R
Reeferman
Guest
Here is a great article I found for new cats and old cats it covers basics of electric loads and much much more !
Growroom Tips and Safety
Electrical Safety for the Indoor Growrooms
One of the commonly asked questions regarding electrical and gardening with High Intensity Discharge (HiD) lighting is "how many 1000 watt lights can run on this set?" Generally an outlet on your bedroom or basement wall is part of a 15 amp circuit. There are up to 12 lights and or plugs on that circuit. A 1000w HPS or Metal Halide light takes 9 amps at 120 volts so you can only run one on a wall outlet circuit. A standard dryer outlet is 220 volts and 30 amps so you can power up to six 1000 watt lights on that circuit. A range outlet is typically 40 amps on an older house and 50 amps on a new house. Therefore you could run up to eight lights and 10 lights respectively. The important thing to check first is the breaker size for the circuit you want to use. The breaker is sized to protect the wire and then anything plugged into the circuit. Below is a table used to size wire for whatever load you have.
You must note that for safety, the Canadian Electrical Code states that you can only load circuits up to 80% of their recommended capability.
Another common question is "Should I run my lights on 110 volts or 220 volts?" The answer is that it makes no difference - a 1000 watt ballast uses nine amps at 110 volts or 4.5 amps at 220 volts go on a typical dryer outlet. You can run six lights at 4.5 amps, 220 volts for a total of 27 amps, 220 volts or six lights at 9 amps 110 volts (three lights each side of the 220 volt circuit) for 27 amps at 110 volts and 27 amps on the other 110 volts.
Note: A 220 volt circuit is a three wire circuit with two hotwires and a shared neutral (white) wire so that there would be 27 amps on each hot wire for a total of 27 amps at 220 volts. If you are still in doubt about what you can do, there are lots of good books on the subject at your local library or ask your local gardening store specialist.
Chart for Electrical Safety
15 amps . . . .
20 amps . . . .
30 amps . . . .
45 amps . . . .
65 amps . . . .
85 amps . . . .
100 amps . . . .
115 amps . . . .
130 amps . . . .
14 GA . . . .
12 GA . . . .
10 GA . . . .
8 GA . . . .
6 GA . . . .
4 GA . . . .
3 GA . . . .
2 GA . . . .
1 GA . . . .
15 amp . . . .
20 amp . . . .
30 amp . . . .
40 amp . . . .
60 amp . . . .
70 amp . . . .
100 amp . . . .
100 amp . . . .
125 amp . . . .
When growing indoors one must, for all intent and purposes, provide the essentials for plant life. When taking a brief survey most will pay heed to providing proper nutrition, Carbon Dioxide (CO 2 ) and light, the basis for photosynthesis and consequently plant growth.
Growrooms are always a development in progress and as such many indoor gardeners have pondered what new piece of equipment or additive to experiment with next. Often an equipment upgrade or additional HID lamp will head the list. Many times it is the wrong choice. Man is often guilty of thinking, ‘more is better.’ In this case, any of the aforementioned should not hold consideration if proper attention has not been given to the garden environment. Yes, it is the exhaust fan that 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 CO 2 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. Complete control can be a formidable accomplishment during the winter months, however, any effort put toward the cause will be rewarded handsomely.
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 exhaust 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.
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.
In the summer it often becomes imperative to control the heat created more effectively. Many times an air-cooled reflector with a separate exhaust fan is the answer. This will remove the heat from the bulb before it is able to increase the temperature of the garden area. An additional benefit of this method is the ability to bring lights closer to the plants increasing the total number of lumens available.
At other times, air-cooled systems are not enough, and it becomes necessary to introduce an air conditioner or heat exchanger. These options come at a significant cost. However, these costs can be deemed inconsequential when considering the amount of grief that can be prevented by buffering your indoor gardens from high temperatures and humidity, conditions that can have a detrimental effect on the plant’s ability to function.
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 CO 2 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 CO 2 available indoors within a few hours. By controlling temperature the CO 2 depleted air is removed and cool, carbon dioxide rich air is added.
