MarijuanaHow To Grow Hydroponic Marijuana
This is an attempt to explain how to grow hydroponic marijuana, for personal use, indoors. It is meant for people who live in areas where growing marijuana is legal or tolerated for medical or other reasons. Do not use this information to break the law. When you grow hydroponic marijuana yourself, you know the crop will be potent (if you started with good seeds) and clean. That is something you can't always count on when buying from someone else. This is especially important if you are growing for medical reasons. Using hydroponics to grow plants is fairly simple once you understand how it works. Anyone who wants to learn to grow hydroponic marijuana will succeed in time, but some beginners will quit after one or two failed crops. When you know how to grow your own, you will not have to pay ridiculous prices for top grade marijuana and you will never run out. You will also not have to deal with people that you otherwise might not ever consider doing business with. You can use a hydroponic garden to grow just about any kind of plant, not just marijuana. The experience you gain growing hydroponic marijuana can be applied to any other hydroponic crop you decide to grow in the future. A hydroponic garden will require daily monitoring and maintenance to make sure everything is working properly. If you are away from the grow area for more than a day or two at a time, growing hydroponic marijuana might not be possible. How it works: A seed that has been germinated and sprouted a root or a plant cutting (clone) is placed in a hydroponic garden and supplied with nutrients (food) and light. After this, the plant develops a root system and leaves. Plants are given about 16-18 hours of light a day during this (the seedling) stage of growth. After the plant has put down a solid root system and grown some leaves, it enters the next stage of the marijuana plant life cycle. This is called the growth or vegetative phase. During this phase the light source is on 18 to 24 hours a day. When growing hydroponic marijuana indoors the seedling/vegetative stage usually lasts 4 to 8 weeks. The next stage is called flowering. When growing indoors, the flowering stage is started by cutting the light down to 12 hours on and 12 hours off per 24 hour period. With most marijuana strains, the flowering stage lasts about 8 to 12 weeks. Almost all THC (the primary cannabinoid that causes marijuana intoxication) is produced during the flowering stage. At the end of flowering, marijuana plants are harvested, then allowed to air dry. Total time from germinating to harvest is about 4 months. This can be shortened to 3 months or less by using two growing areas, one for the first stages of life and another strictly for flowering. Where To Grow Hydroponic MarijuanaThis guide is about growing hydroponic marijuana indoors, so the growing will be done indoors. Where to grow your marijuana depends on what space you have available. An attic, closet or similar space will do, but a room dedicated to growing is preferred. Things to consider include: The biggest problem most new growers face is maintaining the proper temperature for the plants. A room with an exhaust fan on the ceiling is a good choice, if it is available. The exhaust fan on the ceiling will help keep the temperature cool, and if needed, you can upgrade to a stronger fan to remove a larger volume of hot air (created by the grow lights). A section of a basement also makes a very good area to set up a grow room. An attic will work but heat can be a real problem unless very well ventilated. All grow rooms require fresh air (from another room or outdoors) or supplemental carbon dioxide to replace carbon dioxide that the plants breathe when the grow light(s) are on. After you have decided where you are going to grow, you have to clean the area and keep it clean. That means scrubbing walls, cleaning equipment, washing floors, etc. Carpets should be removed, if possible. Everything in the growing area should be cleaned then sterilized with something like lysol, bleach, or some other germ killer to minimized the marijuana plants from being harmed by germs, bacteria, molds, etc. If you are going to grow in an area where the floor may be damaged by water spills (there will be some), the area where the hydroponic system is placed should have some kind of floor covering that will protect it. A thick drop cloth (the plastic sheets painters use to protect items from paint damage) will do a good job. Once clean, you can paint the walls and ceiling with white paint to reflect light or use black/white visqueen plastic (white side towards the plants so light is reflected). Commercial reflectors like mylar are sometimes used for this purpose because they are more efficient. Do not use mirrors because they absorb light. gloss white paint is about 70% to 75% reflective Indica And Sativa Before you can start to grow, you will need marijuana seeds or clones. There are two species of cannabis that are grown to produce marijuana, they are Cannabis indica and Cannabis sativa. Even though there are dozens, if not hundreds of marijuana strains, most strains used to grow marijuana are mainly indica, mainly sativa, or an indica/sativa mix. All things considered, mainly indica plants are by far the best plant for hydroponic beginners growing indoors. They are easier to grow, don't get as tall, and produce a larger harvest than sativa plants. The main drawback is indica plants have lower THC levels than sativa