the pool came with house, and no matter what i do i can not get the filter to be silent. it always sounds like there is air in there.
i have replaced all my seals/gaskets, and i'm not losing any water, so i don't have a leak on the skimmer or main drain line, or the returns.
My guess is that there was something else hooked to the return line, and there is air getting stuck in the pipe that is capped off on the right.
also i'm thinking that the chlorinator is in the wrong spot, and should be before both return lines. That is the pipe coming directly off the pool, and bypassing the chlorinator are the jets that are pictured below
here is also a video of the sound
http://www.flickr.com/photos/35653728@N ... likes_hd=1