When considering how CO 2 uptake is effected by temperature, a brief examination of the leaf structure is necessary. CO 2 is taken in through millions of 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 CO 2 is supplemented. In fact, the processing of CO 2 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 CO 2 , 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 CO 2 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 CO 2 .
When considering transpiration CO 2 is not the only concern. 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 CO 2 absorption occurs. As relative humidity grows beyond the 60% level, the stomata’s ability to absorb it is retarded. It is mentioned above why CO 2 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. 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 garden room. 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. These will, however, only limit the damage and sometimes a fresh start is what is needed. The removal plant material and wash down with a bleaching agent may be necessary. The best approach is to nip the problem in the bud and 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. Arguable the simplest is to purchase a humidistat and a fan or if warranted a dehumidifier, allowing for establishment of upper humidity controls. 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.
Oscillating air will also have an effect on a number of garden pests that become uncomfortable under a breeze. There are too many varieties of pests that can reek havoc on an indoor garden to discuss in full here, however, there is space to explore one example, perhaps the most common and devastating: 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.
It all comes back to the temperature/humidity issue. That is the primary reason for moving air in any garden. The above is no more than a brief synopsis, listing some of the benefits gained from moving air. It is therefore imperative not to ignore the climate within your growroom even if at times it is tempting to add another light or more additives with any extra money one might have.
Elevating carbon dioxide levels can increase growth speed a great deal, perhaps even double it. It seems that the plant evolved in primordial times when natural CO 2 levels were many times what they are today. The plant uses CO 2 for photosynthesis to create sugars it uses to build plant tissues. Elevating the CO 2 level will increase the plants ability to manufacture these sugars and plant growth rate is enhanced considerably.
CO 2 can be a pain to manufacture safely, cheaply, and / or conveniently, and is expensive to set up if you use a CO 2 tank system. CO 2 is most usable for flowering, as this is when the plant is most dense and has the hardest time circulating air around its leaves. If you’re strictly growing vegetatively indoors, (transferring your plants outdoors to flower), then CO 2 will not be a major concern unless you have a sealed greenhouse or growroom, and wish to increase yield while decreasing flowering time.
For a medium sized indoor operation, one approach is to use CO 2 canisters from welding supply houses. This is expensive initially, but fairly inexpensive in the long run. These systems are good only if your area is not too big or too small.
The basic CO 2 tank system consists of a 20 lb tank, regulator and a timer or controller. You can expect to pay somewhere in the neighbourhood of $400 to $500 for your initial set-up. After that, filling your tank will cost you somewhere in the area of $20 to $25.
CO 2 is cheaply produced by burning Natural Gas. However, heat and Carbon Monoxide must be vented to the outside air. CO 2 can be obtained by buying or leasing cylinders from local welding supply house.
For a small enclosed growroom, one tank could last two months, but it depends on how much is released, how often the room is vented, hours of light cycle, room leaks, enrichment levels and dispersion methods. This method may be overkill for such a small venture.
It is generally viewed as good to have a small constant flow of CO 2 over the plants at all times the lights are on, dispersed directly over the plants during the time exhaust fans are off.
Opportunities exist to conserve CO 2, but this can cost money. When the light is off you don’t need CO 2, so during flowering, you will use half as much if you have the CO 2 solenoid setup to your light timer. When the fan is on for venting, CO 2 is shut off as well. This may be up to half the time the light is on, so this will affect the plants exposure times and amount of gas actually dispensed.
Environmentally, using bottled gas is better, since manufacturing it adds to the greenhouse effect, and bottled CO 2 is captured as part of the manufacturing process of many materials, and then recycled. Fermenting, CO 2 generators, and baking soda and vinegar methods all generate new CO 2 and add to the greenhouse effect.
CO 2 generation from fermentation and generators is possible. A simple CO 2 generator would be a propane heater. This will work well, as long as the gases can be vented to the grow area, and a fan is used to keep the hot CO 2 (that will rise) circulating and available below at the plants level. Fire and exhaust venting of the heat are issues as well. A room that must be vented 50% of the time to rid the environment of heat from a lamp and heater will not receive as much CO 2 as a room that can be kept unvented for hours at a time. However, CO 2 generators are the only way to go for most large scale operations.
