Hydroponics is the practice of growing plants in an inert medium; you grow your plants without soil. The plants are anchored in clay pellets, gravel or other neutral medium. The plants' roots are housed within a hydroponics system; that system will have a reservoir for water. You add hydroponics nutrients to the water. This is the equivalent of fertilizing soil. You do need to refresh the nutrients on a regular basis, as the plants' continual uptake will deplete the solution.
Nutrients added to water within the hydroponics system allow the plants' roots to access the required elements directly from the water. The nutrients imbue the water with the necessary elements for plant growth and setting fruit. Setting fruit is when the plant flowers and subsequently produces seed or fruit.
Hydroponics nutrients are made up of macronutrients and micronutrients. Nitrogen, phosphorous and potassium are the three major elements found in both soil fertilizer and nutrients for hydroponics gardening. Calcium, magnesium, sulfur and silicon are also macronutrients found in nutrient mixes.
Micronutrients are trace elements. Minute amounts of such elements as copper, zinc, iron and sodium, along with a host of others are combined with the micronutrients.
Hydroponics nutrient mixes can be dry or liquid. Dry nutrients are granular in form and must be dissolved in water so the plants can access the nutrients. Liquid nutrients are added to the water supply and stirred to mix.
Plants have different nutritional needs at different times throughout their life cycles. As your plants grow, you may need to use different types of nutrients. General nutrient formulas will include all the essential elements in proportions that will address the general growth needs of most plants.
Different formulas are available for specific, targeted needs, however. You can find products designed to promote root growth that work well for younger plants that need to establish a strong root system first. Bloom formulas promote flowering and fruit setting. More specialized formulas can be used for growing vegetables, fruits, flowering plants and herbs.
The plants in your hydroponics garden absorb only those nutrients they require and in the necessary amounts to maintain health. Within two to four weeks, the water in the reservoir of the hydroponics system will have been depleted of a good many elements. You will need to empty the reservoir and replenish with fresh water and nutrients. This will ensure a steady supply of nutrients for the plants throughout their life cycles.