Hydroponic gardening is a way of growing plants without the need for soil. Plants receive sustenance from a nutrient solution, formulated specially for soilless gardening. Contrary to popular belief, hydroponic gardening is as simple as regular gardening. Plant growth is easier to control in some cases with a hydroponic garden, as opposed to difficult soil.
The pH of the solution determines how your plants will grow in your system. The pH is measured between the numbers 1 to 14. Most plants are happy with a neutral pH, which is around 7. A pH that is lower, between 1 and 7, marks an acidic solution, while an alkaline solution will have a pH above 7. You can use paper test strips to determine the pH of your nutrient solution. To solve high or low pH, special formulas are available called "pH up" and "pH down," which will raise or lower the pH of the solution respectively. "pH down" contains phosphoric acid, while "pH up" uses potassium hydroxide.
Nutrient solutions are relatively easy to control, although sometimes a solution will loose its effectiveness, discoloring or stunting the growth of a plant. Leaves that are small or light green require more nitrogen, while leaves that are a deep green with yellow in between the veins require more phosphorous. If making your own solution with individual nutrients, add those to the mixture after performing a pH test. When using a premade solution from a garden center, change the entire solution to prevent imbalance.
Grow lights are required when using a hydroponic solution indoors. Most plants, according to the University of Illinois, most plants require around 12 hours of light a day. Grow lights will become hot during this time. Positioning of the grow lights is integral to keep plants from burning or overheating. Easily flammable material should be kept away from grow lights to prevent fire. Grow lights require at least 12 inches of space between the plant and bulb to prevent radiant heat from damaging the foliage, while good circulation from a fan will prevent the buildup of heat.