plants, this makes them a bit less potent. As a grower gains experience they may try growing an indica/sativa mix. When very experienced, an indoor hydroponic grower may try a mainly sativa strain. But for the first few crops, stick with indica or indica/sativa plants. Hydroponic System For Growing MarijuanaNow you have a basic idea of how things work, let's get into more detail. If you are going to be growing hydroponic marijuana and have chosen a suitable location, you will need a hydroponic system, also called a hydroponic garden. There are different types of hydroponic systems available to marijuana growers. If you would like to know more about hydroponics and the different types of hydroponic systems, there is an article at wikipedia. The most common systems for growing marijuana are: The method you choose should meet your budget and be able to fit in your growing area. NFT and aeroponic systems can be a bit harder to maintain. The number of plants your garden can sustain and the area your garden covers will determine how much light you need. Read the section in this guide about lighting before deciding on a hydroponic system. A hydroponic system is made to grow plants without soil. Plant nutrients (food) are mixed with water and supplied to the plants roots by a pump or other method. This delivering of nutrients means that the plant doesn't have to expend as much energy making roots in search of the nutrients it requires. Energy not used looking for food is used to make the plant develop its leaves and flowers faster than they would if grown in soil. When supplied with sufficient light, it's normal for marijuana plants in hydroponic garden to grow as much as 1 to 2 inches or more (per day) during the vegetative growth phase. Because no soil is used, most hydroponic systems require something for the plants roots to anchor themselves to. This is usually referred to as the growing media or growing medium. Rockwool is probably the most well known hydroponic media. For a personal indoor hydroponic marijuana garden, plants should be grown at least eight to sixteen inches apart. Some strains are bushy and they will require more space but produce a larger yield than a slender strain. Unless you plan on growing small plants, the roots require a fairly large area to grow in. The opening for each plants roots should be about three inches (or larger). This will accommodate a marijuana plant that will produce a half ounce of marijuana or more. Smaller plants can be grown with a smaller space for roots. The hydroponic garden pictured here is an NFT type garden but other types of hydroponics systems can be found with similar dimensions. It's 24 inches off the floor and covers a 48 inch by 48 inch area. A reservoir (shown in black in the picture) placed below the area where the plants grow (shown in white in the picture) is filled with water and nutrients. A pump moves this nutrient solution from the reservoir and supplies it to the roots of the plants growing above. Openings for the plants root system are about 3 inches by 3 inches, ideal for 3 inch rockwool cubes. Capacity is 23 plants spaced about 9 inches apart. Plants grown 9 inches apart will only be able to branch 4.5 inches away from the main stem before competing for light with adjoining plants. This might be ok for slender plants, but with marijuana plants that will produce 1/2 to 1 ounce each at harvest time, you would only be able to grow a maximum of 6-8 indica plants (9-12 sativa plants) in a garden with these dimensions. Some of the plant openings wouldn't be occupied. The extra room would allow plants to branch further and produce a larger crop. If you grew 6-8 high yield (but not very potent) indica plants in a hydroponic garden with these dimensions and used a 400 watt lighting system, the expected total yield would be about 8 ounces (1/2 pound) at harvest time. Under the same conditions a more potent indica or an indica/sativa strain would allow you to produce less than that, but the increase in quality might be worth it if quantity is not the prime concern. If you grew 9-12 sativa plants in a hydroponic garden with these dimensions and used a 400 watt lighting system, the expected total yield would be about 4-6 ounces at harvest time. A high yield indica strain grown in a properly maintained hydroponic garden of this size (supplied with 400 watts of light) would provide enough marijuana to allow you to consume about 2 ounces a month without ever having to buy marijuana again. A more potent mainly sativa strain might only produce enough marijuana to allow you to consume a bit over 1 ounce of marijuana per month. The above numbers are based on having 1 grow area and harvesting once every 4 months. Production can be increased by using 2 grow areas and harvesting more often. Do not expect to harvest the amounts stated above when you first start growing. For the first few crops be happy if you are able to raise a plant without killing it. Once you understand how things work you can focus on getting the maximum yield. Reflecting all available light on the plants is essential for getting the most out of your indoor garden. Even experienced growers that have years of experience raising successful crops sometimes overlook this and purchase higher wattage lighting to increase production. Lighting For Growing Hydroponic MarijuanaChoosing a hydroponic system will necessitate the consideration of the right grow light for your needs. The most common lighting types for growing hydroponic