WHAT NEEDS CONTROLLING?

If you are bothering to grow your plants indoors under HID lights, you probably care quite a bit about them and want them to be healthy and produce well for you. If this is the case, you need to be aware of the environmental factors that will affect your plants’ growth the most. Probably the biggest problems associated with growing indoors are ventilation or carbon dioxide related. The current of air that circulates in a grow room is as important as light, water, heat and nutrient. Proper ventilation acts as a mediator between light and water, removing excess heat and humidity, while providing plants with a healthy supply of CO2.

The amount of control you will need to exercise over the environmental factors in your room will greatly depend on the scale of your growing area – the number of plants, the number of lights, the size of the room, and whether or not you are supplementing with CO2. We assume you are looking for the best possible quality fruits / flowers and yield. If this is the case, you need to be aware of the environmental factors that will affect your plants’ growth the most.

Environmental controllers ARE expensive, but they really do make a large difference. They keep the conditions at the perfect level for your plants and they will reward you with gorgeous and bountiful produce. With each environmental factor that is tuned in to the correct range, the plant growth will become that much healthier and robust.

You can achieve excellent results by using timers and innovation, however most commercial nurseries have automated climate controllers in their greenhouses. If you are growing plants for profit and want to compete on a commercial basis, chances are you would benefit from some automated controls as well. We go over the basics and necessities as well as some of our favorite choices below.
AUTOMATIC CLIMATE CONTROL

Let’s discuss what high-tech automated environmental control can do for you. Using high-tech equipment in a growing environment will both boost plant growth exponentially and ensure the health of your plants. Light is the limiting factor in any indoor growing system. For this reason, all other variables (nutrients, carbon dioxide, pH, temperature, humidity, etc.) should be raised to optimum levels to compensate for any light deficiency. In an optimal environment, plants are able to absorb what they need, when they need it, resulting in accelerated growth and vibrant health. This translates into larger yields of fruit or flowers at harvest time. The average hand-watering home gardener realizes about a 150% increase in productivity after switching to a controlled hydroponic system. As your sophistication grows, you can experience a 250% or more increase from these beginning base harvest levels.

An automated system controls not only light and watering cycles, but maintains optimal nutrient, pH and CO2 levels at all times as well. The difference this makes for plant growth is like the difference between sitting in bumper to bumper rush hour traffic versus driving an open highway when every song on the radio is one your favorites. Plants grow a lot faster with every important environmental factor tuned in. Automated controllers ARE expensive, but they really do make a large difference. They keep the conditions at the perfect level for your plants and they will reward you with gorgeous and boutiful produce. With each environmental factor that gets tuned in to the correct range, the plant growth becomes that much more healthy and robust.

By its very nature, hydroponics works well with technology. And in order for nature to thrive in an indoor environment, or in an environment that was up to now severely limiting –like a desert or a rooftop– a slew of problematic factors must be solved. High-tech tools and methods are the dependable and essential solution.

You can achieve excellent results by using timers and innovation, however most commercial nurseries have automated controllers in their greenhouses. If you are growing plants for profit and want to compete on a commercial base..chances are you would benefit from some automated controls as well. We believe that you will want to start small, with a pH and Nutrient Meter, and then work your way up to humidity and temperature control using vent fans. After upgrading your air control, you will probably be most interested in either a Nutrient/pH water flow management system or CO2. We have other info sheets detailing both of these categories.
AIR CIRCULATION

The current of air that circulates in a grow room is as important as light, water, heat and nutrient. Proper ventilation acts as a mediator between light and water, removing excess heat and humidity, while providing plants with a healthy supply of CO2. Probably the largest problems associated with growing indoors are ventilation or carbon dioxide related. Plants need CO2 to grow and thrive. They absorb it and use light to break it down into carbon and oxygen. Carbon is used to create new plant material and oxygen is released as a byproduct. A lack of CO2, found in musty grow rooms, encourages mold, invites algae and can turn plant leaves an hideous shade of yellow. This unhealthy environment eventually leads to stunted growth, withering and general plant malaise.

