the gurgling seems to be coming from the top of the filter where the pressure release valve is...i have read other posts suggesting air in the filter so i've opened the release valve while its running and let the water run out and i've also opened it while the pump is not running and i left it open until no more air escaped...still gurgles...this has just started in the last week or so and we have owned the house since may so it ran fine for several months...i am new to pool maintenance, and the pool company that i used instructed me on how to clean the pool but they neglected to tell me i needed to add diatomaceous earth every time i backwash so i have never added any...is it possible that this is the issue because i have back washed all the filter material out of the filter...i have some on order and until then i am running the multiport on recirculate instead of filter...thanks in advance for any advice