Just bought my house (120 years old). It is supposed to have "newer" plumbing". It's been vacant since the rehab was completed in Novemeber of '07. It has awesome water pressure. Just ran the bath tub for the first time tonight while cleaning and noticed that after the tub was full, the water had a green tint and some fine granular-like sediment had come up too. I drained the tub and filled it with only cold water and it was very clear. I filled it again with only hot water and it still had a green tint, but not as bad this time.

Does anyone know what this could be? The water heater was replaced in 2003, it's a GE, but it already has rust on the outside of the tank...

Thanks!