To provide ample CO2 to plants, fresh air must be brought in continually, or it can be supplied via a CO2 emitter or generator. Getting fresh air into your grow room can be as simple as an open hole with a screen, or a vent fan. (With CO2 enrichment, a fresh air intake is not necessary.) The circulation within the room should be constant and breezy. Plants breathe through their stomata which reside on the undersides of their leaves. Air must ruffle these leaves, providing fresh CO2 to their stomata. No stagnant air should be present.

In a closet or other small space, a small circulating fan should do the trick. For larger applications, an industrial fan should be positioned in such a manner as to facilitate a current of air which sweeps around the room in a circle. In a 10′ x 10′ space, one industrial fan combined with a wall mounted circulating fan should be sufficient. Larger spaces may need double or triple the amount of fans.
VENTING

Proper venting always takes at least one exhaust fan. With the help of flexible ducting, venting can be directed through roofs, around tight corners and even through walls. Flexible ducting is also a good way to reduce the noise from your exhaust fan (by allowing you to move the fan further away). Remember, the more ducting you use, the less air the fan will move. Good venting helps with odor problems, too. Odiferous air can be exhausted from the grow area through an inline ozone generator or a carbon filter.
Buy a fan that will replace the volume (cubic feet) of air in your grow room air in about 5 to 8 minutes or less. The stale air is immediately replaced by fresh air drawn from around the doors or windows. To calculate the room size multiply width by height to get the total cubic feet of your room. Here’s an example: a 10x10x8-foot room is equal to 800 cubic feet. A vent fan should exchange the air within 5 minutes, so for an 800 cubic foot room you’ll need a fan capable of moving 160 cubic feet per minute.
TEMPERATURE and HUMIDITY CONTROL

Growing plants produces humidity. Hot lights produce heat. You will need to control these factors. The easiest method of climate control is to install at least one exhaust vent fan on a timer. Purchase a fan that will replace the volume (cubic feet) of air in your grow area in at least 2.5 minutes. (The shorter the time, the better. It is best to replace all the air in less than 1 minute.) The stale air is replaced by fresh air drawn from another area or a window. Keep in mind that humid air is heavier and more difficult to move; the BIGGER the fan the BETTER.

To calculate the room size multiply length by width by height to get the total cubic feet of your room. Here’s an example: a 10’x 10’ x 8’ room is equal to 800 cubic feet. A vent fan should exchange the air within five minutes, so for an 800 cubic foot room you’ll need at minimum a fan capable of moving 160 cubic feet per minute (but we would suggest a 465 cfm for reasons explained above). The timer will regularly turn the vent fan on and exhaust hot and humid air. While this will help considerably it is still a very rough method of control.

At Hydro Spot, we prefer a more precise form of control and therefore we use vent fans powered by automated environmental controllers. For humidity we use the HUM-1 which keeps the total humidity level within a set parameter through the use of a vent fan. If heat is your main concern, we suggest using a vent fan coupled together with a either a TMP-DNe from CAP or a Sentinel UTC-1. Air Cooling your lights is another possible solution. There are a variety of air
cool reflectors available with 6 or 8” flanges. We prefer the either the Sun-Tube, Radiant, or Daystar.

To dial in both your temperature & humidity control, we suggest Sentinel’s fully digital and precise EVC-2 or CAP’s budget AIR-3. These unique controllers keep both the humidity and temperature within a set parameter through the use of a vent fan. It can also be coupled with a CO2 generator to create a dynamic combination. With this combination if either temperature or humidity get too high, the CO2 generator turns off and the vent fan turns on, until the appropriate environmental levels are returned. Then the CO2 generator turns back on and the vent fan goes off.
CO2 ENRICHMENT

