers numerous benefits including:

• Plants grow up to 50% faster than in soil because they have easy access to food and water.
• It is possible to garden indoors all year round
• Nutrients are directly available to plants and don't get bound up
• Little or no pesticides are necessary. Plants start out in a disease-free medium.
• Smaller containers can be used because the roots can grow without being rootbound
• Gardening is possible where it would not be normally e.g. poor soil, rocky areas, even balconies. With the use of artificial lighting it is even possible to successfully garden in a spare room or garage.
• Less labour is required than growing in soil because no digging or weeding is required.
• Since plants do not need to compete for nutrients, more can be grown in a smaller area.
• The increased control over growing conditions makes it easier to provide the best possible environment for plants, leading to better quality produce and higher yields.
• Fast growing healthy plants grown by hydroponic methods are more resistant to pests and diseases.
• You will also notice improved flavour and texture in hydroponically grown fruit and veggies

Artificial grow rooms offer a tremendous opportunity to produce maximum yields of selected plants at any time of the year.  Although the initial set up cost may seem high the bumper crops you'll produce will quickly offset the expense. 

Until recent years indoor crop production was very restricted.  Providing adequate light was the most limiting factor in achieving a viable flowering crop.   Full spectrum fluorescent lights were used effectively for propagation and some limited vegetative growth but proved inadequate for fruiting and flowering.  

Today, thanks to research and advanced technology growing plants indoors using supplemental light has become a popular and economical way to produce a variety of cash crops.  Hydroponics, under lights is the preferred method of cultivation for many growers.  The needs of plants can be met without the use of mineral soil when growing indoors.  Hydroponics provides the necessary mineral elements directly to the plant's roots.  The mineral salts provided in hydroponics are the exact same as those found in soil.  A mineral-based soil that comes from your garden does not work well indoors.  The bacteria that break down the organic compounds into mineral elements that the plants use are quickly depleted.

The easiest way to get started is to create a floor plan.  Measure the designated area and draw your floor plan to scale.  The size of your room in square feet and cubic feet will be important factors in accurately determining the amount of light, C0₂, ventilation etc., required.  The experts at 3 Counties can tell you exactly what you will need for a particular area.  A small closet garden or a full basement set-up can be put together in the most economical way when everything is first laid out on paper.

When deciding where to situate your grow room some of the most important things to consider are:  Accessibility to electricity, plumbing and ventilation.  Determine how many lights, and the wattage you will be using.  Ensure your electrical panel has enough amperage to run the lights and all the equipment.  For example a 1000 watt HID light will require 10 amps.  The average new house has 200 amp service, more than enough to run a small grow room.  When using a digital or segmental timer, a relay or contactor is a must. This is because a timer alone can’t handle the amount of electricity a grow lamp needs to operate. If your timer fuses, your grow lamps will stay on. This can confuse flowering plants.

The walls of your grow room should be covered with a reflective material such as mylar to achieve maximum light reflection.  Do not use tinfoil for reflection as it creates hot spots which may burn your plants. Reflect-a-grow reflective sheeting reflects up to 99% efficiency when it is tacked flat against walls. 

There are several different garden systems used in hydroponics the most popular being ebb and flow, (flood and drain)  deep water culture or pots with soilless mix.  Whichever system you choose the important factors to remember are good drainage, irrigation, and availability of oxygen to the root system.   Easy access to running water and a drain will make the job of filling and empting the reservoirs or hand watering pots much easier.  Keep growing tables elevated to a comfortable working height with enough room to move unrestricted between each table.  A sub-floor is particularly important if growing in pots directly on the floor as the growing medium or root zone should be kept a constant temperature of 75 - 78º F for optimum growth.

It is essential that your grow room be kept clean and free of stagnant water.  Starting off with sterilized equipment and always wearing clean clothes will help keep plants free of contamination.  There are many non-toxic antifungal sterilizing agents available.  If you have been to visit another grow room, nursery or greenhouse it is always wise to shower and change clothes prior to entering your room.  Many insects and diseases are passed through touch or catch a free ride on clothing.  Any new plant material should be quarantined for at least a week before introducing it into your room.  Discard any decaying plant material or used growing medium, reservoir or tables.  Remove any visible algae whenever possible.

The most important growth influencing factor is light. Lights range in size from 250 watt to 1000 watt.  A 1000 watt bulb will cover 16 to 25 square feet depending on the desired light intensity.  It is recommended that lights be used with a reflector to maximize the full use of the bulb's lumen output.  A reflector will make sure all light is directed downward toward your plant and not wasted throughout the room.  The style and size of the reflector you choose will depend on the size of the lamp, desired light intensity and area of coverage. The most efficient way to use any high intensity light is with a light mover.  Lights can be placed closer to the crop, stems will be stronger and plant growth can increase up to 40%. 

