First post but I've been doing a lot of research on this site since I bought my house and am now a new pool owner. The pool was installed in '96 and I've been slowly figuring everything out since I moved in, in September '13. I've got most everything under my belt but still had a couple questions about some of the plumbing.
1) There is a vent pipe sticking out of the ground at the equipment pad. What could this be going to? I do have a bench with "therapy jets" in the back but I've never been able to get bubbles unless I plug one up with a finger and then pull it out.
2) I have a valve that directs water to the returns or the in-floor cleaning system. On the return side it Tees. Then on one side it goes through a check valve and connects with the in-floor side of the valve. Why would this be plumbed this way?