Some impurities in water are exceptionally fine, such that if they were to be left to settle under gravity the tank would need to be unfeasibly large. Bringing them together to form larger particles that would settle more readily can often be difficult, as they carry electrical charges that need to be overcome. This process can also be made difficult if the amount of solids to be removed is low. Coagulation/Flocculation is the process of creating the correct conditions so these particulates can be brought together to form flocs of solids in coagulated water. These flocs will readily settle and produce good quality treated water.