I am going into themode of conseving water so I put a system to direct all the rain water coming from my house gutters to go toa water tank. I have a water pump and I pump the water throught a garden hose to water my trees and vegetable garden. I thought I will get some and spplement it with tap water. To my surprise the water I collect is enough for watering all my plants. I am excited that I am saving the environemental resources. I was bragging about it but one friend told me the rain water might not be safe because it collects germs from the air. I am not sure of what he is saying but to be honest it got me worried. Any opinions on that point.