My daughter lives in Philly. The hot water tap in the third floor bathtub discharges water with a distinctive green color. This is the only tap that runs green in the house. The lines are copper. What are some possible causes and solutions?

Has any work been done on the water lines lately? Solder paste will leave a green residue in the pipes but will flush out in time. Do you flush your hot water heater out on a regular basis to remove minerals that have built up inside the tank? Let me show you how. For long life and fewer troubles you should keep your heater clear of mineral build-up by flushing on a regular schedule. Attach a hose to the boiler drain at the bottom of the tank. With the pressure on, open the boiler drain and let it run until the water runs clear. You will see a spurt of red,(rust) followed by white or yellow grains,(lime or calcium carbonate). This shouldn't take more then a few minutes. Do this monthly to keep it clear. Now flush out your hot water lines on ALL fixtures that are affected . Now pull each aerator and clean the screens. Be sure you put them back togather the same way you took them out. Don't forget to flush it out every month. Your heater will thank you for it. Hope this helps, Tom