You might want to provide some details about the set up, such as how deep is the water it's sitting in, what your salinity is, what type of bioload do you have, how big is the tank, how is the venturi nozzle set up, etc.
If you have pictures of the skimmer running, that would help too.
No offense, but making a post like this would be like going on a car forum and saying "my Camero makes strange noises".
Anyway, hopefully someone here (maybe even myself, lol) will be able to help you with this once we have more information.