im using rainwater that hits my roof and thought i may start using a cheapish uv sterilser to clean water of bacteria. any thoughts? its almost impossible to ascertain if they are effective through internet reviews. what i do at present is to boil the water and let it cool before i put it in the tank, but i can only get it to 80 degrees without faffing around too much with seperate pots. thought someone might know if either were effective at all at preventing bacteria in the tank.