The Bagua mirror is one of the most easily recognizable of the Feng Shui household items. The concept of the bagua is to deflect or contain negative energy to preserve harmony within the home or office. It is an 8-sided wooden or plaque with a convex, flat or concave mirror set into the middle. The bagua, which means 8 areas is marked with the 8 trigrams of the I-Ching, one symbol per side, and is thought to help manage and protect the energies of a home or business.
Poison arrows come from certain combinations of structures and angles that create a point directing energy into a space. They structures can be anything from a sharp corner to the T-junction of a road, to lamp posts and telephone poles. While given the name “poison,” the arrow of chi is not thought to always be off bad energy, but it is always considered to be too strong a flow of energy that will disrupt the balance of the chi in a home. An advanced Feng Shui practitioner can read the poison arrows surrounding a location and place appropriate Feng Shui cure to interrupt, absorb or neutralize the arrows. The mirror in the bagua was designed to capture or deflect such outside energies so they cannot enter the building.
To hang a bagua correctly, it is mounted outside the home with the Qian at the top and the Kun at the bottom. A bagua is never hung indoors. There are different meanings assigned to the mirror shapes as well. A bagua with a concave mirror is thought to absorb negative energy, while convex baguas deflect it and is considered the most powerful. Flat mirrors are considered gentle, as they are believed to diffuse a direct energy stream. Whenever possible (when the poison arrow is not considered very strong), opt for a concave bagua because it does not deflect negative chi and harm your neighbors.