I know that some of you are probably wondering why I would want to take the time to do something like this when it's pretty easy to grow crops outdoors when the weather permits or, better yet, pick up my produce from the grocery store.
Lets take a moment to think about how many months of the year are actually warm enough to grow crops outdoors in central Pennsylvania. Maybe 6 months? The numbers do not look good for plant survival unless, of course, you have a well insulated year-round greenhouse. So... for the average poor college student, home-built hydro systems might look like a fairly reasonable idea. While these systems can be difficult to maintain, it is possible to grow crops year round.
Why not buy decent quality produce from the grocery store and save the hassle? There are several reasons for this; One, the cost of buying vegetables compared to the cost of growing them is very clear. What you will pay for a large yield of a particular vegetable grown in your own garden is time, attention, a little fertilizer here and there, and about $1.99 to offset the cost of seeds. Aside from the cost of buying vegetables from the store, we also have to think about the environmental effects of shipping produce across the world. Now... I know some of you might argue with me about the environmental effects of the automobile. If you don't believe me, ask the communities in Alaska having to move their settlements because their land is falling into the ocean.
Lets not forget about the fact that I can be one of few college students to say "I have a hydroponic garden in my dorm room."
I'm going to move on to the technical side of this experiment of mine. I think it might be appropriate to explain some of the terminology I will be using in this post. The word hydroponics refers to the growing of plants without traditional growing medium (soil) and the supplying of nutrients through a water-based fertilizer solution. Aeroponics refers to having the roots of the plants suspended in the air. Nutrients are supplied to the plant by spraying a fine mist of fertilizer water directly onto the roots periodically. Growing mediums refer to the substance that the plant is rooted in.
I was inspired by the large varieties of systems that Disney's Epcot has on display inside one of their rides. Most of the technology used to supply nutrients to the plants was water based, whether it be a hydroponic flow system or suspended aeroponics. I spent some time after that researching different concepts behind hydroponic gardening and found that it would be fairly simple to create my own system. I found an abundance of forums on homemade hydroponic systems. I found several similar systems (the triple S... it was fate) with a short lists of household objects used to create a fish tank bubbler system. I read through these lists and quickly realized that I would end spending very little money on this system due to the fact that most of the parts were collecting dust in my basement. I went to my house and collected the following items:
- 10 gallon (give or take a few) fish tank
- air pump (most likely came with the fish tank)
- air stone (most likely came with the air pump)
- 1/4 inch thick foam poster board
- aluminum foil (enough to cover the sides of the tank)
- net pots (small mesh gardening pot)
- growing medium (rock wool, small gravel, coarse sand, etc.)
- hydroponic fertilizer (EcoGrow is a good brand)
- 5 gallons of water
- vegetable plants (get the hang of using pre-planted vegetables before playing around with seeds)
- fluorescent light (full spectrum grow lights are best)
Make sure all of the parts are clean! While this may seem like common sense, it is very important for me to cover this. By clean, I mean free of any soap residue, dust, blood, etc. Anything other than clean neutral pH water can have bad effects on the plants.
Measure the opening of the fish tank and cut out a sheet of poster board the size of the fish tank. We're using foam poster board because it will float on the top of the water easily. One thing I've found useful in my testing is to peel the paper off of the poster board and use at least two sheets of the foam. When the paper coating takes on water, it can weigh down the foam. When you have your foam sheet(s) cut out, cut holes in the top large enough to fit the net pots through but small enough to keep them from falling into the water. You want the bottoms of the pots to be submerged. Once the holes are cut, set that aside and get ready to transplant some vegetables.
This part of the process can be stressful. Transplanting small plants can be deadly for the plants if proper care is not taken. The goal here is to get the plant out of one medium and into another with as little root damage as possible. The roots are responsible for the intake of nutrients. If the roots are damaged, the plants cannot absorb nutrients thus killing the plants. If you are trying to transplant from dirt, run cold water over the roots to loosen the dirt. You may have to remove some of the dirt manually. Once the roots are clean, you can put them into your new hydroponic medium. The main purpose of the medium in this system is to give the plant support while it grows. What you want here is to have the water covering as much of the roots as possible without submerging the stem of the plant. Make sure the roots are far enough into the net pot to achieve this. Add just enough of your medium to keep the plant standing while it grows. Once your plants are in the pots, make sure to keep the roots moist while you work on assembling the system.
Next, you will want to carefully pour your fertilizer water into the tank. Make sure that the air stone is close to the middle of the tank to encourage even air distribution in the water. After all, this is what the roots will be breathing while they're submerged, sort of like fish! If you don't have a check valve for the air pump, make sure the pump is above the water level. If the power fails, you don't want water tracking back through the air hose into the pump. That's bad news for the pump.
You'll want to cover the outside of the tank with some lightproof material to prevent the growth of algae in the tank. This can mess up the air stone and the growth of the plants. Most sources I've read suggested using black paper or some sort of fabric, but I've found that using aluminum foil is best because it's reflective and it doesn't get hot in the sun. If you have any better ideas, please try them!
Now you can get your vegetable boat ready to sail (I'm sorry for the unfortunate metaphor.) Take the net pots and put them into the holes in the foam board. Take one last look at your plants and make sure they are in a good position before you put them into the system. Once you're ready, carefully lower the foam raft into the water and make sure it floats. Once everything looks secure, turn on your fluorescent light and position it directly above the tank. Obviously, you can't recreate sunlight. If you have the option, put the tank near a window with plenty of sunlight.
Once the plants are fairly mature, if weather permits, you can put your plants into the ground. What you do with them is completely up to you! You will want to keep an eye on your plants and take note of any changes you notice. You'll want to do some additional research if you notice any color changes or wilting. Any unusual change can be a sign of nutrient deficiency or surplus. Also, you may want to try different things and see how they affect the growth of the plants. Try planting two of the same plant; one in the hydro system and one in potting soil. Be creative with your experiments. Who knows; you might discover something cool!
I am free to take any additional questions you might have. Bear in mind, I am still working on this myself. I have much to learn about this concept. By asking good questions, you challenge me to learn more!