Don’t overfill the bowl. You should be able to clear it in one or two hits. 550 sounds closer to what you’re looking for. Go up by ten each bowl until you get the hits you’re looking for. A little black on top is fine but once you get the popcorn taste you’re fully extracted. If you get black on top but the bottom still has some green then your airflow is off. Fluffy, coarser grind is preferred. The idea is for the hot fluid to flow over and around the plant matter freely.