Fermentation or vinegar over baking soda will work if you don’t have many vent cycles. However, if you have enough heat to make constant or regular venting necessary, these methods become impractical. Just pour the vinegar on baking soda and close the door, (you lose your CO 2 as soon as the vent comes on). This method leaves a great deal to be desired, since it is not easy to regulate automatically, and requires daily attention. It is possible however, to create CO 2 by fermentation. Let wine turn to vinegar, and pour this on baking soda. It’s the most cost-effective setup for hobby growers, for whom $400 in CO 2 equipment is a bit much to swallow.
In fermentation, yeast is constantly killing itself; it takes a lot of space. You need a big bin to constantly keep adding water to, so that the alcohol levels will not rise high enough to kill the yeast. Sugar is used quickly this way, and a 10 pound sack will run $3.50 or so and last about two to three weeks. This is also difficult to gauge what is happening as far as what amounts are actually released. A tube out the top going into a jar of water will bubble and at least visually demonstrate the amount of CO 2 being produced.
Try sodium bicarbonate mixed with vinegar, 1 tsp (~30cc). This will gush up all frothy as it releases CO 2. Do it just before you close the door on your plants. A much cheaper way to provide CO 2 is accomplished by dissolving two ounces of suger in two litres of water in a bottle [sterilized first with bleach and water, then rinsed], plus a few cc’s of urine (Hey, its not just for relieving the sting of a jellyfish bite.), or if you insist, yeast nutrient from a home brewing supplier. Add a brewing yeast, shake up and keep at 25 degrees Celsius (~70 F). Over the next two weeks or so it will brew up about ½ Ounce of CO 2 for every Ounce of sugar used. Keep a few going at once, starting a new one every three days or so. With added CO 2, growth is phenomenal if done correctly.
As far as a good homemade container for your CO 2 machine, a one gallon plastic milk jug with a pin-hole in the cap will work just fine. Also, the air-lock from a piece of clear tube running into a jar filled with water will keep microbes out and demonstrate that the fermentation is working.
A variation is to spray seltzer water on the plants twice a day. This is not recommended by some authorities, and receives great raves by people who seem to feel it has enhanced their crop. It stands to reason this would work for only a small unvented growroom, but may be right for some larger gardens. However, It could get expensive with a lot of plants to spray.
Use seltzer, not club soda, since it contains less sodium that could clog the plants stomata. Wash your plants with straight water after two or three seltzer sprays. It’s a lot of work, and you can’t automate it, but it does keep you directly in control. Seltzer is available at most grocery stores. Club soda will work if seltzer water is not available; but it has twice the amount of sodium in it. A very diluted solution of Miracle Grow can be sprayed on the plant at the same time. One factor of using selzter water is it raises humidity levels. Make sure your venting humidity during the dark cycle, or you could risk fungus and increased internode length.
CAUTION: Don’t spray too close to a hot bulb! Spray downward only, or turn off the lamp first.
Even though CO 2 enrichment can mean 30-100% yield increases, the hassle, expense, space, danger, and time involved can make constant or near constant venting a desirable alternative to enrichment. As long as the plant has the opportunity to take in new CO 2 at all times from air that is over 200 ppm CO 2, the plants will have the required nutrients for photosynthesis. Most small, enclosed grow areas will need new CO 2 coming in every two or three hours, minimum.
Most cities will have high concentrations of CO 2 in the air, and some growers find CO 2 injection unnecessary in these circumstances.
In having an indoor garden it is almost inevitable that sooner or later you will experience problems with plant growth. When this happens you have two choices on where to find the answers, you can look up the problem in a book at the library or information on the internet. This is a good source of information if you have a reasonable knowledge of plants and indoor gardening. The other way is to seek out help from a professional. The best place to find someone who can help you with your problems is at your local hydroponics store. These people deal with problems like yours every day and should be able to sort out your troubles.
There is a standard list of questions that they will ask you about your indoor garden and it will help speed up the process if you have the answers. The following questions will help you to determine what area your problems exist in and save everyone time in rectifying them.
