Marijuana Grow Guide - Transplanting
There will be little or no shock if you are quick and tender in your handling of the plants. Make sure you only need to transplant twice, or better yet, once if possible, through the entire growth cycle. Transplanting slows you down. It takes time, it is tricky, it is hard work, and threatens the plants. Start in as large a container as possible, square is best. 16 ounce plastic cups work OK, and 2 litter soda bottles cut down may be big enough for the first harvest when growing hydroponically. One-gallon plastic milk or water containers (squarish) will work too.
Or start seeds and rooted cuttings in 16oz plastic cups. It is better to have less seedlings than it is to have many seedlings that need constant transplanting. These larger cups take only a little more space, and allow you to transplant only one time before harvesting the first crop. Transplant into a gallon water jugs (cut down to 3/4 gallon) before forcing flower growth. To regenerate this plant after harvesting, transplant it into a larger pot after it goes into vegetative growth once again, 5 gallon paint buckets work pretty well if you can spare the space, and a 2-3 gallon container would make this plant is 2nd harvest better than the first, given enough vegetative regrowth first.
One more tip:
A Russian study showed that seedlings with at least 4" of soil to grow the tap root were more likely to go female. The source I am quoting says "This may be why some farmers get female/male ratios as great as 80%/20%."