hi dopey, welcome to the forums...

i could spend the rest of my life typing a response to answer your generic, yet extremely deep question...

or i could be a bitch and say, "go read the faq's, noob!!"...

or i could give you this link and ask that you read all of these pages before asking q's again. seriously, this will make you a guru...

http://www.marijuanahydro.com/mature...anaplants.html

your welcome sweetie, and good luck on your ventures

love, kp