What size is your growroom.
How many lights and what type are they.
What type of system are you using.
What type of medium is being used.
What is the day and night time temperature.
What is the temperature of your nutrient solution <recirculating systems>
What is the pH value of the nutrient solution and the medium.
What is the strength of the nutrient <TDS> and what type.
Specific Problems
What is happening in your garden <a general description>
When did the problem first occur.
What stage of growth are the plants in. <vegetative or flowering>
Did the problem start on one plant and spread or where all plants affected at the same time.
What do the leaves look like <curled, dry, burnt, ect.>
Are only certain areas of the plant effected. <top leaves, bottom leaves, flowers, roots>
Have you seen any bugs on the bottom or top of leaves or in the medium.
Have you done anything different.<changed nutriant, ph, tds strength>
Have you sprayed the plants with anything recently.<foiliar spray, insecticide, fungicide.>
By having answers to these questions ready when you seek out help you will greatly reduce the time it will take to solve your indoor gardening problems.
The Odour Problem
Often an arrival to a hydroponic growroom is preceded by its odor.
A lot of research, effort and attention has been devoted to the stale, damp odors that can emanate from hydroponic gardening.
Ionization, chemical deodorizers and ozone systems have all been touted to treat the situation, but before discussing the correct solution, let's first analyze the problem. Typically, a hobbyist has a grow room set up in an area of the home which is not environmentally isolated. Therefore, the entering and exiting of the hydroponic grow room allows odors to spread throughout the home. Additionally, the lighting in the hydroponic grow room creates an enormous amount of heat which, along with the stale odors, is exhausted to the outdoors. The ideal solution would provide a home with air that is naturally fresh and clean smelling with neutral hydroponic system exhaust. Essentially, no detectable odors in or outside the home. When correctly employed, ozone air treatment is the one solution that meets these critical demands.
We have all experienced the exhilarating effects and the clean fresh fragrance of the air after a thunder storm. The spice of this fragrance is ozone. Ozone (03), a triatomic (3 atoms) form of oxygen, is a normal trace element in the earth's atmosphere. It is created by the action of short-wave length ultraviolet light from the sun on the oxygen in the air (the ozone layer in our stratosphere). It is also created in nature by lightning and man-made through electrical discharges (sophisticated automotive "spark plugs") such as arc welding.
Chemical deodorizers merely mask odors and ionizers only charge air particles so that they fall to the earth. Beyond providing its own fresh air aroma, ozone actually binds with the odor molecules to neutralize odors at the source. Natural low levels of O3 are in the air we breath at all times. The maximum level of O3 in the air that all government regulatory agencies consider 100% safe for people, plants and pets is 0.05 ppm. O3 levels are accurately tested with an "Eco Badge," an inexpensive test kit used to establish an initial ozone level at which odor is effectively eliminated without any side effects (light headedness, headaches, dry throat and in the extreme, nausea) that may be caused from high concentrations.
HOME
To prevent the escape of odor to the other areas of the home, only ultra-violet (UV) ozone lamp generators should be used. A 0.05 ppm level inside the grow room is recommended. UV ozonators (14" bulb length or less in length) produce appropriate levels of O3. Another benefit to low levels of ozone in the grow room is the small amounts of CO2 being created by the ozone's oxidization of the organic debris in the air.
COMMERCIAL
When outside ventilation is used, an adjustable corona discharge system is the answer. An exhaust system requires a more sophisticated, variable output O3 system. The level of odor intensifies as plants grow to maturity, therefore, it is necessary to increase the O3 output gradually. Heat is the enemy of O3 and therefore the O3 output must be increased as the heat increases. UV ozonators are not adjustable and so only electronic corona discharge systems will provide the adjustable high levels of O3 required. As the heat and odors increase, the electronic ozonator is adjusted with the turn of a knob to the increasing amount of O3 required to provide a fresh air scent at the exhaust outlet.
A well managed and properly equipped ozone air care program will control odors and increase the success and overall enjoyment of hydroponic gardening.
