I am a first year pool owner and have benefitted greatly from the information contained on this website. Since getting the pool I have inquired from a few other owners as to what the attached pictures are and nobody seems to know for sure. As you will see one is located just below the skimmer box and the other is located at the narrow end of the pool in the deep end. This second one has a plunger style head to it. Any assistance would be appreciated. :?: