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How to grow marijuana hydroponically


Growing marijuana hydroponically

You can realistically use almost any portion of your house, garage or shed to grow indoor marijuana plants. Just remember to keep the most basic of plant needs in mind when setting up your growing location. If you are not sure what your marijuana plant requires, then just imagine looking at your garden in the middle of a sunny, calm day during the summer. This is typically the ideal setup when growing marijuana plants, so you must strive to duplicate this environment when growing marijuana plants. You will need each of the conditions listed under the following headings: Light Source, Proper Temperature, Low Humidity and Atmosphere.

Light source

All growing locations need the proper light before anything else. Depending on where you grow your marijuana plants, you will either be able to use sunlight or you will have to provide the light to your marijuana plants. When trying to duplicate the light of a summer's day, it will take a lot of light positioning to have the right environment. We are going to help you get the right amounts of light by assuming your growing location is pitch black. Windows or skylights are typically not enough light to affect marijuana plant growth either direction. When you are providing the light to your cannabis plants, you must also take into account the dark hours outside. We recommend you use a light-less growing location and set up all of the lighting yourself, leaving nothing to chance. If you use a greenhouse, the darker portions of the year would be the only time additional lighting would be necessary. Ideal growing locations will offer white walls to reflect the light back at the plants from all directions and plenty of light to help the plants grow quickly.

Proper temperature

You must be able to keep a constant temperature within a growing location for marijuana plants because temperatures that are either too high or too low can kill off your marijuana plants. The ideal range for most marijuana plants is between 68 and 83°F (20 and 28°C), trying to stay as close to the middle as possible. You can use the heat emitted from your lights to help your grow room stay the proper temperature, as long as you can vent off the excess if the room gets too hot. You can easily set up a fan with a thermostat to have this process automated for you. Once your lights are turned off, it is normal to experience a gradual decline in temperature. During the coldest portions of the year, you should expect temperatures to dip significantly below your optimal growth range. This drop has the potentially to negatively effect the productivity and shape of your final marijuana plant. If you can keep a constant temperature during both day and night cycles, that is ideal. Many growers install a propane heater of some sort and attach it to a thermostat, keeping the room between 68 and 86°F (20 and 30°C).

You can then set up your thermostat to work in connection with your lights and the fan to always keep the optimal growth temperature going. You will also notice that your propane heater will significantly increase the carbon dioxide that your marijuana plants receive, helping your cannabis plants grow exponentially larger. The one piece of equipment that you will buy that you cannot live without will end up being your minimum-maximum thermometer. You should be checking it daily and always making sure it is calibrated properly. You will want to keep track of what your lowest and highest temperatures were during each day so that you can continually adjust everything within your grow room so you have the ideal growing environment. If you notice your temperatures are going too high, you will need to adjust the fan and settings for when it turns on. If your temperatures happen to dip too low, then take a look at the settings on your propane heater. Everything within an indoor growing location screams about needing the proper control to duplicate the growing environment these plants require. You can also use a thermo-hygrometer within your growing location to monitor highs, lows, temperature and humidity. This will realistically be your only opportunity to recreate within your home what Mother Nature has provided outside.

Low humidity

Humidity is still quite important to serious marijuana growers. If it is not monitored, the humidity can get high enough to damage your room and your crop of marijuana plants. You mainly want to avoid getting grey mold, or Botrytis. The higher the humidity, the more this type of mold will thrive and spread. You never want to forget to monitor the humidity within your growing location, and you should always install a hygrometer to keep tabs on humidity levels. You ideally want this to be mounted up on your wall near your thermometer, allowing you to have constant humidity reading. You want to keep your humidity around your marijuana plants to just over 50%. High above this level will damage your plants, so your fan should be used until the humidity levels drop. Keeping excess water out of your growing location can help keep your humidity levels under control. Just make sure you clean up any spills of nutrient solution or water as soon as they occur, and always keep the tank holding your nutrient solution covered. This will keep evaporation to a minimum, and help to keep humidity levels low. Just keep your growing location constantly dry!


The air within your growing location needs to also be considered before starting any marijuana plants. This is also where you are going to run into the biggest debate. All plants need fresh air, that is a given. Marijuana plants, however, also need a constant stream of CO² in order to keep growing. While normal air has approximately 330 parts per million (ppm) CO², this is simply not enough for optimal growth of marijuana plants. They will constantly be starving for more CO² until this need is met, declining overall growth. The grower can continually run a fan to always bring in a new supply of fresh air, to help with the problem slightly, or the grower can add CO² into the growing location. If the grower chooses the fan, more heat is going to be required to avoid cold harming the growth of the marijuana plants. Plus, depending on the weather, leaving something within the home open to gain access to fresh air may not be feasible. Supplementing CO² is typically what serious marijuana plant growers resort to in this circumstance. The grower can either add CO² by using a propane heater or they can regulate the levels with CO² bottles bought from hardware stores.

CO² from bottles

There are many locations that sell CO² because of its many uses. Most places have it on hand to help pressurize a beer keg. Even though you can buy CO² in many different sizes, we would recommend using a medium sized bottle for ease of use. You will not want to try and carry one of the large bottles up a flight or two of stairs-take our word on that! Aluminum cylinders make transporting CO² much lighter. You will also need to purchase a regulator to help control just how much gas comes out at a time and goes into your growing location. There are amateur regulators that anyone can handle or professional-grade regulators for those with CO² experience. These will make injecting CO² into your growing location much more simple.