Copyright 2005.The Green Thumb. All rights reserved. Designed and Hosted by GT Technical Solutions [email protected] 484-241-0163
Growroom Tips and Safety
Electrical Safety for the Indoor Growrooms
One of the commonly asked questions regarding electrical and gardening with High Intensity Discharge (HiD) lighting is "how many 1000 watt lights can run on this set?" Generally an outlet on your bedroom or basement wall is part of a 15 amp circuit. There are up to 12 lights and or plugs on that circuit. A 1000w HPS or Metal Halide light takes 9 amps at 120 volts so you can only run one on a wall outlet circuit. A standard dryer outlet is 220 volts and 30 amps so you can power up to six 1000 watt lights on that circuit. A range outlet is typically 40 amps on an older house and 50 amps on a new house. Therefore you could run up to eight lights and 10 lights respectively. The important thing to check first is the breaker size for the circuit you want to use. The breaker is sized to protect the wire and then anything plugged into the circuit. Below is a table used to size wire for whatever load you have.
You must note that for safety, the Canadian Electrical Code states that you can only load circuits up to 80% of their recommended capability.
Another common question is "Should I run my lights on 110 volts or 220 volts?" The answer is that it makes no difference - a 1000 watt ballast uses nine amps at 110 volts or 4.5 amps at 220 volts go on a typical dryer outlet. You can run six lights at 4.5 amps, 220 volts for a total of 27 amps, 220 volts or six lights at 9 amps 110 volts (three lights each side of the 220 volt circuit) for 27 amps at 110 volts and 27 amps on the other 110 volts.
Note: A 220 volt circuit is a three wire circuit with two hotwires and a shared neutral (white) wire so that there would be 27 amps on each hot wire for a total of 27 amps at 220 volts. If you are still in doubt about what you can do, there are lots of good books on the subject at your local library or ask your local gardening store specialist.
Chart for Electrical Safety
15 amps . . . .
20 amps . . . .
30 amps . . . .
45 amps . . . .
65 amps . . . .
85 amps . . . .
100 amps . . . .
115 amps . . . .
130 amps . . . .
14 GA . . . .
12 GA . . . .
10 GA . . . .
8 GA . . . .
6 GA . . . .
4 GA . . . .
3 GA . . . .
2 GA . . . .
1 GA . . . .
15 amp . . . .
20 amp . . . .
30 amp . . . .
40 amp . . . .
60 amp . . . .
70 amp . . . .
100 amp . . . .
100 amp . . . .
125 amp . . . .
When growing indoors one must, for all intent and purposes, provide the essentials for plant life. When taking a brief survey most will pay heed to providing proper nutrition, Carbon Dioxide (CO 2 ) and light, the basis for photosynthesis and consequently plant growth.
Growrooms are always a development in progress and as such many indoor gardeners have pondered what new piece of equipment or additive to experiment with next. Often an equipment upgrade or additional HID lamp will head the list. Many times it is the wrong choice. Man is often guilty of thinking, ‘more is better.’ In this case, any of the aforementioned should not hold consideration if proper attention has not been given to the garden environment. Yes, it is the exhaust fan that 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 CO 2 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. Complete control can be a formidable accomplishment during the winter months, however, any effort put toward the cause will be rewarded handsomely.
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 exhaust 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.
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.
In the summer it often becomes imperative to control the heat created more effectively. Many times an air-cooled reflector with a separate exhaust fan is the answer. This will remove the heat from the bulb before it is able to increase the temperature of the garden area. An additional benefit of this method is the ability to bring lights closer to the plants increasing the total number of lumens available.
At other times, air-cooled systems are not enough, and it becomes necessary to introduce an air conditioner or heat exchanger. These options come at a significant cost. However, these costs can be deemed inconsequential when considering the amount of grief that can be prevented by buffering your indoor gardens from high temperatures and humidity, conditions that can have a detrimental effect on the plant’s ability to function.
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 CO 2 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 CO 2 available indoors within a few hours. By controlling temperature the CO 2 depleted air is removed and cool, carbon dioxide rich air is added.
