Tannins Water Test Kit for Well or City Water - Add-on To Test Kit Only (West)THIS IS AN ADD ON Product ONLY You must have a test kit in your cart to add this product to the test parameters. (Note: The Problem Check test kit includes this test and it does not need to be added on) Tests your well or city water for the presence of Tannins. Tannins can occur naturally with the breakdown of organic matter in or around a water source. They can cause aesthetic problems like a yellowish color and can stain laundry or plumbing