Seedlings respond to continuous light.  Place seedlings in a humidity tent under a fluorescent bulb 24 hours a day.  Once the first true leaves appear remove tent and cut light time to 18 hours.  To propagate stem cuttings place them under a  6" humidity dome and provide 18 hours of fluorescent light.  Use a rooting hormone to ensure good root development.

For optimum growth at maturity supply up to 18 hours of light followed by a 6 hour period of  uninterrupted  and complete darkness for respiration to transpire. Respiration must occur in every living cell if life is to be maintained and to allow a plant the ability to use energy and thus grow and produce flowers and fruit.  Respiration occurs mainly during the lights off cycle. Light requirements will vary with growth stages and different plants.

Timers are the easiest way to automate your grow room.  Plants will respond to an accurate day/night schedule and watering routine. With a timer you can establish a day/night schedule that suits your schedule; it is not necessary to conform to the outside environmental dark/light hours. (Plug in fans, pumps and any accessories into the same timer as the light). 

In the summer months the outdoor conditions are reversed, making temperature control infinitely more difficult.    Intake air will likely be as hot and humid as that from the outdoors.  Many times a gardener can escape this by having the lights on in the middle of the night, taking advantage of cooler temperatures.    But the relentless summer heat of the Northern hemisphere will usually catch up with them in the end.   This hot, humid air can have a devastating effect on indoor plants.  This problem can be exacerbated by the increase in temperature from having several lights. Today, many growers switch from their normal HID lighting to to air-cooled reflectors with  separate extractor fans or cooler running CFL lighting in the hottest summer months.

In your growroom it is absolutely essential to have good ventilation with an incoming supply of fresh air (oxygen) as plants will soon consume all the CO₂ in an enclosed environment.  Plants could not complete respiration or utilize the food produced by photosynthesis unless they have a good supply of oxygen. 

 An oscillating fan in the room will simulate the wind reducing ambient leaf temperature, restoring CO₂ to the leaf zone and strengthening the stems.  It will also make sure there is good distribution of fresh air throughout the room which will help control humidity levels.

The extraction fan is one of the most essential and most often ignored pieces of equipment within the growroom. Air movement, through exhaust, can help maintain ideal temperature, humidity and CO₂ levels in the growroom.  There are a number of problems that can easily be prevented by taking control of temperature and humidity ranges indoors.   Air movement has a direct effect on a number of plant processes.  For instance the effect temperature can have on transpiration; a process that is shut down when temperature is excessive or causes condensation when temperatures reach too low a value.

Most indoor gardens are often set up with regard to the winter season, with the air conditions outdoors being drier and cooler than those in the summer. In the winter, for the grower, this is a valuable resource, free of charge.  Well, almost. In fact, all that is needed is a quality extraction fan that is able to remove the volume of air in the room within three to five minutes.  This may have to be accompanied by an additional intake fan, depending on the conditions, the number of lights involved or the amount of heat created. A fan will easily facilitate the removal of hot, humid air inside a growroom replacing it with cool, dry air.

There are a number of reasons how the plant is affected by the gardener's ability to remove air effectively.   Chief amongst them would have to be the effect it has on CO_2.  Not only in relation to the amount available within the environment, but also to both the amount that can be taken into the plant and the rate at which it is processed.    It is common knowledge that CO₂ and light must be present in order for plants to photosynthesize, the process it uses to create energy.  It is a naturally occurring compound in the air, around 300 ppm.   However, with adequate lighting a garden can easily consume the CO₂ available indoors within a few hours.  By controlling temperature  the CO₂ depleted air is removed and cool, carbon dioxide rich air is added. When considering how CO₂ uptake is effected by temperature, a brief  examination of the leaf structure is necessary.   CO₂ is taken in through millions off microscopic openings located on the undersides of the leaves known as stomata.   It is here that carbon dioxide is absorbed by the plant and taken within the interior of the plant in order to be combined with chloroplast and water to form Adenosine Triphosphate (ATP) the major source of usable chemical energy in metabolism.  ATP is a compound that can be transported and broken down to be used for energy needed for development. In respect to the stomata humidity and temperature ranges are of great consequence, but it is the latter that is of a primary concern.   Just, as it can speed up the metabolic rate in animals, so too can it affect plants. Air temperatures within the range of 65-80º Fahrenheit are usually good parameters to seek within an indoor garden. The upper daytime limit can be raised to 85ºF or more when CO₂ is supplemented.  In fact, the processing of CO₂ is directly affected by temperature.  Some experiments have shown a rise of 20-30ºF can increase the rate of photosynthesis dramatically by increasing the speed at which carbon is taken from the CO₂, thus increasing the amount of energy available.  Of course this relationship is not infinite!  A limit is reached, not too far above the 90º F mark. Once core leaf temperature rises to this point, the stomata will close in order to curtail excessive transpiration. This effectively starves the plant of CO₂ consequentially having a disastrous effect on yield.    Temperature in many respects can be seen as linchpin.  If kept within range transpiration will occur keeping stomata open, which will allow the plant to absorb the much needed CO₂.