The process of photosynthesis relies on a trinity of elements – water, light and carbon dioxide. Plant metabolism is regulated primarily by the availability of these three essential requirements. If any of these elements are at levels below what the plant needs, the plant will only be able to perform at that level and no greater.
Enriching a grow room with CO2 allows your plant to use excess water and energy stored in their leaves, resulting in dramatically increased growth. Think about this: the average outdoor CO2 level is 300 to 600 parts per million (ppm). But plants can use much more than that. Here’s the wonder of growing indoors – a grow room can be enriched to a level of 1000-2000 ppm. That’s 3 to 6 times the amount of CO2 encountered outdoors. The result? Plants grow faster, fuller and have more zest for life. When using elevated levels of CO2, plant growth rates can increase by as much as 100 to 200%. Even to an already “dialed in” room a 30% increase is to be expected!
In the presence of carbon dioxide, plants prefer warmer temperatures. Heat helps their respiration system increase their metabolism to accommodate the extra CO2. Plants use CO2 to form new sugars, which in turn form plant matter. The byproduct is pure oxygen. Faster respiration levels mean humidity levels increase. Most gardens are generally dry, so the added moisture is welcome. However, gardens using CO2 produce excess moisture and are consequently susceptible to rot and its nasty pal, fungus. Some form of humidity control (vent fans and in large gardens, dehumidifiers) should be employed to keep humidity at an optimum level.
Using Bottled CO2

The most common way of enriching a grow area with CO2 is by using an Injection System like the Reg-1 from CAP. This system runs off of CO2 gas (from a tank, much like a soda dispenser) & is a good choice for a small room. The drawbacks to this kind of enrichment system is the need to consistently change CO2 tanks (although we do offer a dual switch over valve which allows for the use of two tanks) and the fact that it can often take a long time to enrich a room. The largest room this should be used with is 10’ x 15’ (and that’s pushing it).

A CO2 Injection Valve consists of a pressure gauge (monitors how much gas is in the tank), a flow meter (monitors the amount of gas being released) and a solenoid valve (turns flow of gas on and off). Some method of controlling the valve is employed,a timer or a CO2controller. Plastic tubing with holes drilled in it is placed around the ceiling of the room or an oscillating fan to disperse the CO2. CO2, being heavier than air, cascades down onto the garden.
CO2 Generators

Most CO2 Generators create CO2 as a byproduct of burning propane or natural gas. They are built to run off of liquid propane tanks or a natural gas line. The natural gas option is preferable to most growers, as it eliminates the need to constantly refill tanks. Most buildings have a natural gas line, although you may need to have it extended to reach your grow area. We do not suggest you do this on your own. Get help from a professional!

We sell Sentinel and CAP CO2 Generators in which a pilot (controlled by an electronic ignition) is used to ignite the gas when the generator is turned on. A thermocouple is used to monitor the pilot flame. If the pilot flame is lost, a safety valve will close so that unburned fuel will not be released into the enclosure. Generators come in different sizes and you want one which is optimum for your room size – one capable of enriching your room in 5 – 10 minutes.The CAP Generators have expandable burners. The Sentinel Generators have a toggle switch allowing you to select how many burners you want to apply for your given application. (Comes complete with ten burners.)

CO2 generators do create heat, and depending on the size of generator you choose, you may be adding a considerable amount of heat to your grow room. This combined with grow lights can create a very warm room indeed. The good news is that heat is a necessary catalyst for plants to use the added CO2 and that they prefer warmer temps than they do without CO2 enrichment. Most plants prefer temps of 86 – 90 degrees with CO2 enrichment. If your room doesn’t heat up this warm you may need to bring in a heater (this can be the case for greenhouses). More often the room will get too hot and the use of an air conditioner will employed.
CO2 CONTROL

When enriching a room with CO2, the idea is to produce just enough to be effective, but not so much that preciousCO2 is wasted. This simplest way to handle this is to use a timer. If you go this route, we suggest using a timer that is capable of running very precise, timed intervals such as an irrigation timer. Even better is to use a timer that is made for CO2 enrichment such as the Cycle Timer like the ART-DNe from CAP (Affordable Day /Night Cycle Timing down to 5 second intervals), or the Precision Digital Timer from Sentinel – DRT-1 (Allows digital timing down to the second).Both employ a photocell allowing for Day / Night Use or for Both. CO2 is not needed for Night use.

Professional growers will want to take advantage of automated CO2 control equipment that controls venting actions as well as CO2, and quickly pays for itself by providing a method of accurately controlling CO2 producing equipment.
It is difficult to maintain optimum CO2 levels in a grow area employing an air intake and/or exhaust. For this reason, it is important that the room be a ‘closed’ system. Oxygen tends to push additional CO2 out of a room, and since oxygen is created by plants, it is only necessary to vent in order to lower temperature and humidity levels within the space. On the back of this page, we include more information about air flow and venting with CO2.