When considering how CO 2 uptake is effected by temperature, a brief examination of the leaf structure is necessary. CO 2 is taken in through millions of 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 CO 2 is supplemented. In fact, the processing of CO 2 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 CO 2 , 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 CO 2 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 CO 2 .
When considering transpiration CO 2 is not the only concern. 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 CO 2 absorption occurs. As relative humidity grows beyond the 60% level, the stomata’s ability to absorb it is retarded. It is mentioned above why CO 2 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. 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 garden room. 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. These will, however, only limit the damage and sometimes a fresh start is what is needed. The removal plant material and wash down with a bleaching agent may be necessary. The best approach is to nip the problem in the bud and 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. Arguable the simplest is to purchase a humidistat and a fan or if warranted a dehumidifier, allowing for establishment of upper humidity controls. 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.
Oscillating air will also have an effect on a number of garden pests that become uncomfortable under a breeze. There are too many varieties of pests that can reek havoc on an indoor garden to discuss in full here, however, there is space to explore one example, perhaps the most common and devastating: 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.
It all comes back to the temperature/humidity issue. That is the primary reason for moving air in any garden. The above is no more than a brief synopsis, listing some of the benefits gained from moving air. It is therefore imperative not to ignore the climate within your growroom even if at times it is tempting to add another light or more additives with any extra money one might have.
Elevating carbon dioxide levels can increase growth speed a great deal, perhaps even double it. It seems that the plant evolved in primordial times when natural CO 2 levels were many times what they are today. The plant uses CO 2 for photosynthesis to create sugars it uses to build plant tissues. Elevating the CO 2 level will increase the plants ability to manufacture these sugars and plant growth rate is enhanced considerably.
CO 2 can be a pain to manufacture safely, cheaply, and / or conveniently, and is expensive to set up if you use a CO 2 tank system. CO 2 is most usable for flowering, as this is when the plant is most dense and has the hardest time circulating air around its leaves. If you’re strictly growing vegetatively indoors, (transferring your plants outdoors to flower), then CO 2 will not be a major concern unless you have a sealed greenhouse or growroom, and wish to increase yield while decreasing flowering time.
For a medium sized indoor operation, one approach is to use CO 2 canisters from welding supply houses. This is expensive initially, but fairly inexpensive in the long run. These systems are good only if your area is not too big or too small.
The basic CO 2 tank system consists of a 20 lb tank, regulator and a timer or controller. You can expect to pay somewhere in the neighbourhood of $400 to $500 for your initial set-up. After that, filling your tank will cost you somewhere in the area of $20 to $25.
CO 2 is cheaply produced by burning Natural Gas. However, heat and Carbon Monoxide must be vented to the outside air. CO 2 can be obtained by buying or leasing cylinders from local welding supply house.
For a small enclosed growroom, one tank could last two months, but it depends on how much is released, how often the room is vented, hours of light cycle, room leaks, enrichment levels and dispersion methods. This method may be overkill for such a small venture.
It is generally viewed as good to have a small constant flow of CO 2 over the plants at all times the lights are on, dispersed directly over the plants during the time exhaust fans are off.
Opportunities exist to conserve CO 2, but this can cost money. When the light is off you don’t need CO 2, so during flowering, you will use half as much if you have the CO 2 solenoid setup to your light timer. When the fan is on for venting, CO 2 is shut off as well. This may be up to half the time the light is on, so this will affect the plants exposure times and amount of gas actually dispensed.
Environmentally, using bottled gas is better, since manufacturing it adds to the greenhouse effect, and bottled CO 2 is captured as part of the manufacturing process of many materials, and then recycled. Fermenting, CO 2 generators, and baking soda and vinegar methods all generate new CO 2 and add to the greenhouse effect.
CO 2 generation from fermentation and generators is possible. A simple CO 2 generator would be a propane heater. This will work well, as long as the gases can be vented to the grow area, and a fan is used to keep the hot CO 2 (that will rise) circulating and available below at the plants level. Fire and exhaust venting of the heat are issues as well. A room that must be vented 50% of the time to rid the environment of heat from a lamp and heater will not receive as much CO 2 as a room that can be kept unvented for hours at a time. However, CO 2 generators are the only way to go for most large scale operations.
