I always wait until two weeks into flowering to transplant into the final pot. For indica doms, this allows a finish before the buffers in the soil start to fade, and allows for adequate rootspace. For sativa dominates, it gives 'em half a chance, lol. Use proper care, and don't break anything.

Keep in mind the ingredients in the potting soil will be fresh and active. Miracle Grow type of pre-ferted soils aren't recommended for this final transplant, but if it's all you've got...:thumbsup: