i just had same problem 3 days ago.5 plants all around a week old and almost 5" high. spindly stalks bout as thick as a toothpick. lots of people told me to bury the stalk deeper even if u bury it up to an inch from ur bottom leaves, i did so as well as moving my lights(2 x 55watt cfl) around 2/3" away and my probs were solved. ive changed from 24hr to 18/6 as well. i think it slows the stretching down and lets the plant spread a liitle. if ur gaunna support ur stalk dont use metal. use the outside of a ballpoint pen its plastic and wont leech shit into ur soil, or a thick toothpick. the ones u get a macdonalds on the corncobs are good and thick.