Fermentation or vinegar over baking soda will work if you don’t have many vent cycles. However, if you have enough heat to make constant or regular venting necessary, these methods become impractical. Just pour the vinegar on baking soda and close the door, (you lose your CO 2 as soon as the vent comes on). This method leaves a great deal to be desired, since it is not easy to regulate automatically, and requires daily attention. It is possible however, to create CO 2 by fermentation. Let wine turn to vinegar, and pour this on baking soda. It’s the most cost-effective setup for hobby growers, for whom $400 in CO 2 equipment is a bit much to swallow.
In fermentation, yeast is constantly killing itself; it takes a lot of space. You need a big bin to constantly keep adding water to, so that the alcohol levels will not rise high enough to kill the yeast. Sugar is used quickly this way, and a 10 pound sack will run $3.50 or so and last about two to three weeks. This is also difficult to gauge what is happening as far as what amounts are actually released. A tube out the top going into a jar of water will bubble and at least visually demonstrate the amount of CO 2 being produced.
Try sodium bicarbonate mixed with vinegar, 1 tsp (~30cc). This will gush up all frothy as it releases CO 2. Do it just before you close the door on your plants. A much cheaper way to provide CO 2 is accomplished by dissolving two ounces of suger in two litres of water in a bottle [sterilized first with bleach and water, then rinsed], plus a few cc’s of urine (Hey, its not just for relieving the sting of a jellyfish bite.), or if you insist, yeast nutrient from a home brewing supplier. Add a brewing yeast, shake up and keep at 25 degrees Celsius (~70 F). Over the next two weeks or so it will brew up about ½ Ounce of CO 2 for every Ounce of sugar used. Keep a few going at once, starting a new one every three days or so. With added CO 2, growth is phenomenal if done correctly.
As far as a good homemade container for your CO 2 machine, a one gallon plastic milk jug with a pin-hole in the cap will work just fine. Also, the air-lock from a piece of clear tube running into a jar filled with water will keep microbes out and demonstrate that the fermentation is working.
A variation is to spray seltzer water on the plants twice a day. This is not recommended by some authorities, and receives great raves by people who seem to feel it has enhanced their crop. It stands to reason this would work for only a small unvented growroom, but may be right for some larger gardens. However, It could get expensive with a lot of plants to spray.
Use seltzer, not club soda, since it contains less sodium that could clog the plants stomata. Wash your plants with straight water after two or three seltzer sprays. It’s a lot of work, and you can’t automate it, but it does keep you directly in control. Seltzer is available at most grocery stores. Club soda will work if seltzer water is not available; but it has twice the amount of sodium in it. A very diluted solution of Miracle Grow can be sprayed on the plant at the same time. One factor of using selzter water is it raises humidity levels. Make sure your venting humidity during the dark cycle, or you could risk fungus and increased internode length.
CAUTION: Don’t spray too close to a hot bulb! Spray downward only, or turn off the lamp first.
Even though CO 2 enrichment can mean 30-100% yield increases, the hassle, expense, space, danger, and time involved can make constant or near constant venting a desirable alternative to enrichment. As long as the plant has the opportunity to take in new CO 2 at all times from air that is over 200 ppm CO 2, the plants will have the required nutrients for photosynthesis. Most small, enclosed grow areas will need new CO 2 coming in every two or three hours, minimum.
Most cities will have high concentrations of CO 2 in the air, and some growers find CO 2 injection unnecessary in these circumstances.
In having an indoor garden it is almost inevitable that sooner or later you will experience problems with plant growth. When this happens you have two choices on where to find the answers, you can look up the problem in a book at the library or information on the internet. This is a good source of information if you have a reasonable knowledge of plants and indoor gardening. The other way is to seek out help from a professional. The best place to find someone who can help you with your problems is at your local hydroponics store. These people deal with problems like yours every day and should be able to sort out your troubles.
