I am going to study abroad soon, so my boyfriend's family will look after my betta in his 5 gal tank while I am gone. We will move the tank to their house. The question is about the source of water to use.... they do not drink the well water out where they live because it has a lot of mineral content. Also because, when asked, a city water official shrugged and said "It's probably safe"... not exactly comforting! However I am wondering about their filtered drinking water that they get from Aqua Falls - I don't think it's distilled, but I worry if it's been filtered too much to where there wouldn't be enough oxygen or minerals for the fish. Please share your experiences with water sources, it would be helpful.