Bacteria in water can take many forms and the best way to know the type present is to have your water professionally tested by a certified water testing laboratory. A common symptom of bacteria in water is a slime build-up in the toilet tank. Some types of bacteria like E-Coli can cause gastro-intestinal problems. A lot of times people are surprised to find that their water contains bacteria since there are not always obvious symptoms., After identifying the problem through professional testing, the process of eliminating the organisms varies by considering effective process, cost effectiveness and personal choice. In most cases the choice is Ultra-violet disinfection. An ultra-violet light system kills bacteria as the water passes through the light chamber without adding any chemicals to the water. Look for our Coupon and SAVE $5.