Yup thats usually what i do eliminate the bottom stuff thats gonna be weak so the energy can be put toward the tops. But if i dont cut the bottom branches off they most defiantly go to hashLower buds don't get enough light to grow. Many growers just eliminate the lower branches early on. You "can" harvest the tops and keep growing the lower stuff, but in the long run it might not be worth it. Better to just harvest it all and get a new grow going.