ice 3x I have done this before and I have had success in doing it..what i used though was a 50 gal drum...(heavy pain in ass, but it worked.). my plant was like around 3.5 feet and I just wanted totry it ..so ..hey it worked but you have to be consistant If ur going to do it. Im sure that just about anythin will work just block out the light, but do it before sunset until after a little bit after sunrise and just remember the solstice is around sept 23 dependent on what area u live in so do it until then an BAM!!!you should have harvest.....grow on...smoke on...peace