Hello. I have some questions. What is the filtration on this model? For example, the C3 dog and cat is a sealed system and has a filtration of 99.9%, but I cannot find this information on the C1 dog and cat. I know the C1 is not. sealed system, though. Do you have to bring these in to have the brush cleaned? If so, how much is the service fee How often should these be brought in for basic cleaning and servicing?