One of the biggest problems new growers encounter when using CO2 is that they over-enrich the room. When CO2 levels approach 2000 ppm, most plants will die. High levels of CO2 are also toxic to humans and pets.
CO2 ENRICHMENT, TEMPERATURE and HUMIDITY

CO2 enriched rooms can get extremely wet. This increase in relative humidity is due to the fact that the plants’ metabolic processes are occurring at a more extreme rate and water is flowing up through the roots and out of the leaves quickly. Most plants do not thrive in an overly humid environment, and when the level of humidity gets too high it needs to be removed with a vent fan or a dehumidifier. The most common problem for growers is finding the balance between exhausting moist air, enriching a room and keeping the temperature at the right level. If this is done incorrectly, CO2 will be exhausted with the air and plants will not get the benefit of the CO2 enrichment. There are many solutions to this conundrum and here are two of them:

If you are using a CO2 emitter system, and are on a budget we suggest using two timers. It is very affordable, and easy to use. Timers will turn CO2 enrichment on and off at predetermined intervals, based on basic information you provide to our CO2 calculator (Room dimensions, desired ppm, size of emitter in CFH) It does all the calculations for you and creates a CO2 on/off schedule. Once you couple this with a 5-10 minute per hour Vent-Fan Exhaust schedule you will be up and running. Remeber to not turn your CO2 on at night time becuase Plants cannot utilize any CO2.

For larger situations when a CO2 generator is employed, heat and humidity are even more of an issue. In this growing situation, we highly recommend the grower invest in the CO2 Monitor & Controller Package from either Sentinel or CAP. Both are affordable and do the job well. Sentinel makes the CPPM-1 (employs FUZZY LOGIC for more accurate CO2 control) which monitors and controls CO2 levels accurately within the Grow enviornment and allows for a Vent Fan to be hooked up for High Temp override control. (If temps get to HIGH then CO2 is turned OFF and room is exhausted.) CAP makes two CO2 Monitor/Controls – The ppm2a (employs FUZZY LOGIC for more accurate CO2 control) and ppm-3 (Cheapest Digital CO2 Controller on the market today.) CAP and Sentinel also make Enviornmental Controllers (working in conjunction with their Monitor and Control units) which keeps the Enviornment (Temp / Humidity) within the accepted levels. CAP has their AIR – 3 and Sentinel has either their EVC-2 or EVC-1. The CO2 Monitor samples the atmosphere and transmits the values to the Controller which then operates its CO2 outlet (and correspondingly the CO2 generator) according to setpoints. If the sampled level of CO2 is lower than the setpoint, the CO2 generator will turn on. The generator will stay on until the controller is informed by the monitor that the CO2 level has reached the appropriate point. The AIR-3/EVC-1/EVC-2 interrupts the CO2 loop if either the temperature or humidity rise above their designated points on the AIR-3/EVC1/EVC-2. For example, if the humidity is set at 60% RH and the humidity in the room rises to 63% RH, the AIR-3/EVC-1/EVC-2 will turn the CO2 off and turn the vent fan on. The vent fan will stay on until the room reaches the desired humidity level. At that point the vent fan turns off and the CO2 turns back on. If the temperature or humidity go up during dark periods, the vent fans will still function, although CO2 will not. The CHHC-4 from Sentinel employes Fuzzy Logic Co2 Control with the addition of having Humidity and Temp Control. It is like having a EVC-2 and a CPPM-1 all rolled into one. Sa-weet!

In rooms with more than two lights, it is difficult to use CO2 without an air conditioner. HID lights are mighty heat generators, so having more than two will invariably cause problems. A CO2 generator (not a tank) will also add excess heat. We recommend using an air conditioner in these situations. Yes, it is possible to avoid using an air conditioner, but it’s tricky. You must use a carefully designed system using a CO2 controller and air cooled lights to avoid wasting precious CO2. We think it’s easier to whip out your trusty Window mount or “Split Unit” Air Conditioner. (Please note: Portable “In Room” AC units do NOT work for CO2 – They blow ALL CO2 out of the back end exhaust port.)
TIMERS and OTHER ELECTRICAL EQUIPMENT

