First post - hope I do this right!
Just bought a house with an in-ground vinyl liner pool. Been researching - found the manual for the Sand Dollar filter, but I do not understand what is this part attached in front of the strainer (which is in front of the pump motor). I think it has something to do with opening lines but nothing is marked. I am wondering if anyone knows what this is and what I do with it?
[attachment=1:2zcwulhf]what is this.jpg[/attachment:2zcwulhf]