Most simply put, transpiration is the evaporation of water through the plant.  Water is taken in through the roots because of osmotic pressure and sent up into the body of the plant, into the leaves, and in the end released through the stomata.   It is through this process that nutrients taken into the plant and sugars created through photosynthesis are cycled throughout the plant. With this process occurring throughout the day a number of gallons of water can be evaporated into a growroom having a direct effect on humidity.  Plants that are reacting to higher temperatures attempt to cool themselves through transpiration.   Hence, the temperature will increase the rate of transpiration directly affecting the humidity of the environment as well.

Most plants indoors would prefer relative humidity ranges of  40-60 % because it is within that optimum CO₂ absorption occurs.   As relative humidity grows beyond the 60% level, the stomata's ability to absorb it is retarded.  It is mentioned above why CO₂ is important to plant development, but because of the effect high humidity has on stomata, it is also a concern

A far more serious issue arrives when moist warm air is cooled to low temperatures. This occurs when the light(s) go into the off-cycle, eliminating the heat created by the bulb. Atmospheric temperature must be monitored and controlled within the room.  As in the outdoors there needs to be an air temperature differential between the plant's perceived daytime and nighttime.  When there is light the plant considers it daytime and the temperature should be maintained around 18 - 25^oC and night time is 12 - 18^oC.  (This may vary slightly for different plants).  An independent thermostat should be placed among your plants to ensure temperature regulation. When the temperature is left to drop more than 10-15º F in a humid environment condensation occurs. Basically, this temperature change affects the relative humidity or how much water the air may hold. When the drop is too sudden, the volume of air's capacity to hold water vapour is lowered and water vapour becomes liquid ending up covering the surfaces of the growroom.  These water droplets allow a number of fungi and moulds to colonize, powdery mildew being the most common.  These reproduce by releasing spores that can spread throughout the foliage and if left unchecked will decimate the plants.  Once these populations are present, a number of different products can be used to control them. The removal plant material and wash down with a bleaching agent may be necessary.  The best approach is to ensure all hot air is exhausted from the room. 

It is by moving air that one can take control over the humidity in the room.   It can be done in a number ways with various rates of efficacy. The simplest is to purchase a humidistat and a fan. By not allowing the humidity to build one escapes excessive condensation.  Removing this air is essential, but equally important is moving fresh air throughout the garden canopy.

The foliage of the plants' is the area where all the aspects mentioned above come into play, and so the air within must be oscillated.  By bringing in an oscillating fan or two the gardener will help to mix the air within the room, helping to create more uniform temperature and humidity.  By mixing the cooler air from outside the area of the canopy with that within will reduce the humidity around the plants keeping the stomata open.  There is additional benefit here, in that this new air is rich with carbon dioxide.
Photosynthesis is the manufacture of sugar from two simple raw materials - carbon dioxide and water - in the presence of chlorophyll with sunlight (or artificial light) as the source of energy. Carbon dioxide (CO₂) is vital to the plants survival.  The normal atmospheric level is about 300 parts per million (ppm).Research has shown that plants are able to use more CO₂ than is available in the atmosphere (up to 1500 ppm) to grow larger and faster. CO2 enrichment in your grow room has the potential to dramatically increase your yield. 

Atmospheric temperature must be monitored and controlled within the room.  As in the outdoors there needs to be an air temperature differential between the plant's perceived daytime and nighttime.  When there is light the plant considers it daytime and the temperature should be maintained around 18 - 25^oC and night time is 12 - 18^oC.  (This may vary slightly for different plants).  An independent thermostat should be placed among your plants to ensure temperature regulation. 

Oscillating air will also have an effect on a number of garden pests that become uncomfortable under a breeze. The most common and devastating pest you will find indoors is the spider mite.  

This microscopic spider's metabolism is increased with temperature reducing the time it takes for them to reach sexual maturity.  When one is dealing with a population that grows exponentially, it can become beyond control in a short period of time.  To shed a little more light on it, a spider mite living in conditions around 45º F will take around 25 days to produce an egg from the time it born.  If the temperature is doubled to 90ºF the number of days will fall to about five. As well, the number of eggs that a female can lay will increase as the temperature increases.

