To slab or NFT when seedlings are 2 inch. None, however watch N carefully. Requires full sun.
Dill grows slowly during short days.
Dill is easy to grow and well accepted in this market. It is less likely to bolt at high temperature than coriander. You may harvest by cutting the tops at the crown and allowing to re-grow or pull up the roots. Consider leaving the stonewool on to improve shelf life. Nutrient Film Technique.