Coarse bubble diffusers are most commonly used in secondary treatment applications, where substances such as sediment and carbonate can build up quickly. The growth of these materials can be detrimental to fine bubble diffusers, which have smaller openings that plug more easily. Engineers and operators often choose coarse bubble diffuser solutions for applications that require more space and larger openings. These uses may include aerobic digesters, grit chambers, sludge holding tanks and equalization basins.