They come in all sizes, holding from 8 up to 256 plants. They keep light out, offer easy hookups for your grow lights, are waterproof, and provide an exhaust point. Many are sold with lights, exhaust system, and hydroponic system included, making them great for beginners.


See http://howtogrowmarijuana.com/grow-box for a review of grow boxes.
Check out http://howtogrowmarijuana.com/grow-tent for a review of grow tents.
 If you are going to devote an entire room to your crop, you'll want to clear it out. Marijuana plants need a warm, humid environment, so to prevent the growth of mold or pests, you'll want to remove all chairs, curtains, carpets, clothes, and other surfaces that could host mold.You'll need an electrical outlet for your grow lights, as well as easy access to water.
Marijuana grows best between 72 and 77 degrees. Try to choose a room where it is easy to maintain this temperature. Too many windows can make a room too hot, while a basement might require continual heating.
A tile or concrete floor will make for easier cleanup of spilled soil or water.
 Your plants need total darkness in their dark period. Otherwise, they may become stressed and become a hermaphrodite – i.e. grow male flowers that contain no THC and thus reduce your yield. Cover the windows and seal any light leaks with opaque reflective tape., The more light your plants get, the better they will grow. Reflected light from your walls and ceiling can greatly speed up grow time. To make your walls reflective, consider using:Mylar – Aluminized mylar is expensive, but it reflects up to 97% of the light that hits it. Hang it flat against the wall and keep it clean.
Flat white paint – It's cheap, easy to clean, and reflects up to 85% of the light that hits it.
Emergency blankets – You can buy them at camping stores. They only reflect 70% of light, but they're inexpensive and good for small spaces like cabinets or closets.
Aluminum foil – Don't use it! It reflects light poorly, is hard to keep flat, and creates a fire hazard.
 To grow, your plants will need light provided by bulbs that provide a full spectrum of light (unlike normal household bulbs). You have several choices, but broadly speaking, high pressure sodium (HPS) or metal halide (ML) lights will cost less to set-up but more to run, while LED lights will cost you more up front, but save money in the long-run.CFL – Compact fluorescent lights may be used for starts and seedlings, but generally do not produce enough light for the vegetation or flowering phase.
HPS – High pressure sodium lights produce lots of light in the orange spectrum, making them best to use to induce flowering. A good rule of thumb when deciding how many lights to get is that you will need 50w per square foot of growing area.
ML – Metal halide lights produce a lot of light in the blue spectrum, making them ideal for use during the plant's vegetation phase, as they will keep your plant short and bushy. Again, you will need about 50w per square foot.
LED – Full spectrum LED lights are much more energy efficient and do not get hot, so you can mount them closer to your plants and won't need fans to remove heat. You can also use one set of lights for both the vegetation and flowering phase. Follow the recommendations of the manufacturer for how many lights you'll need for your growing footprint.
 You'll need a hood that directs and focuses light on your crop. While LED lights can plug directly into the wall, the hoods that hold HPS and ML bulbs cannot, so you'll also need a ballast for these bulbs, which converts the electricity from yoru wall into a current appropriate for the lights.


HPS and ML bulbs – They are very hot, so consider getting a cooled hood that allows for a ventilation hook up that draws heat away. For a quick guide to how far from your plants they should be, see http://www.growweedeasy.com/hps-grow-lights-setup.
LED – These lights usually come with a built-in fan for cooling.
 If you plant auto-flowering seeds, you won't need to worry about turning the lights on and off. Otherwise, you'll need to turn the lights off twelve hours a day to initiate flowering. An electrical timer will do this for you in case you forget or are away from your plants., You need to keep air circulating in your grow room or grow tent in order to draw heat away from your crop, to ensure the plants get enough CO2, to control humidity, and to neutralize the odor of the plants. Without a ventilation system, you'll have smaller yields and risk losing your plants to diseases brought on by excessive heat and humidity.Oscillating fan – Use an oscillating fan to circulate air so as to avoid hot spots and to create a breeze that will improve growth by helping with transpiration.
Carbon filter – Attaching a carbon filter to your exhaust fan will remove odors that might aggravate your neighbors.
Exhaust fan – You'll want a fan with a high enough CFM rating (cubic feet exhausted per minute) to replace all the air in your grow room or tent every 1-3 minutes.

Determine the cubic area of your space (length x width x height).
Take into account efficiency. If the exhaust travels a straight, short path, multiply your area by 2. If the path is long or twisting, multiply by 3.
Pick a fan with a CFM higher than the number you calculated, particularly if you are going to attach a filter.


Air intake – You'll need a way for new air to enter your tent or room as the old air is blown out. A simple hole (in the tent or a door or window) will do, so long as it is 3-4 times bigger than the exhaust hole. If the intake hole is smaller, you'll want to use an intake fan to avoid putting to much stress on the exhaust fan.
 Your plants will grow best in certain temperature, humidity, and pH ranges. Installing a thermometer, humidity meter, and pH meter in your system will help you perfect the growing environment.
 You can use tap water for your plants, but you'll want to make sure its pH is between 5.8 and 7.0, and it doesn't carry too many minerals.


Letting water sit for 24 hours will help bring its pH closer to 7.
Raise water's pH by adding lime, wood ash, or a pre-mixed solution (available at most garden centers).Lower water's pH by adding sulfur, phosphoric acid, or a pH-lowering solution.If you live in a hard water area (meaning your tap water has a high mineral content), you will want to filter your water. Consult the water hardness map at http://www.qualitywatertreatment.com/city_water_guide.htm.
Use a grow tent or grow box if you don't want to devote an entire room to your crop.
Pick the room you will use and clear it out.
Block out all light.
Cover the walls and ceiling with reflective material.
Choose the grow light you will use.
Install your lights.
Consider purchasing an electrical timer.
Set up your ventilation system.
Set up your meters.
Make sure your water is the right pH and not too hard.
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