There is a standard list of questions that they will ask you about your indoor garden and it will help speed up the process if you have the answers. The following questions will help you to determine what area your problems exist in and save everyone time in rectifying them.
What size is your growroom.
How many lights and what type are they.
What type of system are you using.
What type of medium is being used.
What is the day and night time temperature.
What is the temperature of your nutrient solution <recirculating systems>
What is the pH value of the nutrient solution and the medium.
What is the strength of the nutrient <TDS> and what type.
Specific Problems
What is happening in your garden <a general description>
When did the problem first occur.
What stage of growth are the plants in. <vegetative or flowering>
Did the problem start on one plant and spread or where all plants affected at the same time.
What do the leaves look like <curled, dry, burnt, ect.>
Are only certain areas of the plant effected. <top leaves, bottom leaves, flowers, roots>
Have you seen any bugs on the bottom or top of leaves or in the medium.
Have you done anything different.<changed nutriant, ph, tds strength>
Have you sprayed the plants with anything recently.<foiliar spray, insecticide, fungicide.>
By having answers to these questions ready when you seek out help you will greatly reduce the time it will take to solve your indoor gardening problems.
The Odour Problem
Often an arrival to a hydroponic growroom is preceded by its odor.
A lot of research, effort and attention has been devoted to the stale, damp odors that can emanate from hydroponic gardening.
Ionization, chemical deodorizers and ozone systems have all been touted to treat the situation, but before discussing the correct solution, let's first analyze the problem. Typically, a hobbyist has a grow room set up in an area of the home which is not environmentally isolated. Therefore, the entering and exiting of the hydroponic grow room allows odors to spread throughout the home. Additionally, the lighting in the hydroponic grow room creates an enormous amount of heat which, along with the stale odors, is exhausted to the outdoors. The ideal solution would provide a home with air that is naturally fresh and clean smelling with neutral hydroponic system exhaust. Essentially, no detectable odors in or outside the home. When correctly employed, ozone air treatment is the one solution that meets these critical demands.
We have all experienced the exhilarating effects and the clean fresh fragrance of the air after a thunder storm. The spice of this fragrance is ozone. Ozone (03), a triatomic (3 atoms) form of oxygen, is a normal trace element in the earth's atmosphere. It is created by the action of short-wave length ultraviolet light from the sun on the oxygen in the air (the ozone layer in our stratosphere). It is also created in nature by lightning and man-made through electrical discharges (sophisticated automotive "spark plugs") such as arc welding.
Chemical deodorizers merely mask odors and ionizers only charge air particles so that they fall to the earth. Beyond providing its own fresh air aroma, ozone actually binds with the odor molecules to neutralize odors at the source. Natural low levels of O3 are in the air we breath at all times. The maximum level of O3 in the air that all government regulatory agencies consider 100% safe for people, plants and pets is 0.05 ppm. O3 levels are accurately tested with an "Eco Badge," an inexpensive test kit used to establish an initial ozone level at which odor is effectively eliminated without any side effects (light headedness, headaches, dry throat and in the extreme, nausea) that may be caused from high concentrations.
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To prevent the escape of odor to the other areas of the home, only ultra-violet (UV) ozone lamp generators should be used. A 0.05 ppm level inside the grow room is recommended. UV ozonators (14" bulb length or less in length) produce appropriate levels of O3. Another benefit to low levels of ozone in the grow room is the small amounts of CO2 being created by the ozone's oxidization of the organic debris in the air.
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When outside ventilation is used, an adjustable corona discharge system is the answer. An exhaust system requires a more sophisticated, variable output O3 system. The level of odor intensifies as plants grow to maturity, therefore, it is necessary to increase the O3 output gradually. Heat is the enemy of O3 and therefore the O3 output must be increased as the heat increases. UV ozonators are not adjustable and so only electronic corona discharge systems will provide the adjustable high levels of O3 required. As the heat and odors increase, the electronic ozonator is adjusted with the turn of a knob to the increasing amount of O3 required to provide a fresh air scent at the exhaust outlet.
A well managed and properly equipped ozone air care program will control odors and increase the success and overall enjoyment of hydroponic gardening.
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