I have a 10k gal concrete pool with 3 returns running on a 1.5 hp pump. That’s the basic data. What I also have is a 4th opening on the wall between the skimmer and a return jet. It has a screw in cap that I have not removed(in case it was for excess ground water under pool to relieve pressure into the pool). I don’t know if this is suction or pressure wher I could add an additional jet directed at the bottom. Any ideas why this is capped and unused?
Hello Dave - Unfortunately, we can only guess as to why it is capped and unused. I doubt it’s for relieving pressure. Those types of plugs are usually in the main drain at the bottom of the pool. It’s probably a vac line. I don’t know whether it would be suction or pressure. That is something you’d have to find out by removing the cap.