New member, new to pools.
Bought this house less than a year ago. Lots of stuff to learn (about pools and about how the previous did or did not take care of stuff).
The basics: 9500 gal gunite pool. 1.5 HP pump. Cylindrical cartridge filter. Inline chlorinator. Some leaky PVC valves (vacuum line intake). Old stuff. But it runs. Pump is roughly 3 feet below the water level of the pool). A check valve after the filter (possibly not aligned correctly - the other one says 'this side up'. I can't see it.) and another after the chlorinator. Picture attached. Questionable check valve is middle/bottom, between the two lines with PVC ball valves. I thought they were all return lines. I originally assumed each return line went to a different jet. Now I don't think that's true.
Can someone explain this picture to me? All I know is this:
My regular pressure is about 26psi at the filter (new or clean filter). I've read that's too high generally. I asked the guy at the pool store about this and he thought maybe the pump or impeller was oversized. One day, while looking over the pool plumbing, I noticed that the flow arrow on the check valve on the middle pipe (union - spring type I think) on the return side was pointing back toward the filter (not toward the side going into the ground.).
Could this be right? Where do each of the 3 pipes going into the ground on the return side go? Are any of them possibly recirculating? I know if I cut off the flow to the one on the bottom (before it goes into the ground, all the jets still work. Not so the one on the Top. I have no idea what the middle one is doing.