Electrical conductivity (EC)
Electrical conductivity (EC), measured in milliMhos, is the measure of electrical conductance of the total dissolved solutes (minerals) in the solution.  The optimum EC range varies among different plants.  While EC measures the total dissolved minerals in a solution it does not identify the amounts of specific elements present. Therefore, it is easier to achieve the ideal EC using premixed hydroponic nutrients formulations than attempting to create your own formula using individual components. Nutrients are the sole source of nutrition for your plants. In general there are two types of nutrients available to the Hydroponic grower. A 'Grow' mix (high in nitrogen) and a 'Bloom' mix (high in potassium and phosphorous and . Plant nutrients are dissolved in the water used in hydroponics and are mostly in inorganic and ionic form. It is necessary to change the nutrient solution weekly to ensure that plants receive the specific elements required. EC testers are the most accurate way of monitoring and maintaining a desirable nutrient level in your reservoir.

pH
Plants will change the composition of the nutrient solutions upon contact by depleting specific nutrients more rapidly than others, removing water from the solution, and altering the pH by excretion of either acidity or alkalinity. Care is required not to allow salt concentrations to become too high, nutrients to become too depleted, or pH to wander far from the desired value. The pH level refers to the ‘Acid’ or ‘Alkaline’ level of the nutrient solution. The pH scale ranges from 0 to 14 with anything below seven considered ‘Acidic’. Most plants prefer a pH level of between 5.5 and 6.5. A pH level that is too high or too low can affect the plants ability to use the nutrients.

Grow media
One of the most obvious decisions a hydroponicist has to make is which medium they should use. Different media are appropriate for different growing techniques.

Clay Pebbles
Clay pebbles are small, round baked spheres of clay that are inert and are suitable for hydroponic systems in which all the nutrients are carefully controlled in the water. Clay pebbles are best not reused as even when they are cleaned. This does not remove roots that actually grow into clay beads. Breaking open a clay pebble after a crop has been grown in it will reveal this. Baked clay pebbles are porous, and can be irregularly shaped or uniform depending on brand and manufacturing process.
Rockwool
Rockwool is probably the most widely used medium in Hydroponics. Made from rock which has been melted and spun into fibrous cubes and growing slabs with the texture of insulation, Rockwool provides roots with a good balance of water/oxygen. Small cubes are used for starting seeds and cuttings and then transplanted into larger cubes once rooted. Rockwool can be used with NFT, dripper or flood and drain systems. Although it is possible to sterilize and re-use Rockwool, most often it is used only once. Rockwool will cause a higher pH level. You must adjust the pH level of the nutrient solution to counteract this. A pH level of 5.5-6.5 should suffice to create a suitable pH.
Coir
Coir is made from the refined husks of coconuts and is used in pot culture where its airy properties provide an ample supply of oxygen to the plants roots.
Perlite
Perlite is a volcanic rock that has been superheated into very lightweight expanded glass pebbles. It is used loose or in plastic sleeves immersed in the water. It is also used in potting soil mixes to decrease soil density. Perlite has similar properties and uses to vermiculite but generally holds more air and less water. If not contained, it can float if flood and drain feeding is used. It can be used alone as growing medium, but doesn't provide enough anchorage for large plants. Perlite is often used to start seed and cuttings, which can be easily transplanted after rooting.
Vermiculite
Like perlite, vermiculite is another mineral that has been superheated until it has expanded into light pebbles. Vermiculite holds more water than perlite and has a natural "wicking" property that can draw water and nutrients in a passive hydroponic system. If too much water and not enough air surrounds the plants roots, it's possible to gradually lower the medium's water-retention capability by mixing in increasing quantities of perlite.

All these things are controlled by you, the grower.  With everything taken into consideration your grow room should reward you with an easily maintained system and produce an unending yields

Present and future

With pest problems reduced, and nutrients constantly fed to the roots, productivity in hydroponics is high, plant growth being limited by the low levels of carbon dioxide in the atmosphere, or limited light. To increase yield further, some sealed greenhouses inject carbon dioxide into their environment to help growth (CO₂ enrichment), or add lights to lengthen the day, control vegetative growth etc.

Hydroponics can be used to grow plants anywhere, from Antartica (where salad vegetables are grown in the 6 month nights) to a coal mine. If vegetables are grown in future space missions, it is likely to be by hydroponic methods.

The fact that plants can be grown almost anywhere, with no natural light by using hydroponics and artificial lighting, has not escaped the notice of cannabis cultivators, and a large amount of hydroponics equipment appears to be in use for this purpose.

3 Counties has been working diligently to reduce the stigma of these types of activities. We are actively promoting outdoor hydroponics in an effort to show gardeners how simple, fun, and productive it is to grow food hydroponically in their own backyards.