Val

Hi, I am new to Feng Shui. My knowledge so far is only from a Lillian Too book, so I'm very pleased to have found your forum. I am in the process of applying the Compass School/Pa Kua/Eight Life Aspirations to each room of my house. I would be very grateful if you could answer a couple of points that are not clear to me. 1. Poison Arrows: when it states that a protruding corner in a room, or the corner of a large piece of furniture is a poison arrow, is it only when it has a sharp edge (i.e. a 90% angle)? Is it still a poison arrow if the edge is rounded slightly? 2. Crystals: I have read that crystals represent the earth element, and also suggestions to hang them in a window, but, is it okay to use them in any sector irregardless of the Productive/Destructive cycle of the five elements? And if crystals are hung in a window, what do they achieve? I look forward to your reply. Thanks, Val