Hydroponics is the growth of plants without the use of soil. A fertilizer solution is used instead to provide the plants the nutrients they need to survive. Although it sounds like an expensive process, growing food hydroponically can be quite economic. Recycling old 2-liter bottles as a hydroponic pot helps the environment by reducing landfill use, one bottle at a time. Growing hydroponically can save on space, and nutrient concentrate costs less than potting soil.
Remove the label from your 2-liter bottle and cut the top off, just below the shoulder (the rounded portion leading up to the spout).
Poke a hole into the cap using a nail. Make the hole about 1/4 inch large.
Mix the nutrient solution as instructed on the side of the solution bottle. Check the pH of the nutrient solution using a pH testing strip. The pH should be between 7.2 and 7.6, but may differ according to the plant you are attempting to raise. Add more water if the solution is too strong, or more nutrient concentrate if the solution is too weak.
Fill the bottom portion of the bottle with the nutrient solution.
Cut a strip of cotton, wet it and pull it partially through the bottle cap. Tighten the bottle cap onto the top portion of the two liter bottle and place the top portion of the bottle, top down, inside the bottle bottom. The cotton strip should touch the nutrient solution in the bottom portion of the bottle.
Fill the top portion of the bottle with peatlite. Fill the bottle slowly, winding the cotton strip through the solution in a corkscrew fashion.
Put a plant or seed into the soil, depending on what you wish to grow.