Need help with sick plant?...Look here

For newbies and growers alike, this was given to me a while ago, and the more i search the forums the more i see people with sick plants that have no idea what is wrong with them. I hope this will help save a few of them.
International Cannagraphic Magazine Forums - The Complete guide to Sick Plants,pH, and Pest troubles!

so my plant is 2 and a half months old and in the flowering stage but the bottom leaves are drooping? the top half of the plant is still fine just the bottom ones? i dont kno why it is doing this any help would be great