marijuana are fluorescent, light emitting diode (led), metal halide (mh), high pressure sodium (hps). Fluorescent lighting is usually run during seedling stage and can be run during the vegetative stage. It is not recommended as the primary source of light for flowering because of the limited amount of light energy produced. Light emitting diodes are usually run during seedling stage and can be run during the vegetative stage. They are not recommended as the primary source of light for flowering because of the limited amount of light energy produced. Metal halide lighting is usually run during vegetative and flowering stages. It is not recommended for seedlings because of the large amount of light energy produced. High pressure sodium lighting is usually run during vegetative and flowering stages. It is not recommended for seedlings because of the large amount of light energy produced.  The sun emits light energy that spans from the red to the blue end of the light spectrum. Grow lights produce light at specific frequencies that cause them to look a certain color to human eyes. Marijuana growers most often put 'cool white' bulbs in fluorescent light fixtures. A majority of people describe the color of the light as white, with a slight blue tint to it. Light emitting diode grow lights are usually blue, red, orange, white, or a combination of these colors. Unless you have a specific purpose for getting a single color, it is best to get an led grow light that is made up of a combination of different color lights. Standard metal halide light looks similar to the 'cool white' fluorescent light found in schools, offices, stores, and other high traffic areas. High pressure sodium light looks similar to the 'warm' incandescent lights found in homes, but has a deeper orange-red color. The street lamps in some cities are hps lights. Fluorescent and led grow lights are good for the seedling/vegetative stages of growth (or as supplemental light when flowering) but at the present time (december 2010), they will not produce as potent or big of a harvest as mh or hps grow lights during flowering. It will also take more time for the plant to mature. If led technology improves and prices come down, led grow lights might become the best choice of grow light in the future. But if you are serious about growing marijuana now, metal halide or high pressure sodium are the only grow lights to consider, at least for flowering. Beware of people that claim fluorescent or led grow lights will preform as good as mh or hps lights, they are probably somehow making money by promoting a product. Ask any experienced marijuana grower if fluorescent or reasonably priced led grow lights can compare with mh or hps for flowering marijuana plants. What light should you get? In a perfect world sunlight would be the only source of light needed, but it's not commonly available in sufficient quantity indoors. The next best thing is a grow light. During the first few weeks of life when the plant is in the seedling stage, mild fluorescent or led light should be provided. Too much light can permanently damage or kill the plant at this stage, so metal halide or high pressure sodium are not recommended. 48 inch fluorescent shop lights with 2 bulbs are inexpensive and will provide more than enough light for seedlings. Get 'cool white' bulbs rated at 30-60 watts each. Different size shop lights are available, but the 48 inch size are the most common, and often the cheapest. You can run mh and hps lights during the seedling stage but they must be kept much further from the plants than they would during vegetative and flowering stages. Keep in mind that running a 400 watt mh or hps light during the seedling stage when you could get by with under 100 watts of fluorescent or led light, is not cost effective. During the vegetative stage, plants can be grown under fluorescent, light emitting diode, metal halide, or high pressure sodium lighting. Fluorescent or led light will do the job, but mh or hps light will make the plants grow more quickly. If you plan on supplying mh or hps light during the vegetative stage and have a choice, mh is recommended over hps. During the flowering stage, plants require as much light as possible, so metal halide and/or high pressure sodium light is needed. The amount of light a mh bulb emits is usually lesser than an hps bulb of the same wattage. If all brands of mh and hps grow lights that are 400 watts were compared, the bulbs that put out the maximum amount of light energy will be hps. There are some brands of mh bulbs that will put out more light than some economy brands of hps bulbs, but in general hps bulbs are usually more efficient (convert more electrical energy into light energy). For this reason, most marijuana growers choose hps for flowering. Don't worry if you use mh for flowering, the yield might be slightly smaller but it will be just as potent. Both mh and hps lights could be run during both the vegetative and flowering stages of growth. But, this is not always possible because the cost of two light fixtures will be more that of a single fixture. Two light systems will also take up more space and might produce more heat than a single unit. You can run:
