I just moved into a new house and I need help understanding the pool plumbing. I moved from a house with a salt water pool and no spa. My old house pool had a port for the connection of a pool sweep as does the new pool. The old pool surface was pebble tec, the new pool surface is marcite. This new pool has a spa that overflows into the pool. Additionally the new pool has several white round disc shaped objects in the bottom of the pool.
Below is a picture of the new pool plumbing. I have labeled the pipes and valves as I believe they are.
My first question concerns the valves. All the valves except 1 and 5 have 3 pipes attached to them. I’m assuming these valves can direct incoming/outgoing water to either of the remaining 2 pipes but not both. So for example Valve 2 selects return water to either the Spa Return pipe or to Valve 3. In Valve 2’s current position it is returning water toward valve 3 but not the Spa Return pipe.
The incoming water from the pipe marked ? into valve 4 I believe is water from the pool sweep.
The return water pipe marked Pool return cleaner connected to Valve 3 I believe has something to do with those white discs on the bottom of the pool. Not sure though. I’m assuming the pipe marked pool return is return water to the 2 side pool jets.

I have more questions but I need to know if I have a basic understanding of how these valves work and where the pipes go.
Below is a picture of the new pool plumbing. I have labeled the pipes and valves as I believe they are.
My first question concerns the valves. All the valves except 1 and 5 have 3 pipes attached to them. I’m assuming these valves can direct incoming/outgoing water to either of the remaining 2 pipes but not both. So for example Valve 2 selects return water to either the Spa Return pipe or to Valve 3. In Valve 2’s current position it is returning water toward valve 3 but not the Spa Return pipe.
The incoming water from the pipe marked ? into valve 4 I believe is water from the pool sweep.
The return water pipe marked Pool return cleaner connected to Valve 3 I believe has something to do with those white discs on the bottom of the pool. Not sure though. I’m assuming the pipe marked pool return is return water to the 2 side pool jets.

I have more questions but I need to know if I have a basic understanding of how these valves work and where the pipes go.