Before we actually get started, there are a few more important considerations. The first is to decide the actual location for your garden. As we just learned, growing hydroponically outdoors is great because the sun is free and there's often plenty of space. But you may not be able to grow outdoors because you are in an apartment building or congested urban area. In this case, you have the option of growing indoors using High Intensity Discharge (HID) lighting. Whichever way you go, if you pay close attention to the guidelines discussed in this publication, you should succeed without difficulty.
If you want to grow indoors, plan on investing in an HID light. (see this book's lighting section for information on what kind of light will work best for your needs). I use a 400 watt metal halide lamp with reflective hood to light nearly four small gardens simultaneously, with excellent results. You may choose to substitute high output fluorescent instead, but you'll get more light output, and certainly more yield, with an HID lamp. In planning your light coverage for your new garden, try to get at least 30-40 watts of light per square foot of garden. I prefer 40 to 50 watts per square foot of garden, because I have found that the extra light makes a big difference. So plan ahead, and decide on your lamp sizes based on the growing area of each garden. If you want to illuminate more than one garden at a time, you can use this simple formula to determine your lighting requirements. Multiply your growing area's width by its length, and the resulting sum by 30 to 50 watts (depending on crop). The final number you get from this calculation is your required lighting wattage. Standard indoor HID grow lights come in 100, 150, 175, 250, 400, 600, 1000 and 1500 Watt sizes. Most high output fluorescents deliver about 10 watts per running foot of bulb. To achieve proper illumination with fluorescent lighting, plan on using an array of 4 bulbs for every foot your garden is wide. For example, if your garden will be 3' x 4' - use four 4' bulbs per foot of width, or twelve 4' bulbs total. This will give you 40 watts per square foot. Perfect! Keep them close to the plants too, no more than 6" to 12" maximum. Also remember, the combination of water and electricity can be hazardous to your health. Follow the safety precautions on product packaging and inserts. Keep your lights and ballasts away from moisture. And use a fan to circulate air throughout your garden.
When growing outdoors, your garden plan should include a way to protect the reservoir from heat and direct sunlight. Remember that you want to maintain your nutrient solution temperatures between 68 and 75 degrees F. If you are using a system that uses a pump to re-circulate the nutrient solution, consider burying the reservoir to take advantage of cool and consistent soil temperatures. You can also use aluminum foil to reflect sunlight to help prevent the reservoir from getting too hot. In hot climates, you can create a cooling loop and then bury it in the soil between the reservoir and the injector manifold to further dissipate heat. Note. this may require you to use a larger pump to overcome the extra resistance that the additional tubing will introduce. Keep any electrical equipment protected from rain, and use only equipment that is stated to be suitable for outdoor use by the manufacturer. I also strongly recommend that you hire a licensed electrician to install the proper wiring and outlets to power your outdoor garden. Here are some additional factors to keep in mind when building your system. Hydroponic systems subject parts to a slightly acidic solution that can cause degradation of some materials. Avoid using metallic parts, especially for those that will come into contact with the nutrient solution. When choosing a reservoir, look for those made from resins approved by the FDA for use in constant contact with food. Rubbermaid Roughtotes are made from such plastics. Parts availability may require substituting an item here and there, so you may need to be crafty from time to time. Clean all parts before use with a 10% solution of bleach to remove mold release compounds and any contaminants they may have picked up while being stored. Avoid using automotive hoses and tubing, choosing only those made for hydroponics and aquarium use. And if you can't find what you are looking for at your local retailer or garden center, visit www.futuregarden.com/hydroponics
The next few chapters detail the construction of eight different types of hydroponic and aeroponic systems. The following is a quick overview of each with important considerations.
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