I bought a house with a pool and moved in last week. I have never owned a house or pool before, so it's been a week of new experiences. I have been browsing this site quite a bit to get up to speed, and have spent way too much time at the pool store. I now have good chemical balance and clear water. However, my pump is randomly turning off and firing back up every few minutes. After speaking with an employee at the pool store, he suggested that my water level is too high, which in turn is causing the pump to shut off. I did some quick measurements and confirmed that the water is about 3 inches above the skimmer inlet. I believe that draining some water should fix my issue, but the previous owner did not label any of the valves and I have no idea how to proceed (all of the Youtube videos I watched had the valves labeled). What I do know is that I don't want my skimmer to be working when I drain because of the risk of it sucking in air, so I want to turn that off completely.
I have attached a photo of my system. As you can see, there are two blue valves, and a red valve. The red valve discharges the water (I confirmed that). The blue valve on the left cannot be opened all the way because it is blocked by the PVC piping on the left. The blue valve in the middle can be opened all the way. When I close it up (as it is currently pictured), it seems to me that my skimmer has less suction. When I open it up, it feels like my skimmer has much more suction. Is it possible that my main drain and skimmer share this valve, and opening/shutting it is basically switching between both? If so, does this mean I can never completely turn off the skimmer suction? Have any of you ever seen this type of setup?
I really appreciate all the help and insight contained in this forum, especially for us new pool owners. Thanks in advance!