I am finding out this information for a friend who is possibly moving, I think mabe a 100w fluorescant bulb should be fine for a mother, or no?

Does the amount of plants planted really matter, when using around a 600w hps or less? with less plants you'll get more weight on each plant, but with more plants less weight per plant, im sure strains have different attributes and would behave differently. but i always wondered that question