The fan blowing on the plants will help strenghten the stems. The reason my cups are only half full is that if/when they stretch, I just add more soil to bury them to their necks.
Here's a pic of the underside of my light panel before I added the splitters and the lights. The sockets were $1.39 each, the extension cord was .99, the plastic chain I used to hang it was $6.99 and the wire nuts and screws were just laying around.
although i don't think ill use it i still love it solstice. I just took all the clear cups off and the raised the fan a bit and its not completely knocking over the plants.
That's a matter of great dispute. All I can tell you is that it works for me. New roots will grow from the part of the long stem that gets buried. That much I know for fact.
When they need it. In those little cups half full of soil, maybe once a day. I check them all at lunch time and after dinner. They get an ounce of water at a time. An ounce goes a long way in those little cups. When they dry out, they get another ounce. I weigh the cups to determine when to water. After the first transplant, I use instinct coupled with a water meter. More on the instinct side, though.
That looks a lot better to me. I might have to search around a bit but back when I was looking to add light to my grow I found a place that was selling just a ballast, socket, and bulb combo for $85... But 400 watt!! There's no reflector but you can just hang it vertically like you were talking about.
You said that you were growing in "garden soil". Exactly what kind would that be? I could be wrong, but I see hints of time-release nutes in that soil.