The list below gives an approximate idea of the area covered and how many marijuana plants can be grown with a certain wattage light system in a dark room. Any sunlight you can give the plants will increase the number of plants you can grow, and will help the plants produce a larger harvest. The number of plants in the list below is an approximate maximum number of plants you can grow with various wattage mh or hps grow light systems. It is not exact, but it should give you an idea of the area a grow light can cover. If flowering a plant is initiated when it's 8-12 inches tall, you can expect a medium sized plant (about 3-5 feet in height) that will produce an ounce of marijuana or more at harvest time.
In order for the heat produced by a light system not to harm the plant, a 250 watt light system should be started 18 to 30 inches above the tops of the plants, a 400 watt light system should be started 3 to 4 feet above the tops of the plants, A 600 watt light system should be started 4 to 5 feet above the tops of the plants, a 1000 watt light system should be started 5 to 6 feet above the tops of the plants. The light should be lowered a few inches everyday until the light is as close as it can be without harming the plant. You will have to figure out the optimal distance yourself because it will vary depending on bulb efficiency, quality of reflector, and other things. Whatever your light source, replace bulbs after 6 to 12 months of use. If the light is on 24 hours a day replace it after 6 months. If the light is on 18 hours a day replace it after 9 months. If the light is on 12 hours a day replace it after 12 months. You can run the same light bulb till it burns out, but it will become less efficient (produce less light and a smaller harvest) the longer it's run. One note about replacement bulbs, they can be divided into three categories: vertical (base up), horizontal, universal. Vertical bulbs have to be installed in vertical position fixtures with the base up. Horizontal bulbs have to be installed in horizontal position fixtures. Universal bulbs can be used in a horizontal or vertical position. If you can't locate a vertical or horizontal bulb for your particular lighting system, make sure you get a universal bulb. It will work in either type of fixture. The standard ceiling is 8 feet (96 inches) from the floor, most hydroponic systems are on a platform that is 18 to 30 inches off the floor and the plant itself will probably be at least 18 to 36 inches tall when fully grown. In most cases if your ceiling isn't more than 8 feet (96 inches) from the floor, the largest light system you should get is 400-600 watts. 400-600 watt systems are used by a majority of marijuana growers who are growing for personal consumption. If you need more light, get 250, 400, or 600 watt lights rather than 1000 watt lights. Experienced growers know how to limit the height of marijuana plants so they don't get too close to the heat produce by a bulb, but the first time grower should use a 1000 watt light systems only in areas with ceiling heights of 10 feet (120 inches) or more. Seeds Or Clones To Grow Hydroponic MarijuanaNow that you understand hydroponic systems and grow lights, it's time to decide on seeds or clones. Most people start from seeds but someone who is currently growing a crop will be able to provide you with clones from female plants. Clones are simply cuttings taken from a growing plant. After a cutting is taken from the mother plant, it will develop into an adult plant, if provided with reasonable growing conditions. Clones will be exact copies of the plant they are taken from. Make sure to get seeds or clones from someone who can tell you the origin of the strain (indica or sativa), expected yield size, expected flowering time, and if the seed is meant to be grown indoors or outdoors. Marijuana seeds can be hard to obtain. If possible, try to obtain them from a source that is close and reliable. If you have to order them and have them mailed to you, try to do so from a seller that lives in the same country as you. As a last resort you can order from another country, but that means your shipment will have to go through some kind of customs search when entering the country where you live. Not only could your seeds be confiscated, it could cause legal trouble for you. A mainly indica strain is probably the best choice for an indoor gardener to start with (growing with either hydroponics or soil). In general, they are easier to grow indoors, produce a large yield, don't grow tall, and the high is good. After you grow hydroponic marijuana from seed, you should learn to clone your plants. Once you know how to clone marijuana, you will not have to buy seeds to start a new crop again. To ensure a supply of seeds for future propagation, you can produce your own by selectively pollinating a single flower on a female plant (not the entire plant) with pollen from a male plant. When the plant is harvested, the single flower that was pollinated will contain dozens of seeds. Set up your hydroponic garden and check your light before you germinate the seeds or get clones. Add plain water with no nutrient solution and start your hydroponic system. Make sure everything works and there are no leaks. Let it run for a day or more before putting the plants in. Tap water must be aged for 3 days or longer prior to being used in a hydroponic garden. So if you added water right from the tap, wait for 3 days before putting the plants in. When you are sure that your garden functions properly, you will need to germinate your seeds. If you germinated the seed directly onto your growing medium, you can put it in the garden when you know the seed has sprouted a root that is about a quarter of an inch long. If you germinated the seed on paper towel, wait