Indoor Grow rooms and greenhouses rely quite heavily on the accurate timing of equipment. You can use a simple mechanical timer to set the time your lights will be on or off, but for other types of timing, you will want something more specialized.
Industrial timers

Industrial timers are durable and offer features that regular timers do not. Cycle timers are geared for irrigation or CO2 control. Time is broken into duration and frequency, allowing the you to have extremely precise interval times. Another industrial -grade timer we offer is the 24-hour Dual Timer, which is capable of handling up to two 600 watt lights or one 1000 watt light with accompanying pump or vent fan. The beauty of these timers is the flexibility they provide. These industrial timers encourage you to be innovative creating your gardening space.
RELAYS

Relays are used with environmental controllers to allow transfer of power to large equipment requiring high voltage or amperage service. The heavy amp load goes through the relay and not through the controller. Relays are integral in transferring high amperage power loads.
ALL-IN-ONE CONTROLLERS

All of these controllers are capable of controlling both temperature and humidity and include some form of CO2 control. (some use a cycle timer, where others use a CO2 monitor.) They all include a a cycle timer and an auxiliary timer. You will find that some of these controllers have nutrient and pH controlling capabilities as well.
Ozone

So, what is ozone exactly? Well, it’s nature’s way of cleaning the air. You’ve no doubt smelled the results after a heavy thunderstorm — it’s that fresh “just rained” smell.

Ozone is oxygen with an extra oxygen molecule attached. A very strong oxidant, it’s highly reactive with organic molecules, such as mold spores, amoebae, mildew, viruses, bacterium and a variety of pathogenic and saprophytic germs. It also reacts with chemical fumes, smoke, and many organic gases. Ozone rids the environment of these organisms by oxidizing them. Basically, it breaks down their cell walls and totally destroys them, leaving only harmless waste. Even that extra atom of oxygen is destroyed, so there’s nothing left…no odor….no extra atom, only the clean, fresh smell of pure oxygen.

Ozone occurs naturally in the environment. Here’s how it works: Oxygen released from plants and sea plankton during photosynthesis floats up into the atmosphere where the sun’s ultraviolet radiation creates ozone by binding a third oxygen atom to normal oxygen’s two. Ozone is also formed during thunder and lightening storms. A fun fact: natural ozone in the atmosphere blocks harmful UV rays that cause skin cancer.

When electrical charges pass through oxygen, stable pairs of oxygen (O2) molecules are separated. They regroup as ozone (O3). As long as the sun’s shinning, ozone is produced constantly in the upper atmosphere. Since it’s heavier than air, it begins to fall towards the earth. As it falls, it combines with any pollutant it contacts, cleaning the air. If ozone contacts water vapor as it falls, it forms hydrogen peroxide, a component of rainwater, and the reason why rainwater causes plants to grow better than irrigation.

Ozone has been heavily researched; at correct levels it’s been shown to provide healthier environments for both plants and people. Plants have been shown to grow faster in the presence of ozone. For humans, ozone is a powerful professional cleaning tool with hundreds of uses. The hydroponics and greenhouse industry rely on ozone generators to reduce pollen, mold, viruses, bacteria, air pollution and odors.

Take note: it’s important to be careful when using ozone. Because one oxygen molecule is robbed from O2 to create O3, the area is starved of breathable air. For this reason, ozone is corrosive. It can cause breathing problems and destroy plant tissues. Fortunately, ozone is self-policing, and gives off an obnoxious, chemical-like smell well before reaching dangerous levels. The smell of ozone should be subtle, a sweet, clean, pleasant smell. Unfortunately, Ozone has a short life span — about 20 minutes. After that time, it quickly breaks down and dissipates. Be sure to follow the directions that come with your ozone generator and use a test strip to check the levels in your living areas.
Ionization

Processes such as sunlight, lightning, ocean waves and waterfalls generate negative ions that collide with airborne particles, causing them to clump together and fall to the ground– cleaning the air in the process. Ionization eliminates odors, molds, mildew and pollen. It also takes care of collecting dust, chemicals, smoke, gasses and other indoor buildup. According to a recent U.S. Department of Agriculture study, ionizing a room leads to 52% less dust in the air, 95% less bacteria and 40% fewer airborne viruses. Bottom line: negative ions are not only good for your allergies, but your plants will grow faster too.

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