| EM, I have grown one zinnia plant from seed to seed indoors under fluorescent lights, but I used a sterile growing medium (Premier Pro-Mix BX) instead of hydroponics, and I used overdriven fluorescent fixtures for extra brilliance. I used 32-watt cool white T8 tubes. The lights were on a timer, and I had it set up for a 16-hour day and an 8-hour "night". I used small electric fans for air circulation. Actually I had several zinnias in pots under lights, but I transplanted all but one unique "breeder" to the garden in early June. I did use hydroponic-like urea-free soluble nutrient formulas, including calcium nitrate, but I didn't use our well water to water with. I used melted snow and rain water, to avoid salts build-up. I repotted the zinnias to semi-large 8-inch pots. This winter I probably will go to larger pots, because the zinnias depleted the water in the 8-inch pots nearly daily. I hope to have a lean-to greenhouse in service by this winter, so I can grow more plants "inside". It is very handy to cross pollinate the plants when they are in separate pots and you don't have to fight off the bees. Incidentally, I refer to one of my hybrid crosses that I started indoors as "echinacea flowered" zinnias. I am hoping to expand on this strain next year with improved flower forms and a wide color range, including two and three tones.
 MM | 