till after the seeds have germinated and the root is about a quarter of an inch long. When you see that it is, place the seed (root down) in the hydroponic system growing medium according to the manufacturers instructions. Wash your hands prior to touching the seeds for any reason, and be very gentle. Do not touch the root itself, it is very sensitive and may be permanently damaged if mis-handled. You don't have to, but some growers find tweezers the best way to work with seeds. If you have obtained clones, set up your hydroponic garden. When you are sure it functions properly, put the clones in the hydroponic system according to the manufacturers instructions. After the seeds or clones are put into the garden, allow them to remain in darkness for 8 to 10 hours before turning on the light. This is to allow for recovery from the shock of transplanting, and is more important for clones than seeds. It is best not to start the seedlings or clones off with hps or mh light. A better idea is to begin with fluorescent or led light turned on for 16-18 hours a day until the plants reach the vegetative stage. Place the fluorescent or led fixtures about 3 to 10 inches above the plants. 4 to 6 inches is good, but you might have to raise the light a bit higher so all the plants get some light. Depending on the size of your setup, you might need more than one light fixture. After about 1 to 2 weeks in the right growing conditions, the plants will establish a solid root system and start to produce leaves. This is when the plant goes from the seedling stage to the vegetative stage. Growing Hydroponic MarijuanaAt this point you can either keep supplying fluorescent or led light (plants grow slower), or you can introduce metal halide or high pressure sodium light (plants grow quicker). If you are switching from fluorescent or led lighting to mh or hps, remove the fluorescent or led lighting then install and adjust the height of your metal halide or high pressure sodium fixture. When you first start the metal halide or high pressure sodium light, the distance from the top of the plants to the light source should be started at the following height and lowered daily until you find an optimal distance:
For the first week have the light on 18 hours a day and off 6 hours a day. After the first week you can add an hour of light a day until the light is on 19 to 24 hours a day. The longer the light is on the faster the plants will grow, but plants do best with at least 2 hours of sleep per 24 hour period. You want the plants to be as close to the light as possible without being burned. If the parts of the plants closest to the light dry out, raise the height of the light source, they are too close. If the plants are too far from the light they will stretch and be tall but not produce much bud. That is a waste of space and light energy. Start high and lower the light a few inches daily until you think the height is right. Don't forget to raise the light as the plants grow. Plants can grow several inches in a single day. As the plant grows, some leaves will die and should be removed from the plant by cutting them rather than pulling them off by hand. You may also want to prune your plant. The plant is allowed to grow in the vegetative stage until it is big enough to provide a worthwhile amount of marijuana when harvested. When growing hydroponic marijuana indoors, the seedling/vegetative stage usually lasts 4 to 8 weeks. You can let the vegetative stage last several months with no negative effects on the plant. But the vegetative phase can be ended (and the flowering stage began) as soon as the plants are large enough. Hydroponic Marijuana FloweringFlowering is the phase of marijuana growth that produces the most THC (the primary chemical that produces intoxication). You could start flowering when the plants are a minimum of about six inches tall and have at least four sets of leaves, but the amount of marijuana produced by a plant of this size might be small. Starting the flowering process when the plants are no more than about ten to twelve inches tall is recommended when using a 400 watt light source (usually after 4 to 8 weeks of vegetative growth). Any taller and the light can't reach some of the lower branches. If you are using a 250 watt light try flowering when the plants are about eight inches tall. Marijuana plants grown under 600-1000 watt systems can be a bit taller before flowering, but most growers will flower at twelve inches or less even with a 1000 watt light. Higher wattage bulbs produce enough light to penetrate to the lower branches. The higher the wattage, the taller your plants can be. When the plant is large enough to force into flowering, turn off the light and allow the plant to remain in complete darkness for 24 to 36 hours (you don't have to do this but I've found the plants flower faster by doing so for 36 hours). To initiate flowering, adjust the light timer to turn the light on for 10-14 hours a day. Most people start a light cycle of 12 hours a day on 12 hours a day off. If the plant got 18-24 hours of light per day prior to flowering, it will flower when the light is on for between 10-14 hours a day. Less than 12 hours light a day and the plants will be ready to harvest sooner but they will produce a smaller yield. More than 12 hours of light a day and the plants will produce a lager yield but it will take longer for them to mature and harvest. When you grow hydroponic marijuana indoors the height of the plant will continue to increase