yes i love doing the cold air thing, i also hit my roots with ice water when i flush you got about 30-40 days to go so try to hit the cold more when you are about 10 days to finish, you should get some really great color fades as well as some purples. should be a great show, and no you do loss leaf when you put on the cold, its the plants way of saying hey i am done with this leaf, beside your growing the plant for the bud not the leaves