I've become a big fan of Ed Rosenthal who is one of the best growers around and he's old school. I've come to find that that many of the posts on sites like this elude to some mystic about growing weed. Sure you have got to follow simple horticulture guide lines but really that's it. Growing medium, fertilizer, pH ed water and lots of light. It also helps to know where to find help for sick plants. Keep in mind growing weed has become a big industry. Vendors as well as many on these sites lead you to believe this, that or the other product is necessary to be successful. Just not true. Buy the least expensive 150 watt HPS you can find on the net or at a big box store for about $11.00 up to $23.00. Your plants will never know the difference.