for about four to eight weeks after flowering has been started. Strains with sativa heritage will usually take longer than indica strains for the height to stop increasing. After a few weeks of flowering, the height of the plant will slowly stop increasing and most of the female plant energy will be used for flower production, unless pollinated when some energy will be used to produce seeds. During flowering, the dark period must be perfectly dark. No room light, sun light, or any other light should reach the plant in the hours of darkness that the plant must get everyday. The strongest light that should reach the plant during the dark period of flowering would equal that of moonlight and only for short periods. Stronger light than this will delay flowering, and if it continues there is a chance that the plant will not flower, but stay in the vegetative phase. This is more important in the fist 4 weeks of flowering. When the plants have started to flower for over a month, small amounts of light for short periods of time during the dark period are not as harmful. You will know the plants are flowering when you see what look like little sacks appearing on the male plants and white hairs (pistils) developing at bud sites of female plants. They should become visible about two weeks (slightly longer for sativa plants) after the flowering light cycle was started. The white hairs turn color as the plant ages. They will eventually be the red/brown hairs that you see on marijuana that you have probably smoked in the past or are smoking now. How To Tell Male From Female Marijuana PlantsSinsemilla marijuana is a term for female plants that have not produced seeds. Not producing seeds allows the plant to devote more energy producing THC and other chemicals that consumers require. An ancient tradition for cannabis growers, sinsemilla is the result of removing male plants from the grow environment before they have a chance to fertilize the females. People who grow hydroponic marijuana indoors always grow sinsemilla. Growing sinsemilla outdoors is harder. Outdoors, a single male plant can fertilize females within an area of a few hundred feet, or even further depending on the wind. Indoors, a single male plant will fertilize all females plants in the grow room. If you have started from clones you can skip this part as the clones you obtained were female but if you have grown from seed, you will have to separate the male plants from the female plants before the male plants flower and produce pollen (unless you wish to produce seeds). There is approximately a 50% chance a seed will be either male or female. Assuming all the seeds are of the same strain, the male plants will almost always mature before the females. The male plant will have small oval pollen sacks that the female lacks. Once you see these sacks, remove the male plants from your garden. In contrast, white hairs (pistils) will begin to develop at bud sites of female plants. Harvesting And Curing Hydroponic MarijuanaAfter about 8 to 12 weeks of flowering it will be time to harvest. It is very important to harvest at the right time. The optimal time to harvest marijuana plants is just after THC production has reached its maximum, and is starting to slow down. A rough guide as to when to harvest is to wait until 50%-80% of the white pistils (hairs) have turned dark (usually brown or red). But a better method of determining when to harvest is to wait until the resin glands of certain trichomes on the plant have matured. Trichomes on marijuana plants that develop a resin gland at the top are a rich source of THC, and monitoring them will allow you to best judge when the plants are ready for harvesting. A better description of harvesting directions can be located here. Right after the plants have been harvested, they should be manicured (leaves removed from the buds), then dried and cured. Marijuana is not at peak potency just after harvest, it can also be harsh and bad tasting. Drying will let a majority of the water in the plant evaporate quickly and curing will finish the drying process. After the plants are cut down, some of the THC is in a non-psychoactive acidic form. Besides improving the taste, drying and curing marijuana will convert the non-psychoactive acidic compounds into psychoactive THC. A better description of drying and curing directions can be located here. If your marijuana is going to be stored for any amount of time, it should be put in an air tight container and be stored somewhere that is dark, dry, and cool. Remember that light, air, and heat are the things to avoid. They will degrade THC and make marijuana less potent. last update: october 2011 Related Books Jorge Cervantes' Ultimate Grow DVD Jorge Cervantes' Ultimate Grow DVD 2 Grow Great Marijuana It will explain the steps involved from start to finish (with text and images). Includes information on where to grow, type of hydroponic system to use, selecting a seed strain, lighting, fans, nutrients, security, clones, vegetative growth, flowering, harvesting, stress, pests, and more. Recommended for beginners only, this will show you everything you need to raise a hydroponic marijuana crop. Marijuana Grower's Handbook At the present time this is the best choice if you were only going to get a single book about growing marijuana. Bear in mind this is not a grow guide with step by step instructions. It looks at most issues that a grower will face at some time and is recommended for beginners and experienced growers. |