Don't worry about inner ear fluid. It's supposed to be there. It's called endolymph and perilymph. See http://www.cochlea.eu/en/cochlea/cochlear-fluids - you'd be in bad shape if you didn't have inner ear fluid.
What you probably refer to is middle ear fluid. That's less welcome there. The middle ear is the part behind the ear drum, that sometimes gets filled with fluid/pus. It affects the mobility of the drum/ossicles and can therefore show up as conductive losses. It can give an impression of ear fullness too.