An apparatus and method for controlling a water characteristic of a body of water by controlling the cyclic release of a water characteristic material into the body of water with or without the system being responsive to a level of the water characteristic in the body of water. The field of said reorientation layer has a component parallel to the liquid crystal layer, said component being crucial for the reorientation. The supporting component supports the main body. Examples of image document streams include video, PowerPoint slides, and NoteLook pages. At least another one of the printing stations has a rotatable ink-receiving first cylinder for receiving ink in a nip with the associated ink applicator, and which cylinder has a periphery for printing letters andor numbers each of a size which is a fraction of the size of the areas which receive ink from the projecting outermost layer of the multi-layered flexible body. According to the invention, the deviation indicator with infrared imagery comprises an infrared pulsed laser and the device for controlling and processing infrared images also processes the laser pulse echoes.