Now that we've looked at the different type of hydroponic systems, let's take a look at some of the tools and accessories that work to complement the various systems
The most important part of any hydroponic system is, of course, the nutrient solution used. Hydroponic nutrient solutions are readily available from gardening centers and nurseries and are composed of a blend of such nutrients as nitrogen, potassium, calcium, magnesium and other minerals. Different nutrient solutions are used depending on what type of plants you're trying to grow, what system you're using and what mediums, if any, you're working with.
As we've seen, hydroponics can be done with or without mediums. In cases where a medium is to be used, there are several choices available, each with its own benefits and drawbacks. One of the most popular mediums used in hydroponic gardening is rock wool, due to the fact that it's both affordable and offers easy drainage. Other popular mediums include clay, perlite, vermiculite, sand and gravel. While gravel, clay and sand are both cheap and easily available, they're heavy and don't provide the same level of water circulation as perlite and vermiculite, which are more expensive but also more effective.
Another critical aspect of hydroponics is the use of light. As we discussed earlier, plants require light in order to perform photosynthesis. In areas where natural light is not available or plentiful, High-intensity Discharge (HID) lights are used instead. There are two main types of lights used for gardening, and each provides light over different parts of the spectrum. Metal Halides (MH) offer light from the blue end of the spectrum and are used with young plants and green, leafy vegetables. High Pressure Sodium (HPS) lights are at the opposite end of the spectrum and are used for fruits or flowered plants [source: Green Coast Hydroponics].
Finally, any successful hydroponic system must be monitored so that PH levels are regulated. PH is a measure of hydrogen ion concentration, and gives us a value as to how acidic or alkaline the growth environment is. It must be kept within a certain range, depending on the plant and the medium used. The value can be measured using a PH testing kit, available at any gardening supply center.