The recommended light cycle varies, but I perfer to use an 18 on 6 off schedule. Some people think that the "rest" that occurs during the off cycle is important to the health of the plant, but that's just hearsay. I've always har good luck with the above schedule. I don't think you should need stakes if you put a fan on your plants. That not only strengthens the stalks and dissipates the heat, but provides a good supply of fresh air. Post some pics when you can so we can see whats going on.