Safer® Hydro FAQ: What's Best - Seeds Or Clones?
Seeds offer you many varieties or strains with distinct traits to choose from and they are the natural way annual plants start themselves, so they tend to be vigorous and to grow extensive root systems.
There are many sources for seeds and you can even grow those you've saved yourself from previous crops. Clones, or cuttings from existing plants, offer uniformity -- that is, the clones will have the exact same traits, such as size, color, and flavor, as the plant from which they were cut. Clones also give you a head start, since they already have leaves and form roots quickly.
To get clones, you need to have existing plants yourself or know someone who will share cuttings with you.