Iron bacteria and iron algae are easily identifiable in areas where water has been sitting stagnant for more than a couple of hours. The most convenient place to look is usually the flush box on the back of any toilet. If there is a brownish-orange slime building up on the sides of the tank and/or the top of the water. If this substance is present in the back of your tank, you probably have iron bacteria. For help identifying iron bacteria or iron algae, please see our consultation page to contact a water professional.