3 months ago I gave a friend a bonsai I had created out of the maple called Crimson King. I was aware that she was a busy person and may not have the time to devote herself to the bonsai on a daily basis. Thus I rig up a simple automatic watering system for her. It consists mainly of a porous tube or cube if you like, to which is attached a 3 feet of rubber/plastic tube and a tumbler. Initially fill the tube completely with water, then attach the tube making sure the attachment is airtight. Next you insert the cube into the soil of the plant close to its rootball. Now fill the tumbler with water and place the open end of the hose into the tumbler. As the soil dries up, water leaks out through the porous walls of the cube and new water from the tube replaces the water lost. More water is forced into the tube by air pressure until the tumbler becomes dry, so it needs refilling about once in 1 to 2 weeks before becoming too dry. You will observe that the rate of water flow can be controlled by the height of the water level in the tumbler in relation to the position of the cube. If you need to water more, raise the position of the tumbler above the pot and you have gravity working for you. When gravity works against you then the rate of watering is decreased. This set up works like a charm for her and she is beginning to enjoy bonsai without the tedious attention that she would normally have to devote to it.