All plants require certain elements to survive and grow. In addition to sunlight and moisture, plants require nutrients, oxygen and structural support. Plants growing in nature obtain these elements from the soil encasing their root systems.
Hydroponics eliminates the need for soil. This method of growing plants without soil requires a support system, oxygenation system and the addition of supplemental nutrients in a liquid solution. A homemade hydro system works well for growing a few small houseplants or herbs.
Find a sunny location for your hydroponic plant. Choose an area near a window with a southern or western exposure for best results. Most plants, including hydro plants, require adequate amounts of bright sunlight. Do not place your hydroponic system in an area subject to frequent temperature fluctuations or cold air drafts.
Select a large, deep casserole dish. Set the dish upside-down over your Styrofoam sheet. Use a pen to draw an outline of the upturned dish on the Styrofoam. Cut along the drawn line on your Styrofoam with a sharp knife. Check the placement by setting your Styrofoam sheet into your casserole dish. Trim the edges to allow the Styrofoam to sit just inside the rim of your dish.
Place three or four Styrofoam cups evenly over your piece of cut Styrofoam sheet. Use these as patterns, drawing around the cups on the Styrofoam. Cut out these circles with your knife. Cut a small slit through the bottom of each of your cups. Press the tips of few seeds into the slits in your cups. Press the bottoms of the cups into the holes in your piece of Styrofoam so the bottoms of the cups are level with the bottom surface of the Styrofoam piece.
Set your casserole dish in the sunny location. Fill your casserole dish with non-chlorinated water. Add the hydroponic solution according to the package instructions. (Purchase this solution from gardening centers or nurseries.) Place the Styrofoam sheet with the inserted cups over the surface of the water. The Styrofoam should touch the water and float on top.
Replenish the solution as it evaporates. Keep an eye on the solution level and add more when it drops about 1/2 inch from the original level. In arid climates, you may need to add additional solution every few days to keep the level near the rim of your dish. Depending on the type of seeds planted, you should notice your hydro plants sprouting within one to two weeks.
Prune away any uneven growth or wilted leaves and stems from your hydro plants. Keep these small plants healthy by removing faded blossoms from hydro houseplants and harvesting hydro herbs as they mature.