Her is the start. Troubleshooting When you first start a hydroponic system, you may face early failures. There are several reasons for failure. Light - Probably the most common reason for failure of a system is inadequate light. Plants are normally grown in open sunlight.
Indoor light is usually quite different from outside sunlight.
Indoor artificial lights have different components of colors of light. Some may be deficient in red light, others in blue. Also, most indoor lighting is not as intense as outdoor light. Plants that do not have enough light fail to thrive. One sign which shows up in sunflowers and other long stemmed plants is a elongation of the stem, showing a struggle for light.