Generating your own CO²

A Growth Gas Generator is a machine that just creates CO² to help plants grow better. It is meant to be used in a small growing location like a closet or greenhouse. It simply takes propane and burns it, creating all of the CO² your plants could need. Electric solenoids control this machine, so it makes using a timer to control it quite simple. This makes it even easier for a marijuana plant grower to provide all of the CO² the plants can possibly use. You will want your grow room filled with CO² during the hottest and brightest parts of the day, when each plant will be able to use the most. Growers can also use CO² sensors to help stabilize the levels and keep them under control. This machine is recommended to be used in an area that is less than 141 sq. feet (43 sq, m) because its only objective is to produce CO². It really produces no heat when compared to how much CO² it can create.

Each Growth Gas Generator is made up of high-grade stainless steel, and has been crafted to survive many years of use, even in the humidity of a greenhouse type environment. You will not find the same drawbacks with Growth Gas Generators as you would with a heater meant for a greenhouse, because these machines are able to be set to create CO² during the day. Heaters would create the most CO² at night because they only give off CO² as a byproduct of creating the much needed heat. If you are able to maintain CO² levels of 1500 ppm or potentially even more, you will notice humongous changes in the growth of your marijuana plants. If you want to be a serious grower who can produce a yield that past growers could not have imagined, then you will want to give your marijuana plants the ultimate in lighting, hydroponic growing solutions and the amazing benefits that a little extra CO² can provide.

Measuring your CO² levels

Due to recent technological advances, novice marijuana plant growers are now able to measure just how much CO² they have within their growing locations. CO² Analysis kits are available on the market now, so you do not have to guess anymore. CO² can be detected with the use of a pump-action analyzer syringe combined with analyzer tubes. They are set to detect anywhere from 300 to 5,000 ppm. Each kit will come with the full instructions on how to properly use it, and a quick check of your growing location ought to tell you just where your room stands. Serious marijuana growers will consider CO² almost as important as the water to a marijuana plant, so they will take the time to make sure the room is optimally controlled for the benefit it will have on their marijuana crops.

Negative ions

Many growers will also install a negative ion generator within their growing location. These little devices are typically quite inexpensive and cost very little to operate. These machines can refresh the air within your growing location and remove harmful particles, such as bacteria, pollen, cigarette smoke and dust. The ability of these machines to revitalize each particle of air is just amazing, and you will notice these benefits when you see the boost to yields and quality within your marijuana plant. They can also help stop the overwhelming smell of foliage within your home.

Pest control

This topic is far too large for us to cover in depth here, but we can give you a few ideas on how to deal with some of the most common issues most marijuana growers face. This is one of the most highly debated topics among marijuana growers over the years, so we are going to go through this brief description on the assumption that each marijuana grower prefers avoiding all toxic chemical usage whenever they can. The changes in all aspects of marijuana growing have been immense, but these tips have been tested numerous times by experienced marijuana growers so we feel comfortable sharing them with all growers. The change to biological forms of pest control is showing where the future with all plant growing lies. It comforts us to think that within just a few years we will be able to avoid the use of pesticides altogether and grow everything without the worry of contamination of our environment. The simplest way to explain the biological form of pest control is through the use of bugs and other creatures that are good to plants to fight back against the forms of creatures that harm plants. Even though they are little, they work as incredibly effective predators. Here are just two simple examples:

Two spotted mite vs. The spider mite

Even though it is nearly impossible to see spider mites with the naked eye, they can do a ton of damage to a marijuana plant crop. Most growers do not find them until their numbers are incredibly high, plus they can multiply at devastating rates. Under the right circumstances, spider mites can destroy an entire marijuana crop. Growers will first notice tiny dead spots showing up in small clusters on any leaf that has become infested. As the number of spider mites increases, the foliage will also begin to go bronze. The higher the number goes, the easier it will be to see the fine webbing that they leave on the bottom of each infested leaf. These particular mites have always outsmarted other methods of control due to how resistant they are to all poisons in general.

The increase in toxicity has come as the way that most humans have begun to respond to the increase in pests, but the success of these horrid chemicals is on the decline. Plus these chemicals destroy the good creatures that are normally there to help control the number of pests, allowing the pests to grow out of control. Biological forms of pest control would suggest that we use a different type of mite, referred to as the "phytoseiulus-Persimilis". These mites exclusively live on the Two-Spotted mite. When pest numbers are high, predator numbers increase in relation to how much food they have. Once the food supply decreases, the numbers of predators will decrease as well. At that point, there should remain a balance among the levels of pests. If the number of pests happens to be too large for the predator to control, all the grower has to do is change around the environment slightly in favor of what the predator needs instead of the pest. Commercially, these predatory mites are referred to as "Spidex".

White fly

The majority of marijuana growers are familiar with the tiny white flies that cloud around marijuana plants when they are affected. They should be looked at as a major pest, especially when looked at on a commercial level. Chemicals have once again failed to stop these pests, so we must once again turn to biological forms of pest control. A small wasp known as "Encarsia-Formosa" is the whitefly's predator. These minuscule wasps are considered harmless to all other creatures except the white fly. It looks quite a bit like a fruit fly, just on a smaller scale. If not for the white fly, these wasps would not be around because it is white fly larvae, which is used for laying the wasps eggs and feeding the growing Encarsia larvae. Basically all new white flies come out as wasps who can then lay additional eggs on any remaining larvae. These predators are commercially known as "En-Strip".

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